Ultrasound-Guided Percutaneous Core Biopsy of Renal Sinus Masses: Diagnostic Yield, Safety, and Clinical Impact

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Reliable tissue acquisition is essential for guiding treatment decisions, yet evidence on the performance of ultrasound (US)-guided biopsy in this setting remains limited. Objective We retrospectively analyzed 51 patients who underwent US-guided percutaneous core needle biopsy of renal sinus masses at a tertiary medical center (2010–2020). Inclusion criteria were renal sinus masses with indeterminate imaging features. Diagnostic yield, histological results, complication rates (Clavien–Dindo classification), and subsequent treatment modifications were assessed. Univariate logistic regression was performed to explore factors associated with complications. Results Biopsy achieved a diagnostic yield of 90.2% (46/51). Malignant lesions accounted for 88.2% of cases, most commonly upper-tract urothelial carcinoma of the renal pelvis (43.1%) and clear cell renal cell carcinoma (31.4%). Benign lesions comprised 11.8%. The overall complication rate was 7.8% (4/51), limited to grade I–II events (perirenal hematoma, hematuria); no major complications or needle tract seeding were observed. Biopsy findings altered treatment in 23.5% of patients, and unnecessary surgery was avoided in 7.8%. Tumor size, location, and number of needle passes were not significantly associated with complications (all P > 0.05). Conclusion US-guided percutaneous core biopsy of renal sinus masses is a safe and effective diagnostic approach, providing high tissue yield with low morbidity. By enabling accurate diagnosis and reducing overtreatment, this technique represents a valuable tool in the management of complex renal tumors. Ultrasound-guided biopsy renal sinus mass diagnostic accuracy complication rate upper-tract urothelial carcinoma Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Image-guided percutaneous biopsy plays a central role in modern oncology, contributing not only to initial diagnosis and tumor staging but also to treatment monitoring, evaluation of residual disease, and confirmation of recurrence [ 1 ] . For patients who are poor surgical candidates, biopsy provides a pathway to alternative strategies such as active surveillance or thermal ablation. With the expansion of targeted therapies in the era of precision medicine, the ability to obtain high-quality tissue samples has become increasingly critical for molecular subtyping and biomarker testing [ 2 – 4 ] . Among imaging modalities, ultrasound (US) and computed tomography (CT) remain the most widely used. US has gained particular prominence owing to its convenience, real-time visualization, and lack of ionizing radiation, making it one of the preferred methods for image-guided interventions [ 5 ] . Recent advances have further extended the role of US in biopsies of lesions located in anatomically complex regions. Biopsies of the renal sinus, however, remain technically demanding because of the intricate anatomy and proximity to critical structures such as the renal vasculature and ureter [ 6 , 7 ] . Nevertheless, US guidance offers precise targeting and real-time monitoring, enabling safe tissue acquisition even in this challenging location [ 8 ] . The renal sinus accommodates a diverse spectrum of pathologies, including upper-tract urothelial carcinoma(UTUC), renal cell carcinoma(RCC), lymphoma, metastases, and benign entities such as angiomyolipoma and inflammatory pseudotumor [ 9 – 12 ] . UTUC is the most common malignancy in this region, yet the overlapping imaging features of other tumors often hinder accurate differentiation. Given this histological heterogeneity, imaging alone is frequently insufficient, and histopathological confirmation is essential for guiding appropriate treatment strategies [ 13 ] . Although previous studies have established the safety and efficacy of US-guided biopsy for renal parenchymal masses [ 14 – 17 ] , systematic investigations specifically addressing renal sinus lesions remain limited. The available data are largely restricted to small series, leaving diagnostic accuracy and complication profiles insufficiently characterized. At our institution, clinical experience has allowed the accumulation of a relatively large cohort of patients who underwent US-guided renal sinus biopsy. This provides an opportunity for a more robust evaluation. Accordingly, the present study retrospectively analyzes these cases to assess the diagnostic performance, technical feasibility, and safety of US-guided core needle biopsy of renal sinus masses, as well as its impact on subsequent clinical management. Materials and Methods Declarations The requirement for informed consent was waived by the institutional review board due to the retrospective nature of the study. Study Population Using the ultrasound workstation (Lanwon, version: V7 Build1560312), we retrospectively identified patients who were referred to our ultrasound department between 2010 and 2020 for percutaneous ultrasound-guided core needle biopsy of renal sinus masses with indeterminate imaging features. A preliminary screening using the keywords "kidney" and "biopsy" identified a total of 133 patients. Of these, 71 patients who underwent renal parenchymal biopsies (i.e., targeting the cortex or medulla) rather than renal sinus biopsies (i.e., targeting peripelvic fat, vessels, and lymphatics, which appear hyperechoic on renal ultrasound; see Figure 1) were excluded. We subsequently reviewed the electronic medical records of 62 patients who met the criteria for ultrasound-guided renal sinus core needle biopsy. Data collected included demographic information (age, sex); mass characteristics (size, location, solid or cystic-solid composition, RENAL score); procedural details (number of biopsy cores, total specimen length and complications); pathological diagnosis (histopathology or surgical pathology); and subsequent clinical management (diagnostic yield, histological subtype, post-biopsy imaging follow-up for late complications or needle tract seeding, follow-up duration, need for repeat biopsy, and treatment outcomes). For patients who subsequently underwent surgical resection, the histological findings from the biopsy were compared with the final surgical pathology to determine diagnostic accuracy. Eleven patients were excluded due to incomplete clinical data (missing imaging or medical records), resulting in a final cohort of 51 eligible patients(Figure 2). All patients were evaluated by a multidisciplinary tumor board at our institution, comprising specialists in medical oncology, urology, diagnostic radiology, and interventional ultrasound. Patients were considered eligible for renal sinus biopsy if they met at least one of the following criteria: (1) clinical history and prior imaging studies (i.e., contrast-enhanced CT or magnetic resonance imaging [MRI]) suggested a renal sinus mass without a definitive benign or malignant diagnosis, or (2) histological confirmation was required to guide clinical treatment, such as targeted therapy. Equipment Ultrasound examinations were performed using Philips iU22 and GE Vivid 7 Dimension color Doppler systems, equipped with linear-array transducers (5–12 MHz) and convex-array transducers (2–5 MHz). Ultrasound-Guided Renal Sinus Biopsy All patients underwent routine preoperative laboratory tests, including complete blood count, biochemical profile, and coagulation function assessment, as well as imaging evaluations with CT or MRI. The interventional radiologist carefully reviewed preoperative imaging to assess the location of the renal sinus lesion and its relationship to adjacent structures. A pre-biopsy ultrasound scan was performed, with contrast-enhanced ultrasound (CEUS) used to identify solid components as biopsy targets. The puncture site was routinely disinfected and draped, followed by local infiltration anesthesia. Under in-plane ultrasound guidance, a 15G coaxial introducer needle was advanced to the lesion margin. After removal of the inner stylet, a 16G core-cutting biopsy needle (Zhejiang Curaway Medical Technology Inc., China) was loaded into an automatic biopsy gun to obtain tissue samples (Figure 3). The inner core was then reinserted, and the radiofrequency generator was activated to deliver thermal ablation via the working electrode at the tip of the outer sheath. The needle was held in place until the target temperature was reached, then slowly withdrawn until fully removed from the kidney. Post-Procedure Management The number of biopsy passes was determined by the operator based on the gross appearance of the specimens, without on-site pathological assessment. All procedures were performed under local anesthesia by two senior interventional radiologists (W.S.S., 20 years of experience; Y.J.C., 15 years). After the procedure, manual compression was applied for 5 minutes, followed by sterile dressing. Patients were monitored with ultrasound for 30–60 minutes to exclude acute bleeding, remained on bed rest for 2 hours, and were discharged the following day after overnight observation. Pathology Evaluation All biopsy specimens were reviewed by a dedicated urogenital pathologist with 15 years of experience (W.C.). Histological diagnoses were recorded and subsequently correlated with clinical outcomes and complication assessment. Follow-Up and Complication Assessment All patients underwent standardized post-biopsy surveillance. Ultrasound was performed at 1, 3, and 6 months, with contrast-enhanced CT or MRI at 6–12 month intervals, for a minimum of 12 months. Follow-up images were systematically reviewed for local recurrence or tract seeding. Two experienced radiologists independently evaluated all imaging, with discrepancies resolved by consensus. Evaluation Criteria The complexity of renal masses was assessed using the RENAL nephrometry score, based on the method proposed by Kutikov