The discordance between preoperative and postoperative pathological diagnoses in chondrosarcoma: from a specialized sarcoma treatment center in Japan 

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Although accurate preoperative assessment of chondrosarcoma tumor grade remains difficult, evaluating discordance between preoperative and postoperative diagnoses is important for selecting an appropriate surgical procedure. Methods. We retrospectively reviewed 60 patients with chondrosarcoma who visited Nagoya University Hospital and had both preoperative and postoperative pathological diagnoses. Factors associated with the occurrence of second biopsy and discordance between preoperative and postoperative pathological diagnoses were assessed. Results. A second biopsy was performed in 11 of 60 patients (18.3%). Preoperative first pathological diagnosis was associated with the occurrence of second biopsy ( p < 0.001). Discordance between preoperative and postoperative diagnoses was observed in 25 of 60 patients (41.7%), and the preoperative final pathological grade was underestimated in all but one patient with postoperative grades 1, 2, and 3 chondrosarcomas. Surgery, preoperative final pathological diagnosis, and postoperative pathological diagnosis were found to influence the discordance between the preoperative and postoperative pathological grades ( p = 0.029, p = 0.025, and p = 0.005, respectively). Conclusions. In approximately 40% of patients, preoperative grade of chondrosarcoma was underestimated. Predicting postoperative pathological changes before surgery remains difficult; therefore, careful consideration of the surgical procedure is required for each patient by integrating imaging findings with preoperative pathological results. chondrosarcoma biopsy pathology grade Figures Figure 1 BACKGROUND Chondrosarcoma is a malignant bone neoplasm that arises either de novo in elderly people or from a preexisting benign cartilaginous tumor in patients with Ollier disease, Maffucci syndrome, or osteochondrosis. Central chondrosarcoma includes de novo tumors and those arising from Ollier disease and Maffucci syndrome, whereas chondrosarcoma arising from osteochondrosis is classified as secondary peripheral chondrosarcoma [ 1 , 2 ]. Chondrosarcomas typically arise in long bones, the pelvis, and the trunk. Dedifferentiated chondrosarcoma is a high-grade subtype characterized by a bimorphic histological appearance, consisting of a conventional chondrosarcoma component and an abrupt transition to a high-grade, noncartilaginous sarcoma. Previous reports showed that 9.5–59.9% of patients with chondrosarcoma had discordance between histological grade on biopsy and resection [ 3 – 6 ]. A previous report showed that the discordance between preoperative and postoperative pathological diagnoses was much higher in pelvic chondrosarcoma than in long-bone chondrosarcoma [ 5 ]. Because recent studies have shown that curettage is safe and effective in selected patients with low-grade chondrosarcoma of the long bones [ 7 – 10 ], accurate preoperative pathological diagnosis of chondrosarcoma is of increasing importance. This study aimed to identify discordance between preoperative and postoperative diagnoses of chondrosarcoma and the factors associated with this discordance in patients with chondrosarcoma. PATIENTS AND METHODS Patients We retrospectively reviewed 60 consecutive patients with chondrosarcoma who visited Nagoya University Hospital between May 2003 and July 2024 and had preoperative and postoperative pathological specimens available. Patients with mesenchymal or clear cell chondrosarcoma were excluded from this study. This study was approved by the Ethics Committee of the Nagoya University Graduate School and School of Medicine (Nagoya, Japan) in November 2025 (registration number: 2025 − 0365). A waiver of informed consent was obtained from the institutional review board. The patient demographics and tumor characteristics are summarized in Table 1 . There were 38 men and 22 women with a median age of 55.5 (12–85) years. The primary tumor sites were the rib (20 patients), pelvis (16 patients), femur (16 patients), humerus (3 patients), tibia (2 patients), and calcaneus/scapula/sternum (one patient each). The median tumor size was 7.9 (range 2.0–32.6) cm. There were 4 patients with Ollier disease/Maffucci syndrome (6.7%) and 1 with osteochondrosis (1.7%). Preoperative final pathological diagnoses were enchondroma in 2 patients, enchondroma or Grade 1 in 3, Grade 1 in 24, Grade 2 in 24, Grade 3 in 2, malignant tumors other than chondrosarcoma in 4, and difficult to diagnose in 1, whereas postoperative diagnoses were Grade 1 in 16, Grade 2 in 30, Grade 3 in 6, and dedifferentiated in 8. Positron Emission Tomography-Computed Tomography (PET/CT) was performed before the first biopsy in 2 patients and after the first biopsy but before