and Uzzo [18] ; postoperative complications were graded according to the Clavien–Dindo classification system [19] . Pathological evaluation: A diagnosis was considered successful if the pathology revealed malignancy, or if a benign diagnosis was confirmed by ≥12 months of stable imaging follow-up. Conversely, a diagnosis was deemed inaccurate if a lesion initially diagnosed as benign showed progression on follow-up imaging or was later found to contain malignant components on repeat biopsy or surgery. Statistical Analysis Statistical analyses were performed using SPSS software, version 26.0 (IBM Corp., Armonk, NY, USA). Categorical variables are presented as frequencies and percentages, while continuous variables are expressed as medians with ranges. The overall diagnostic success rate and complication rate of ultrasound-guided percutaneous biopsy of renal sinus masses were calculated. To identify factors associated with diagnostic success and complications, univariate logistic regression using Firth’s penalized likelihood method was employed. Variables included maximum tumor diameter (>30 mm vs. ≤30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum and number of punctures (1–4) (for complication analysis). Results were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Statistical significance was defined as a two-sided p -value of <0.05. Results Patient and Tumor Characteristics A total of 51 patients who underwent ultrasound-guided percutaneous core needle biopsy of renal sinus masses were included in the study. Of these, 29 were male (56.86%) and 22 were female (43.14%). The median age was 63 years (range: 19–85 years). The median maximum tumor diameter was 31 mm (range: 13–78 mm). Heterogeneous enhancement was observed in 56.86% of lesions (29/51). According to the RENAL nephrometry scoring system, 88.23% of lesions (45/51) were classified as highly complex (scores of 10–12), and 11.77% were moderately complex (scores of 7–9); no low-complexity tumors were identified. Baseline patient characteristics are summarized in Table 1. Diagnostic Performance and Histopathological Findings In this study, the overall diagnostic success rate of ultrasound-guided percutaneous biopsy of renal sinus masses was 90.20% (46/51); among the 46 cases, 5 were benign and 41 were malignant. 5 cases (9.80%) yielded non-diagnostic results due to insufficient tissue or necrosis. In two cases, the initial biopsy yielded only one tissue core, which was insufficient for diagnosis; both were later confirmed by surgery to be UTUC. One lesion exhibited extensive central necrosis with no viable area on CEUS, and was confirmed postoperatively as RCC (Fuhrman grade III). In one case, severe fibrosis in the biopsy specimen precluded diagnosis; laparoscopic biopsy later confirmed a solitary fibrous tumor. One case was complicated by intraoperative bleeding that interfered with sampling; a second CT-guided biopsy confirmed metastatic adenocarcinoma originating from the lung. Univariate logistic regression analysis showed no significant associations between diagnostic success and tumor size (>30 mm vs. ≤30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum, or number of biopsy passes (1–4) (Table 3). Comprehensive pathological data of the 51 cases are presented in Table 2. Complication Analysis The overall complication rate of ultrasound-guided percutaneous biopsy of renal sinus masses was 7.84% (4/51), including three cases of perirenal hematoma (15–20 mm in diameter) and one case of gross hematuria, all classified as Clavien–Dindo grade I–II. Details of management and outcomes are as follows: Case 1 : Immediate postoperative ultrasound revealed a 15 mm hematoma. The patient remained hemodynamically stable and was managed with local compression and extended bed rest (6 hours). The hematoma resolved spontaneously within one week, as confirmed on follow-up ultrasound. Case 2 : Minor bleeding occurred during the procedure. Thrombin (500 IU) was injected via the coaxial sheath to embolize the needle tract. The patient was observed for 24 hours postoperatively without the need for further intervention. Case 3 : The patient developed mild flank pain 24 hours post-procedure. Ultrasound confirmed a 20 mm perirenal hematoma. Symptomatic treatment with analgesia and an extended hospital stay (48 hours) was provided. The hematoma resolved completely by one-month follow-up. Case 4 (hematuria) : Gross hematuria developed 6 hours after biopsy. The patient was treated with intravenous tranexamic acid and absolute bed rest. Hematuria resolved within 24 hours without evidence of coagulopathy or thrombotic events. No major complications such as arteriovenous fistula, significant hemorrhage, or nephrectomy were observed. Univariate logistic regression analysis showed no significant associations between complication occurrence and tumor size (>30 mm vs. ≤30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum, number of biopsy passes (1–4) (Table 4). All available post-biopsy axial imaging data were retrospectively reviewed to evaluate for delayed complications and needle tract seeding. As of the time of data collection, five patients had no imaging or clinical follow-up. Among the remaining 46 patients, the median imaging follow-up period was 5 years (range: 0.2–12 years). No imaging findings suggestive of delayed complications or tumor seeding along the biopsy tract were identified. Impact on Clinical Decision-Making Biopsy results altered the treatment strategy in 23.5% (12/51) of patients, including 7.8% (4/51) in whom unnecessary surgery was avoided(Figure 5、Suppl. Fig. 1). Among the 46 patients with available treatment data, 27 underwent surgery alone—23 underwent radical nephrectomy and 4 underwent partial nephrectomy(Suppl. Fig. 2、Suppl. Fig. 3、Suppl. Fig. 4). One patient received medical, two patients received ablation therapy, one received chemotherapy, and five were managed with active surveillance. Ten patients underwent combination therapy, including chemotherapy plus surgery in seven cases and chemotherapy plus radiotherapy in three (Table 5、Figure 4). Table 1 Patient and Tumor Characteristics Patients Characteristic N=51 N % Age (years) Median 63 Range (mean) 19-85（64.29） Gender Female 22 43.14 Male 29 56.86 Maximum Diameter Median 31 Range (mean) 13-78（30.09） Laterality Left 27 52.94 Right 24 47.06 Enhancement Pattern Homogeneous 22 43.14 Heterogeneous 29 56.86 RENAL nephrometry score Low（4-6） 0 0 Moderate（7-9） 6 11.76 High（10-12） 45 88.24 Table 2 Pathological Results Diagnostic N % Benign Angiomyolipoma 2 3.92 Eosinophilic Adenoma 2 3.92 Solitary Fibrous Tumor 1 1.96 IgG4-related Kidney Disease 1 1.96 Malignant UTUC 22 43.14 RCC, clear cell 16 31.37 RCC, papillary 2 3.92 RCC, chromophobe 1 1.96 Metastatic 3 5.88 Lymphoma 1 1.96 Note.—UTUC, upper-tract urothelial carcinoma, RCC, renal cell carcinoma Table 3 Univariate Logistic Regression Model for Diagnostic Success Rate Parameter level Successful Diagnoses / Total OR （ CI ） P -value Maximum diameter ≤30 mm 4/33 — — >30 mm 1/18 0.43(0.04–4.12) 0.64 Location Upper 2/7 — — Mid 3/32 0.26(0.03 - 1.95) 0.25 Lower 0/12 0.08 (0.00 - 1.97) 0.20 Nearness to hilum Not near 2/31 — — Near 3/20 2.56（0.39 - 16.78） 0.34 Biopsy cores (N) 1 2/6 — — 2 3/19 0.38 (0.01 - 0.50) 0.19 3 0/17 0.05 (0.00 - 1.19) 0.10 4 0/9 0.09 (0.00 - 2.29) 0.27 Table 4 Univariate Logistic Regression Model for Complications Parameter level Complications / Total OR （ CI ） P -value Maximum diameter ≤30 mm 2/33 — — >30 mm 2/18 1.94 (0.25–15.07) 0.61 Location Upper 1/12 — — Mid 3/32 1.14 (0.13 - 10.18) 0.56 Lower 0/7 0.54 (0.02 - 6.23) 1.00 Nearness to hilum Not near 2/31 — — Near 2/20 0.33（0.02, 3.52） 0.42 Biopsy cores (N) 1 1/6 — — 2 2/19 0.59 (0.04 - 5.15) 0.63 3 0/17 0.10 (0.00 - 3.07) 0.32 4 1/9 0.63(0.03 - 6.82) 1.00 Table 5 Details of 12 Cases with Treatment Modification No. Pre-biopsy Suspicion Biopsy Pathology Treatment Change 1 UTUC IgG4-related Kidney Disease Radical nephrectomy → Medical therapy 2 UTUC Lymphoma Radical nephrectomy → Chemotherapy 3 RCC Eosinophilic Adenoma Partial nephrectomy → Active surveillance 4 Inflammation UTUC Medical therapy → Radical nephrectomy 5 Malignant Angiomyolipoma Partial nephrectomy → Active surveillance 6 Benign UTUC Partial nephrectomy → Radical nephrectomy 7 RCC UTUC Partial nephrectomy → Radical nephrectomy 8 RCC UTUC Partial nephrectomy → Radical nephrectomy 9 UTUC RCC Radical nephrectomy → Partial nephrectomy 10 UTUC RCC Radical nephrectomy → Partial nephrectomy 11 RCC Eosinophilic Adenoma Partial nephrectomy → Active surveillance 12 UTUC RCC Radical nephrectomy → Partial nephrectomy Note.—UTUC, upper-tract urothelial carcinoma, RCC, renal cell carcinoma Discussion Our retrospective analysis of 51 patients undergoing ultrasound-guided percutaneous renal sinus core needle biopsy shows that this approach achieves a high diagnostic yield while maintaining a favorable safety profile in complex renal masses. According to current European Association of Urology (EAU) guidelines, the diagnostic work-up for suspected UTUC relies on CT urography, ureteroscopic biopsy, and urine cytology [20] . Each of these techniques has recognized shortcomings: CT urography lacks sensitivity for small or flat lesions, ureteroscopic biopsy is technically demanding with variable success rates (70–90%), and urine cytology performs poorly for low-grade disease. Within this context, the 90.2% diagnostic success and low incidence of only minor complications (5.9%) in our series suggest that ultrasound-guided renal sinus biopsy provides a valuable complementary tool, particularly in cases where imaging is inconclusive or ureteroscopic biopsy is unsuccessful, and when histological subtyping is needed to guide systemic therapy. Diagnostic outcomes for renal parenchymal biopsy have been well established, with reported accuracy ranging from 85–97% and complication rates generally low [21–30] . Core biopsy consistently outperforms fine-needle aspiration [31] . In contrast, data specific to renal sinus lesions remain limited. While MRI guidance offers superior soft-tissue contrast and is often recommended for anatomically challenging locations, our findings indicate that ultrasound-guided biopsy achieves a comparable diagnostic accuracy (90.2% vs. 90–96%) [32] . The consistent use of core needles and contrast-enhanced ultrasound in our cohort likely contributed to this performance by enabling precise, real-time targeting while avoiding necrotic or cystic regions. Unlike MRI, ultrasound is widely available, less costly, and simpler to perform, making it more adaptable to routine clinical practice. Despite the anatomical complexity of the renal sinus, including its proximity to major vessels and the ureter, a high diagnostic yield was achieved even in highly complex tumors (RENAL score 10–12, 88.2%). The few biopsy failures (9.8%) were largely attributable to limited tissue volume or necrosis, indicating that ultrasound guidance remains technically reliable even in challenging cases. The overall complication rate was 7.8%, all Clavien–Dindo grade I–II (perirenal hematoma and gross hematuria). All events resolved with conservative management, and no major bleeding, interventions, or tract seeding were observed. These findings are consistent with the reported complication rates for renal parenchymal biopsy (3–10%). The ability of real-time ultrasound to guide the needle path and avoid major vessels likely contributes to the low incidence of severe hemorrhage. Even so, international guidelines remain cautious about percutaneous biopsy in suspected UTUC, citing risks of tumor seeding and under-sampling, and generally do not recommend it as a first-line diagnostic approach [33] . In this context, renal sinus biopsy should be considered an adjunct rather than a replacement for established modalities, and reserved for carefully selected patients in experienced centers. Needle tract seeding has been reported in 0.01–6% of renal biopsies [13] , although the true incidence is likely underestimated in patients who do not undergo surgery [34] . In our study, the use of coaxial systems combined with immediate tract ablation, along with standardized follow-up using ultrasound and cross-sectional imaging, revealed no evidence of seeding. Independent review by two radiologists further confirmed the absence of delayed complications. Nevertheless, the median follow-up of five months was relatively short, and late-onset recurrence cannot be excluded. Larger, multicenter studies with longer follow-up will be needed to establish the long-term safety profile of this procedure. Renal biopsy not only establishes a diagnosis but also directly shapes therapeutic decision-making. In our cohort, biopsy results modified management in 23.5% of patients, and 7.8% avoided unnecessary surgery owing to benign pathology. Precise histological subtyping was critical—particularly distinguishing UTUC (43.1%) from clear cell RCC (31.4%)—as these entities demand fundamentally different treatment strategies: systemic therapy and ureterectomy for UTUC versus nephron-sparing surgery for RCC [35] . Such diagnostic clarity is increasingly important in the era of targeted and immune therapies, where molecular and histological confirmation guide systemic treatment selection. These findings highlight the contribution of ultrasound-guided renal sinus biopsy to personalized management, especially for patients with indeterminate imaging, suspected metastases requiring subtyping, or significant surgical risk. This study has several limitations. It was a single-center retrospective analysis with a modest sample size, which limits statistical power and may introduce selection bias. Follow-up was incomplete in five patients, and in some cases too short to fully evaluate delayed complications such as tract seeding. Not all cases were confirmed surgically (39 patients underwent resection), raising the possibility of overestimating diagnostic accuracy. All procedures were performed by two highly experienced radiologists, which may restrict generalizability and implies a learning curve that should be characterized in future studies. In addition, no direct comparison was made with CT- or MRI-guided biopsy, limiting conclusions about relative performance. Finally, although no tract seeding was observed during a median follow-up of five years, longer-term multicenter prospective studies will be needed to validate safety and durability. Conclusion Ultrasound-guided percutaneous core needle biopsy of renal sinus masses is a safe and effective method that provides essential diagnostic information and supports clinical decision-making. Despite anatomical challenges, its real-time imaging and lack of radiation highlight its value in renal tumor management. With ongoing technological advances, this technique may further optimize patient care pathways. Abbreviations US ：ultrasound CT ：computed tomography MRI ：magnetic resonance imaging CEUS ：contrast-enhanced ultrasound CI ：confidence interval OR ：odds ratio UTUC: upper-tract urothelial carcinoma RCC ：renal cell carcinoma Declarations Ethical Approval and Consent to participate This study was approved by the Ethics Committee of Fujian Provincial Hospital. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments. The requirement for informed consent was waived because of the retrospective nature of this study. Consent for publication Not applicable. Availability of data and materials The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This study was supported by the Fujian Provincial Department of Finance (Grant No. Min Cai Zhi [2024] 881, Project Code: 0060092410). Authors’ contributions L.X. contributed to conceptualization, data curation, formal analysis, investigation, methodology, software, validation, visualization, and prepared the original draft of the manuscript. Z.X.T. contributed to conceptualization, data curation, investigation, and manuscript review and editing. S.M.J. contributed to methodology, validation, and manuscript review and editing. H.Z.L. contributed to methodology, validation, and manuscript review and editing. W.S.S. contributed to conceptualization, funding acquisition, investigation, methodology, project administration, resources, supervision, and writing of both the original draft and the revised manuscript. All authors reviewed and approved the final manuscript. L.X. and Z.X.T. contributed equally to this work and are designated as co-first authors. Acknowledgements The authors are thankful to Fujian Provincial Hospital and Fujian Medical University for their management of our patient database. The authors are thankful to Song-Song Wu for helping critically revise the manuscript for important intellectual content and helping collect data and design the study. References Clark DP. Seize the opportunity: underutilization of fine-needle aspiration biopsy to inform targeted cancer therapy decisions. Cancer. 2009;117:289–97. Volpe A, Finelli A, Gill IS, et al. Rationale for percutaneous biopsy and histologic characterisation of renal tumours. Eur Urol. 2012;62:491–504. 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Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Published Journal Publication published 24 Dec, 2025 Read the published version in Cancer Imaging → Version 1 posted Editorial decision: Revision requested 13 Nov, 2025 Reviews received at journal 31 Oct, 2025 Reviews received at journal 23 Oct, 2025 Reviewers agreed at journal 22 Oct, 2025 Reviewers agreed at journal 22 Oct, 2025 Reviewers agreed at journal 13 Oct, 2025 Reviews received at journal 10 Oct, 2025 Reviewers agreed at journal 09 Oct, 2025 Reviewers invited by journal 09 Oct, 2025 Editor assigned by journal 09 Oct, 2025 Submission checks completed at journal 08 Oct, 2025 First submitted to journal 03 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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2","display":"","copyAsset":false,"role":"figure","size":133269,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of patient selection.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/2c44363054e5d8e2c5522c9d.png"},{"id":94215614,"identity":"4d89d3e9-04f5-4c22-916e-8cd400eb6268","added_by":"auto","created_at":"2025-10-23 16:34:11","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":459544,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of the puncture procedure. During the procedure, a region with contrast enhancement and favorable accessibility on contrast-enhanced ultrasound should be selected to ensure the shortest and safest puncture path. After the needle enters the renal capsule, care should be taken to avoid arcuate arteries. The trajectory should also avoid the renal columns and the collecting system. Real-time color Doppler monitoring must be employed, and needle advancement should be stopped immediately if arterial signals are detected. The needle should then be angle-adjusted and advanced slowly and steadily at a speed of less than 2 mm/s to minimize the risk of tissue tearing.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/2c8f72dd87662e6f2a4458a2.png"},{"id":94215243,"identity":"b9d0b03e-262d-43a3-a277-4c357125eacd","added_by":"auto","created_at":"2025-10-23 16:26:11","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":208583,"visible":true,"origin":"","legend":"\u003cp\u003eChanges in Treatment Strategies Following Biopsy\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/29b1995d436b213a6f74a40d.png"},{"id":94214706,"identity":"e85c8584-fa94-4514-bbec-ca00c92bb56c","added_by":"auto","created_at":"2025-10-23 16:18:11","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":914837,"visible":true,"origin":"","legend":"\u003cp\u003eImaging findings and interventional diagnosis and treatment of a left renal mass in an 85-year-old male patient after right nephrectomy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(A)\u003c/strong\u003e Two-dimensional ultrasound (convex probe, 3.5 MHz) revealed an irregular hypoechoic mass (45 mm × 28 mm) in the left renal sinus with poorly defined margins, exhibiting infiltrative growth along the renal pelvis (arrow).\u003cbr\u003e\n \u003cstrong\u003e(B)\u003c/strong\u003e Color Doppler imaging (sampling box angled 30°, PRF 800 Hz) showed scattered punctate flow signals within the lesion, suggesting mild neovascularization.\u003cbr\u003e\n \u003cstrong\u003e(C)\u003c/strong\u003e Contrast-enhanced CT (arterial phase, slice thickness: 2 mm) demonstrated a hypovascular lesion in the renal pelvis with a “fast-in, slow-out” enhancement pattern, raising suspicion for renal pelvic carcinoma.\u003cbr\u003e\n \u003cstrong\u003e(D)\u003c/strong\u003e Contrast-enhanced ultrasound using SonoVue® (mechanical index 0.08) showed homogeneous, mildly hypoenhancing lesion with clear demarcation from the surrounding renal parenchyma.\u003cbr\u003e\n \u003cstrong\u003e(E)\u003c/strong\u003e Ultrasound-guided percutaneous biopsy of the left renal sinus was performed using an 18G semi-automatic core needle at a 22° angle. The needle trajectory and tip (triangle marker) were clearly visualized in real time. Pathological examination confirmed IgG4-related kidney disease.\u003cbr\u003e\n \u003cstrong\u003e(F)\u003c/strong\u003e Follow-up after one year of high-dose methylprednisolone therapy showed significant lesion shrinkage on ultrasound, with reduction in lesion size to 22 mm × 15 mm (a 62% decrease from baseline), supporting the efficacy of medical treatment.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/2b7928be4bdcda6344ded185.png"},{"id":99172428,"identity":"95bf62de-049c-46e3-9d76-d22b2001ba59","added_by":"auto","created_at":"2025-12-29 16:09:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3366250,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/446110b0-276f-4091-aa06-569baa7c05e0.pdf"},{"id":94214301,"identity":"463c55b5-0c3f-45e5-8b06-fbe99fd82e99","added_by":"auto","created_at":"2025-10-23 16:10:12","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":2405209,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-7771586/v1/0eb27fb0e77739b2f2dfda4e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ultrasound-Guided Percutaneous Core Biopsy of Renal Sinus Masses: Diagnostic Yield, Safety, and Clinical Impact","fulltext":[{"header":"Introduction","content":"\u003cp\u003eImage-guided percutaneous biopsy plays a central role in modern oncology, contributing not only to initial diagnosis and tumor staging but also to treatment monitoring, evaluation of residual disease, and confirmation of recurrence\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. For patients who are poor surgical candidates, biopsy provides a pathway to alternative strategies such as active surveillance or thermal ablation. With the expansion of targeted therapies in the era of precision medicine, the ability to obtain high-quality tissue samples has become increasingly critical for molecular subtyping and biomarker testing\u003csup\u003e[\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Among imaging modalities, ultrasound (US) and computed tomography (CT) remain the most widely used. US has gained particular prominence owing to its convenience, real-time visualization, and lack of ionizing radiation, making it one of the preferred methods for image-guided interventions\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eRecent advances have further extended the role of US in biopsies of lesions located in anatomically complex regions. Biopsies of the renal sinus, however, remain technically demanding because of the intricate anatomy and proximity to critical structures such as the renal vasculature and ureter\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e. Nevertheless, US guidance offers precise targeting and real-time monitoring, enabling safe tissue acquisition even in this challenging location\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. The renal sinus accommodates a diverse spectrum of pathologies, including upper-tract urothelial carcinoma(UTUC), renal cell carcinoma(RCC), lymphoma, metastases, and benign entities such as angiomyolipoma and inflammatory pseudotumor\u003csup\u003e[\u003cspan additionalcitationids=\"CR10 CR11\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. UTUC is the most common malignancy in this region, yet the overlapping imaging features of other tumors often hinder accurate differentiation. Given this histological heterogeneity, imaging alone is frequently insufficient, and histopathological confirmation is essential for guiding appropriate treatment strategies\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAlthough previous studies have established the safety and efficacy of US-guided biopsy for renal parenchymal masses\u003csup\u003e[\u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e, systematic investigations specifically addressing renal sinus lesions remain limited. The available data are largely restricted to small series, leaving diagnostic accuracy and complication profiles insufficiently characterized. At our institution, clinical experience has allowed the accumulation of a relatively large cohort of patients who underwent US-guided renal sinus biopsy. This provides an opportunity for a more robust evaluation. Accordingly, the present study retrospectively analyzes these cases to assess the diagnostic performance, technical feasibility, and safety of US-guided core needle biopsy of renal sinus masses, as well as its impact on subsequent clinical management.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cstrong\u003eDeclarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe requirement for informed consent was waived by the institutional review board due to the retrospective nature of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUsing the ultrasound workstation (Lanwon, version: V7 Build1560312), we retrospectively identified patients who were referred to our ultrasound department between 2010 and 2020 for percutaneous ultrasound-guided core needle biopsy of renal sinus masses with indeterminate imaging features. A preliminary screening using the keywords \u0026quot;kidney\u0026quot; and \u0026quot;biopsy\u0026quot; identified a total of 133 patients.\u0026nbsp;Of these, 71 patients who underwent renal parenchymal biopsies (i.e., targeting the cortex or medulla) rather than renal sinus biopsies (i.e., targeting peripelvic fat, vessels, and lymphatics, which appear hyperechoic on renal ultrasound; see Figure 1) were excluded.\u003c/p\u003e\n\u003cp\u003eWe subsequently reviewed the electronic medical records of 62 patients who met the criteria for ultrasound-guided renal sinus core needle biopsy. Data collected included demographic information (age, sex); mass characteristics (size, location, solid or cystic-solid composition, RENAL score); procedural details (number of biopsy cores, total specimen length and complications); pathological diagnosis (histopathology or surgical pathology); and subsequent clinical management (diagnostic yield, histological subtype, post-biopsy imaging follow-up for late complications or needle tract seeding, follow-up duration, need for repeat biopsy, and treatment outcomes).\u003c/p\u003e\n\u003cp\u003eFor patients who subsequently underwent surgical resection, the histological findings from the biopsy were compared with the final surgical pathology to determine diagnostic accuracy. Eleven patients were excluded due to incomplete clinical data (missing imaging or medical records), resulting in a final cohort of 51 eligible patients(Figure 2).\u003c/p\u003e\n\u003cp\u003eAll patients were evaluated by a multidisciplinary tumor board at our institution, comprising specialists in medical oncology, urology, diagnostic radiology, and interventional ultrasound. Patients were considered eligible for renal sinus biopsy if they met at least one of the following criteria: (1) clinical history and prior imaging studies (i.e., contrast-enhanced CT or magnetic resonance imaging [MRI]) suggested a renal sinus mass without a definitive benign or malignant diagnosis, or (2) histological confirmation was required to guide clinical treatment, such as targeted therapy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEquipment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eUltrasound examinations were performed using Philips iU22 and GE Vivid 7 Dimension color Doppler systems, equipped with linear-array transducers (5\u0026ndash;12 MHz) and convex-array transducers (2\u0026ndash;5 MHz).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUltrasound-Guided Renal Sinus Biopsy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients underwent routine preoperative laboratory tests, including complete blood count, biochemical profile, and coagulation function assessment, as well as imaging evaluations with CT or MRI.\u0026nbsp;The interventional radiologist carefully reviewed preoperative imaging to assess the location of the renal sinus lesion and its relationship to adjacent structures. A pre-biopsy ultrasound scan was performed, with contrast-enhanced ultrasound (CEUS) used to identify solid components as biopsy targets.\u0026nbsp;The puncture site was routinely disinfected and draped, followed by local infiltration anesthesia. Under in-plane ultrasound guidance, a 15G coaxial introducer needle was advanced to the lesion margin. After removal of the inner stylet, a 16G core-cutting biopsy needle (Zhejiang Curaway Medical Technology Inc., China) was loaded into an automatic biopsy gun to obtain tissue samples (Figure 3).\u0026nbsp;The inner core was then reinserted, and the radiofrequency generator was activated to deliver thermal ablation via the working electrode at the tip of the outer sheath. The needle was held in place until the target temperature was reached, then slowly withdrawn until fully removed from the kidney.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePost-Procedure Management\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe number of biopsy passes was determined by the operator based on the gross appearance of the specimens, without on-site pathological assessment. All procedures were performed under local anesthesia by two senior interventional radiologists (W.S.S., 20 years of experience; Y.J.C., 15 years). After the procedure, manual compression was applied for 5 minutes, followed by sterile dressing. Patients were monitored with ultrasound for 30\u0026ndash;60 minutes to exclude acute bleeding, remained on bed rest for 2 hours, and were discharged the following day after overnight observation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePathology Evaluation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll biopsy specimens were reviewed by a dedicated urogenital pathologist with 15 years of experience (W.C.). Histological diagnoses were recorded and subsequently correlated with clinical outcomes and complication assessment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFollow-Up and Complication Assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients underwent standardized post-biopsy surveillance. Ultrasound was performed at 1, 3, and 6 months, with contrast-enhanced CT or MRI at 6\u0026ndash;12 month intervals, for a minimum of 12 months. Follow-up images were systematically reviewed for local recurrence or tract seeding. Two experienced radiologists independently evaluated all imaging, with discrepancies resolved by consensus.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEvaluation Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe complexity of renal masses was assessed using the RENAL nephrometry score, based on the method proposed by Kutikov and Uzzo\u003csup\u003e[18]\u003c/sup\u003e; postoperative complications were graded according to the Clavien\u0026ndash;Dindo classification system\u003csup\u003e[19]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003ePathological evaluation: A diagnosis was considered successful if the pathology revealed malignancy, or if a benign diagnosis was confirmed by \u0026ge;12 months of stable imaging follow-up. Conversely, a diagnosis was deemed inaccurate if a lesion initially diagnosed as benign showed progression on follow-up imaging or was later found to contain malignant components on repeat biopsy or surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using SPSS software, version 26.0 (IBM Corp., Armonk, NY, USA). Categorical variables are presented as frequencies and percentages, while continuous variables are expressed as medians with ranges. The overall diagnostic success rate and complication rate of ultrasound-guided percutaneous biopsy of renal sinus masses were calculated. To identify factors associated with diagnostic success and complications, univariate logistic regression using Firth\u0026rsquo;s penalized likelihood method was employed. Variables included maximum tumor diameter (\u0026gt;30 mm vs. \u0026le;30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum and number of punctures (1\u0026ndash;4) (for complication analysis). Results were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Statistical significance was defined as a two-sided \u003cem\u003ep\u003c/em\u003e-value of \u0026lt;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003ePatient and Tumor Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 51 patients who underwent ultrasound-guided percutaneous core needle biopsy of renal sinus masses were included in the study. Of these, 29 were male (56.86%) and 22 were female (43.14%). The median age was 63 years (range: 19\u0026ndash;85 years). The median maximum tumor diameter was 31 mm (range: 13\u0026ndash;78 mm). Heterogeneous enhancement was observed in 56.86% of lesions (29/51). According to the RENAL nephrometry scoring system, 88.23% of lesions (45/51) were classified as highly complex (scores of 10\u0026ndash;12), and 11.77% were moderately complex (scores of 7\u0026ndash;9); no low-complexity tumors were identified. Baseline patient characteristics are summarized in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiagnostic Performance and Histopathological Findings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, the overall diagnostic success rate of ultrasound-guided percutaneous biopsy of renal sinus masses was 90.20% (46/51); among the 46 cases, 5 were benign and 41 were malignant. 5 cases (9.80%) yielded non-diagnostic results due to insufficient tissue or necrosis. In two cases, the initial biopsy yielded only one tissue core, which was insufficient for diagnosis; both were later confirmed by surgery to be UTUC. One lesion exhibited extensive central necrosis with no viable area on CEUS, and was confirmed postoperatively as RCC (Fuhrman grade III). In one case, severe fibrosis in the biopsy specimen precluded diagnosis; laparoscopic biopsy later confirmed a solitary fibrous tumor. One case was complicated by intraoperative bleeding that interfered with sampling; a second CT-guided biopsy confirmed metastatic adenocarcinoma originating from the lung. Univariate logistic regression analysis showed no significant associations between diagnostic success and tumor size (\u0026gt;30 mm vs. \u0026le;30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum, or number of biopsy passes (1\u0026ndash;4) (Table 3). Comprehensive pathological data of the 51 cases are presented in Table 2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComplication Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe overall complication rate of ultrasound-guided percutaneous biopsy of renal sinus masses was 7.84% (4/51), including three cases of perirenal hematoma (15\u0026ndash;20 mm in diameter) and one case of gross hematuria, all classified as Clavien\u0026ndash;Dindo grade I\u0026ndash;II. Details of management and outcomes are as follows:\u003cbr\u003e\u003cstrong\u003eCase 1\u003c/strong\u003e: Immediate postoperative ultrasound revealed a 15 mm hematoma. The patient remained hemodynamically stable and was managed with local compression and extended bed rest (6 hours). The hematoma resolved spontaneously within one week, as confirmed on follow-up ultrasound.\u003cbr\u003e\u003cstrong\u003eCase 2\u003c/strong\u003e: Minor bleeding occurred during the procedure. Thrombin (500 IU) was injected via the coaxial sheath to embolize the needle tract. The patient was observed for 24 hours postoperatively without the need for further intervention.\u003cbr\u003e\u003cstrong\u003eCase 3\u003c/strong\u003e: The patient developed mild flank pain 24 hours post-procedure. Ultrasound confirmed a 20 mm perirenal hematoma. Symptomatic treatment with analgesia and an extended hospital stay (48 hours) was provided. The hematoma resolved completely by one-month follow-up.\u003cbr\u003e\u003cstrong\u003eCase 4 (hematuria)\u003c/strong\u003e: Gross hematuria developed 6 hours after biopsy. The patient was treated with intravenous tranexamic acid and absolute bed rest. Hematuria resolved within 24 hours without evidence of coagulopathy or thrombotic events.\u003c/p\u003e\n\u003cp\u003eNo major complications such as arteriovenous fistula, significant hemorrhage, or nephrectomy were observed. Univariate logistic regression analysis showed no significant associations between complication occurrence and tumor size (\u0026gt;30 mm vs. \u0026le;30 mm), tumor location (upper/middle vs. lower pole), proximity to the renal hilum, number of biopsy passes (1\u0026ndash;4) (Table 4).\u003c/p\u003e\n\u003cp\u003eAll available post-biopsy axial imaging data were retrospectively reviewed to evaluate for delayed complications and needle tract seeding. As of the time of data collection, five patients had no imaging or clinical follow-up. Among the remaining 46 patients, the median imaging follow-up period was 5 years (range: 0.2\u0026ndash;12 years). No imaging findings suggestive of delayed complications or tumor seeding along the biopsy tract were identified.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImpact on Clinical Decision-Making\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBiopsy results altered the treatment strategy in 23.5% (12/51) of patients, including 7.8% (4/51) in whom unnecessary surgery was avoided(Figure 5、Suppl. Fig. 1). Among the 46 patients with available treatment data, 27 underwent surgery alone\u0026mdash;23 underwent radical nephrectomy and 4 underwent partial nephrectomy(Suppl. Fig. 2、Suppl. Fig. 3、Suppl. Fig. 4). One patient received medical, two patients received ablation therapy, one received chemotherapy, and five were managed with active surveillance. Ten patients underwent combination therapy, including chemotherapy plus surgery in seven cases and chemotherapy plus radiotherapy in three (Table 5、Figure 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u0026nbsp;\u003c/strong\u003ePatient and Tumor Characteristics\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"542\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePatients Characteristic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eN=51\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eN\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eMedian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eRange (mean)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e19-85（64.29）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e43.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e56.86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eMaximum Diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eMedian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eRange (mean)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e13-78（30.09）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eLaterality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e52.94\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e47.06\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEnhancement Pattern\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eHomogeneous\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e43.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eHeterogeneous\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e56.86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eRENAL nephrometry score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eLow（4-6）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eModerate（7-9）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e11.76\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eHigh（10-12）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e88.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003ePathological Results\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"536\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDiagnostic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eN\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eBenign\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; Angiomyolipoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e3.92\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eEosinophilic Adenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e3.92\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eSolitary Fibrous Tumor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1.96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eIgG4-related Kidney Disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1.96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003eMalignant\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u0026nbsp;UTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e43.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; RCC, clear cell\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e31.37\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; RCC, papillary\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e3.92\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; RCC, chromophobe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1.96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; Metastatic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e5.88\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 291px;\"\u003e\n \u003cp\u003e\u0026nbsp; Lymphoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e1.96\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote.\u0026mdash;UTUC,\u0026nbsp;upper-tract urothelial carcinoma, RCC,\u0026nbsp;renal cell carcinoma\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u0026nbsp;\u003c/strong\u003eUnivariate Logistic Regression Model for Diagnostic Success Rate\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"539\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter level\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSuccessful Diagnoses / Total\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003eCI\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eMaximum diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026le;30 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e4/33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026gt;30 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e1/18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.43(0.04\u0026ndash;4.12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.64\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eLocation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Upper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e2/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; Mid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e3/32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.26(0.03 - 1.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eLower\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e0/12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.08 (0.00 - 1.97)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eNearness to hilum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; Not near\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e2/31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eNear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e3/20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e2.56（0.39 - 16.78）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.34\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eBiopsy cores (N)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e2/6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e3/19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.38 (0.01 - 0.50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp; 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e0/17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.05 (0.00 - 1.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e0/9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e0.09 (0.00 - 2.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u0026nbsp;\u003c/strong\u003eUnivariate Logistic Regression Model for Complications\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"539\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter level\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 151px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eComplications / Total\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e\u003cstrong\u003e（\u003c/strong\u003e\u003cstrong\u003eCI\u003c/strong\u003e\u003cstrong\u003e）\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eMaximum diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026le;30 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e2/33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026gt;30 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e2/18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e1.94 (0.25\u0026ndash;15.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eLocation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; Upper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e1/12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; Mid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e3/32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e1.14 (0.13 - 10.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eLower\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e0/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e0.54 (0.02 - 6.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eNearness to hilum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; Not near\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e2/31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eNear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e2/20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e0.33（0.02, 3.52）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eBiopsy cores (N)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e1/6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e2/19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e0.59 (0.04 - 5.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.63\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e\u0026nbsp; 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e0/17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e0.10 (0.00 - 3.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0.32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 151px;\"\u003e\n \u003cp\u003e1/9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e0.63(0.03 - 6.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5\u0026nbsp;\u003c/strong\u003eDetails of 12 Cases with Treatment Modification\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"747\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNo.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 161px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePre-biopsy Suspicion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBiopsy Pathology\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 350px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTreatment Change\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eIgG4-related Kidney Disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eRadical nephrectomy \u0026rarr; Medical therapy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eLymphoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eRadical nephrectomy \u0026rarr; Chemotherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eEosinophilic Adenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Active surveillance\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eInflammation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eMedical therapy \u0026rarr; Radical nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eMalignant\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eAngiomyolipoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Active surveillance\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eBenign\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Radical nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Radical nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Radical nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eRadical nephrectomy \u0026rarr; Partial nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eRadical nephrectomy \u0026rarr; Partial nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eEosinophilic Adenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003ePartial nephrectomy \u0026rarr; Active surveillance\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 161px;\"\u003e\n \u003cp\u003eUTUC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRCC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 350px;\"\u003e\n \u003cp\u003eRadical nephrectomy \u0026rarr; Partial nephrectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote.\u0026mdash;UTUC, upper-tract urothelial carcinoma, RCC, renal cell carcinoma\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur retrospective analysis of 51 patients undergoing ultrasound-guided percutaneous renal sinus core needle biopsy shows that this approach achieves a high diagnostic yield while maintaining a favorable safety profile in complex renal masses. According to current European Association of Urology (EAU) guidelines, the diagnostic work-up for suspected UTUC relies on CT urography, ureteroscopic biopsy, and urine cytology\u003csup\u003e[20]\u003c/sup\u003e. Each of these techniques has recognized shortcomings: CT urography lacks sensitivity for small or flat lesions, ureteroscopic biopsy is technically demanding with variable success rates (70\u0026ndash;90%), and urine cytology performs poorly for low-grade disease. Within this context, the 90.2% diagnostic success and low incidence of only minor complications (5.9%) in our series suggest that ultrasound-guided renal sinus biopsy provides a valuable complementary tool, particularly in cases where imaging is inconclusive or ureteroscopic biopsy is unsuccessful, and when histological subtyping is needed to guide systemic therapy.\u003c/p\u003e\n\u003cp\u003eDiagnostic outcomes for renal parenchymal biopsy have been well established, with reported accuracy ranging from 85\u0026ndash;97% and complication rates generally low\u003csup\u003e[21\u0026ndash;30]\u003c/sup\u003e. Core biopsy consistently outperforms fine-needle aspiration\u003csup\u003e[31]\u003c/sup\u003e. In contrast, data specific to renal sinus lesions remain limited. While MRI guidance offers superior soft-tissue contrast and is often recommended for anatomically challenging locations, our findings indicate that ultrasound-guided biopsy achieves a comparable diagnostic accuracy (90.2% vs. 90\u0026ndash;96%)\u003csup\u003e[32]\u003c/sup\u003e. The consistent use of core needles and contrast-enhanced ultrasound in our cohort likely contributed to this performance by enabling precise, real-time targeting while avoiding necrotic or cystic regions. Unlike MRI, ultrasound is widely available, less costly, and simpler to perform, making it more adaptable to routine clinical practice.\u003c/p\u003e\n\u003cp\u003eDespite the anatomical complexity of the renal sinus, including its proximity to major vessels and the ureter, a high diagnostic yield was achieved even in highly complex tumors (RENAL score 10\u0026ndash;12, 88.2%). The few biopsy failures (9.8%) were largely attributable to limited tissue volume or necrosis, indicating that ultrasound guidance remains technically reliable even in challenging cases. The overall complication rate was 7.8%, all Clavien\u0026ndash;Dindo grade I\u0026ndash;II (perirenal hematoma and gross hematuria). All events resolved with conservative management, and no major bleeding, interventions, or tract seeding were observed. These findings are consistent with the reported complication rates for renal parenchymal biopsy (3\u0026ndash;10%). The ability of real-time ultrasound to guide the needle path and avoid major vessels likely contributes to the low incidence of severe hemorrhage.\u003c/p\u003e\n\u003cp\u003eEven so, international guidelines remain cautious about percutaneous biopsy in suspected UTUC, citing risks of tumor seeding and under-sampling, and generally do not recommend it as a first-line diagnostic approach\u003csup\u003e[33]\u003c/sup\u003e. In this context, renal sinus biopsy should be considered an adjunct rather than a replacement for established modalities, and reserved for carefully selected patients in experienced centers. Needle tract seeding has been reported in 0.01\u0026ndash;6% of renal biopsies\u003csup\u003e[13]\u003c/sup\u003e, although the true incidence is likely underestimated in patients who do not undergo surgery\u003csup\u003e[34]\u003c/sup\u003e. In our study, the use of coaxial systems combined with immediate tract ablation, along with standardized follow-up using ultrasound and cross-sectional imaging, revealed no evidence of seeding. Independent review by two radiologists further confirmed the absence of delayed complications. Nevertheless, the median follow-up of five months was relatively short, and late-onset recurrence cannot be excluded. Larger, multicenter studies with longer follow-up will be needed to establish the long-term safety profile of this procedure.\u003c/p\u003e\n\u003cp\u003eRenal biopsy not only establishes a diagnosis but also directly shapes therapeutic decision-making. In our cohort, biopsy results modified management in 23.5% of patients, and 7.8% avoided unnecessary surgery owing to benign pathology. Precise histological subtyping was critical\u0026mdash;particularly distinguishing UTUC (43.1%) from clear cell RCC (31.4%)\u0026mdash;as these entities demand fundamentally different treatment strategies: systemic therapy and ureterectomy for UTUC versus nephron-sparing surgery for RCC\u003csup\u003e[35]\u003c/sup\u003e. Such diagnostic clarity is increasingly important in the era of targeted and immune therapies, where molecular and histological confirmation guide systemic treatment selection. These findings highlight the contribution of ultrasound-guided renal sinus biopsy to personalized management, especially for patients with indeterminate imaging, suspected metastases requiring subtyping, or significant surgical risk.\u003c/p\u003e\n\u003cp\u003eThis study has several limitations. It was a single-center retrospective analysis with a modest sample size, which limits statistical power and may introduce selection bias. Follow-up was incomplete in five patients, and in some cases too short to fully evaluate delayed complications such as tract seeding. Not all cases were confirmed surgically (39 patients underwent resection), raising the possibility of overestimating diagnostic accuracy. All procedures were performed by two highly experienced radiologists, which may restrict generalizability and implies a learning curve that should be characterized in future studies. In addition, no direct comparison was made with CT- or MRI-guided biopsy, limiting conclusions about relative performance. Finally, although no tract seeding was observed during a median follow-up of five years, longer-term multicenter prospective studies will be needed to validate safety and durability.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eUltrasound-guided percutaneous core needle biopsy of renal sinus masses is a safe and effective method that provides essential diagnostic information and supports clinical decision-making. Despite anatomical challenges, its real-time imaging and lack of radiation highlight its value in renal tumor management. With ongoing technological advances, this technique may further optimize patient care pathways.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003eUS\u003c/strong\u003e：ultrasound\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCT\u003c/strong\u003e：computed tomography\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMRI\u003c/strong\u003e：magnetic resonance imaging\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCEUS\u003c/strong\u003e：contrast-enhanced ultrasound\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCI\u003c/strong\u003e：confidence interval\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOR\u003c/strong\u003e：odds ratio\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUTUC:\u003c/strong\u003eupper-tract urothelial carcinoma\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRCC\u003c/strong\u003e：renal cell carcinoma\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval and Consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of Fujian Provincial Hospital.\u003cbr\u003e\u0026nbsp;All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments.\u003cbr\u003e\u0026nbsp;The requirement for informed consent was waived because of the retrospective nature of this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This study was supported by the Fujian Provincial Department of Finance (Grant No. Min Cai Zhi [2024] 881, Project Code: 0060092410).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eL.X. contributed to conceptualization, data curation, formal analysis, investigation, methodology, software, validation, visualization, and prepared the original draft of the manuscript.\u003c/p\u003e\n\u003cp\u003eZ.X.T. contributed to conceptualization, data curation, investigation, and manuscript review and editing.\u003c/p\u003e\n\u003cp\u003eS.M.J. contributed to methodology, validation, and manuscript review and editing.\u003c/p\u003e\n\u003cp\u003eH.Z.L. contributed to methodology, validation, and manuscript review and editing.\u003c/p\u003e\n\u003cp\u003eW.S.S. contributed to conceptualization, funding acquisition, investigation, methodology, project administration, resources, supervision, and writing of both the original draft and the revised manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eL.X. and Z.X.T. contributed equally to this work and are designated as co-first authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors are thankful to Fujian Provincial Hospital and Fujian Medical University for their management of our patient database.\u003c/p\u003e\n\u003cp\u003eThe authors are thankful to Song-Song Wu for helping critically revise the manuscript for important intellectual content and helping collect data and design the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eClark DP. Seize the opportunity: underutilization of fine-needle aspiration biopsy to inform targeted cancer therapy decisions. Cancer. 2009;117:289\u0026ndash;97.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVolpe A, Finelli A, Gill IS, et al. Rationale for percutaneous biopsy and histologic characterisation of renal tumours. Eur Urol. 2012;62:491\u0026ndash;504.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVolpe A, Kachura JR, Geddie WR, et al. Techniques, safety and accuracy of sampling of renal tumors by fine needle aspiration and core biopsy. J Urol. 2007;178:379\u0026ndash;86.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSmaldone MC, Corcoran AT, Uzzo RG. Active surveillance of small renal masses. Nat Rev Urol. 2013;10:266\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMarconi L, Dabestani S, Lam TB, et al. Systematic review and meta-analysis of diagnostic accuracy of percutaneous renal tumour biopsy. 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Clin Genitourin Cancer. 2024;22(2):189\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCaoili EM, Davenport MS. Role of percutaneous needle biopsy for renal masses. Semin Intervent Radiol. 2014;31:20\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBraak SJ, van Melick HHE, Onaca MG, van Heesewijk JPM, van Strijen MJL. 3D cone-beam CT guidance, a novel technique in renal biopsy\u0026ndash;results in 41 patients with suspected renal masses. Eur Radiol. 2012;22(11):2547\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSanchez A, Feldman AS, Hakimi AA. Current management of small renal masses, including patient selection, renal tumor biopsy, active surveillance, and thermal ablation. J Clin Oncol. 2018;36(36):3591\u0026ndash;600.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKim MH. 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J Vasc Interv Radiol. 2013;24(1):90\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoupr\u0026ecirc;t M, Babjuk M, Burger M, Capoun O, Cohen D, Comperat EM, et al. European Association of Urology Guidelines on Upper Urinary Tract Urothelial Carcinoma: 2020 Update. Eur Urol. 2021;79(1):62\u0026ndash;79.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePrince J, Bultman E, Hinshaw L, et al. Patient and tumor characteristics can predict nondiagnostic renal mass biopsy findings. J Urol. 2015;193(6):1899\u0026ndash;904.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePatel HD, Johnson MH, Pierorazio PM, et al. Diagnostic accuracy and risks of biopsy in the diagnosis of a renal mass suspicious for localized renal cell carcinoma: systematic review of the literature. J Urol. 2016;195(5):1340\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLeveridge MJ, Finelli A, Kachura JR, et al. Outcomes of small renal mass needle core biopsy, nondiagnostic percutaneous biopsy, and the role of repeat biopsy. Eur Urol. 2011;60(3):578\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePaterson C, Ghaemi J, Alashkham A, et al. Diagnostic accuracy of image-guided biopsies in small (\u0026lt;\u0026thinsp;4 cm) renal masses with implications for active surveillance: a systematic review of the evidence. Br J Radiol. 2018;91(1090):20170761.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShannon BA, Cohen RJ, de Bruto H, Davies RJ. The value of preoperative needle core biopsy for diagnosing benign lesions among small, incidentally detected renal masses. J Urol. 2008;180(4):1257\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePosielski NM, Bui A, Wells SA, et al. Risk factors for complications and nondiagnostic results following 1,155 consecutive percutaneous core renal mass biopsies. J Urol. 2019;201(6):1080\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeager MJ, Patel U, Anderson CJ, Gonsalves M. Imageguided biopsy of small (\u0026le;\u0026thinsp;4 cm) renal masses: the effect of size and anatomical location on biopsy success rate and complications. Br J Radiol. 2018;91(1085):20170666.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHalverson SJ, Kunju LP, Bhalla R, et al. Accuracy of determining small renal mass management with risk stratified biopsies: confirmation by final pathology. J Urol. 2013;189(2):441\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang R, Wolf JS, Wood DP, Higgins EJ, Hafez KS. Accuracy of percutaneous core biopsy in management of small renal masses. Urology. 2009;73(3):586\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang CS, Choi E, Idrees MT, et al. Percutaneous biopsy of the renal mass: FNA or core needle biopsy? Cancer Cytopathol. 2017;125(6):407\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCazzato RL, De Marini P, Auloge P et al. Diagnostic accuracy and safety of percutaneous MRI-guided biopsy of solid renal masses: single-center results after 4.5 years. EUR RADIOL. 2020; 31 (2).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRizzo M, Cabas P, Pavan N, et al. Needle tract seeding after percutaneous cryoablation of small renal masses; a case series and literature review. Scand J Urol. 2020;54(2):122\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTomiyama N, Yasuhara Y, Nakajima Y, Adachi S, Arai Y, Kusumoto M, et al. CT-Guided Needle Biopsy of Lung Lesions: A Survey of Severe Complication Based on 9783 Biopsies in Japan. Eur J Radiol. 2006;59(1):60\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGupta S. Role of image-guided percutaneous needle biopsy in cancer staging. Semin Roentgenol. 2006;41(2):78\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cancer-imaging","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"caig","sideBox":"Learn more about [Cancer Imaging](https://cancerimagingjournal.biomedcentral.com/)","snPcode":"40644","submissionUrl":"https://submission.nature.com/new-submission/40644/3","title":"Cancer Imaging","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ultrasound-guided biopsy, renal sinus mass, diagnostic accuracy, complication rate, upper-tract urothelial carcinoma","lastPublishedDoi":"10.21203/rs.3.rs-7771586/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7771586/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eRenal sinus lesions present diagnostic challenges due to their complex anatomy and heterogeneous pathology. Reliable tissue acquisition is essential for guiding treatment decisions, yet evidence on the performance of ultrasound (US)-guided biopsy in this setting remains limited.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e\u003cp\u003eWe retrospectively analyzed 51 patients who underwent US-guided percutaneous core needle biopsy of renal sinus masses at a tertiary medical center (2010\u0026ndash;2020). Inclusion criteria were renal sinus masses with indeterminate imaging features. Diagnostic yield, histological results, complication rates (Clavien\u0026ndash;Dindo classification), and subsequent treatment modifications were assessed. Univariate logistic regression was performed to explore factors associated with complications.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eBiopsy achieved a diagnostic yield of 90.2% (46/51). Malignant lesions accounted for 88.2% of cases, most commonly upper-tract urothelial carcinoma of the renal pelvis (43.1%) and clear cell renal cell carcinoma (31.4%). Benign lesions comprised 11.8%. The overall complication rate was 7.8% (4/51), limited to grade I\u0026ndash;II events (perirenal hematoma, hematuria); no major complications or needle tract seeding were observed. Biopsy findings altered treatment in 23.5% of patients, and unnecessary surgery was avoided in 7.8%. Tumor size, location, and number of needle passes were not significantly associated with complications (all \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eUS-guided percutaneous core biopsy of renal sinus masses is a safe and effective diagnostic approach, providing high tissue yield with low morbidity. By enabling accurate diagnosis and reducing overtreatment, this technique represents a valuable tool in the management of complex renal tumors.\u003c/p\u003e","manuscriptTitle":"Ultrasound-Guided Percutaneous Core Biopsy of Renal Sinus Masses: Diagnostic Yield, Safety, and Clinical Impact","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-23 16:10:07","doi":"10.21203/rs.3.rs-7771586/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-13T15:53:21+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-31T17:11:33+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-23T21:37:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"239964524150252204517446688304380347090","date":"2025-10-23T03:42:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"286292196524123946582792031207733621322","date":"2025-10-22T20:23:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"245329545644684903844471319318694613497","date":"2025-10-13T09:36:14+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-10T05:36:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"58563135364263396697151535712900959909","date":"2025-10-09T19:07:16+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-09T18:55:37+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-09T12:50:51+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-08T11:55:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Cancer Imaging","date":"2025-10-03T08:11:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cancer-imaging","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"caig","sideBox":"Learn more about [Cancer Imaging](https://cancerimagingjournal.biomedcentral.com/)","snPcode":"40644","submissionUrl":"https://submission.nature.com/new-submission/40644/3","title":"Cancer Imaging","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4a1ee151-94c3-49b1-ae4d-c3a63cbb6ab5","owner":[],"postedDate":"October 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-29T16:04:12+00:00","versionOfRecord":{"articleIdentity":"rs-7771586","link":"https://doi.org/10.1186/s40644-025-00983-w","journal":{"identity":"cancer-imaging","isVorOnly":false,"title":"Cancer Imaging"},"publishedOn":"2025-12-24 15:57:34","publishedOnDateReadable":"December 24th, 2025"},"versionCreatedAt":"2025-10-23 16:10:07","video":"","vorDoi":"10.1186/s40644-025-00983-w","vorDoiUrl":"https://doi.org/10.1186/s40644-025-00983-w","workflowStages":[]},"version":"v1","identity":"rs-7771586","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7771586","identity":"rs-7771586","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}