the second biopsy in 1 patient. All patients underwent surgical treatment, including curettage in 6 (10.0%) and wide resection in 54 (90.0%). Curettage was performed only in patients with a final preoperative and postoperative pathological diagnoses of Grade 1, including 2 patients with pelvic tumors and 4 with tumors of the extremity. The median follow-up period was 47.7 (range 1.6–187.0) months. Methods Discordance between preoperative and postoperative diagnoses was defined as a difference in pathological diagnosis or tumor grade between preoperative and postoperative pathological diagnoses. If the preoperative final pathological diagnosis was enchondroma or Grade 1 chondrosarcoma, and the postoperative diagnosis was Grade 1 chondrosarcoma, this was considered no discordance. Final biopsy was defined as the pathological result of the first biopsy if only the first biopsy was performed, or as the pathological result of the second biopsy if a second biopsy was performed. Clinical factors, including sex, age (continuous), site (extremity, trunk and pelvis), size (continuous), preexisting disease (osteochondrosis, Ollier disease/Maffucci syndrome, or none), first biopsy method (needle, open, or unknown), surgery (curettage and wide resection), preoperative first pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma, and difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3, and dedifferentiated) were analyzed for the occurrence of second biopsy. Clinical factors, including sex, age (continuous), site (extremity, trunk and pelvis), size (continuous), preexisting disease (osteochondrosis, Ollier disease/Maffucci syndrome, or none), final biopsy method (needle, open, or unknown), surgery (curettage and wide resection), preoperative final pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma, and difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3, and dedifferentiated) were analyzed for discordance between preoperative and postoperative diagnoses. Preoperative pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma that are difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3 and dedifferentiated) were analyzed for overall survival (OS). Statistics Clinical data were collected from patients’ clinical records and our database. For continuous data, the Mann–Whitney U test was used to compare paired samples. The chi-square test was used to analyze the correlation between various clinical factors. OS was calculated using the Kaplan-Meier product limit method. Preoperative first pathological diagnosis, preoperative final pathological diagnosis, and postoperative pathological diagnosis were analyzed for OS using log-rank test. Statistical significance was set at p < 0.05. RESULTS Second biopsies Second biopsies were performed in 11 of 60 patients (18.3%) (Table 1 ). No patients underwent a third biopsy. Preoperative and postoperative pathological diagnoses in the 11 patients who underwent second biopsies are shown in Table 2 . Three of the 5 patients whose first biopsy was difficult to diagnose were diagnosed with chondrosarcoma at the second biopsy, and the remaining 2 patients were diagnosed with enchondroma or Grade 1 and a malignant tumor other than chondrosarcoma. Of the 5 patients diagnosed with cartilaginous tumors at the first biopsy, 4 had an increase, and one had no change in grade at the second biopsy. Preoperative first pathological diagnosis was associated with the occurrence of second biopsy ( p < 0.001) ( Table 4 ). A second biopsy was frequently performed in patients whose preoperative first pathological diagnosis was malignant tumors other than chondrosarcoma (1 of 3 patients [33.3%]), enchondroma (2 of 4 patients [50%]), enchondroma or Grade 1 (2 of 4 patients [50%]), and difficult to diagnose (5 of 6 patients [83.3%]). Table 2 Preoperative and postoperative pathological diagnosis in patients undergoing repeated biopsies Tumor sites First biopsy Second biopsy Postoperative pathological diagnosis Preoperative first pathological diagnosis (Biopsy method) Preoperative second pathological diagnosis (Biopsy method) Pelvis Enchondroma (Open) Grade 1 (Open) Grade 1 Rib Enchondroma (Open) Grade 1 (Open) Grade 3 Pelvis Enchondroma or Grade 1 (Needle) Grade 2 (Open) Grade 2 Rib Enchondroma or Grade 1 (Needle) Grade 2 (Open) Grade 2 Rib Grade 1 (Needle) Grade 1 (Open) Grade 2 Pelvis Malignant tumors other than chondrosarcoma (Needle) Malignant tumors other than chondrosarcoma (Open) Dedifferentiated Femur Difficult to diagnose (Needle) Enchondroma or Grade 1 (Needle) Grade 1 Pelvis Difficult to diagnose (Needle) Grade 1 (Needle) Grade 1 Pelvis Difficult to diagnose (Needle) Grade 2 (Needle) Grade 2 Pelvis Difficult to diagnose (Needle) Grade 2 (Open) Grade 2 Femur Difficult to diagnose (Needle) Malignant tumors other than chondrosarcoma (Open) Dedifferentiated no.; number Discordance between preoperative and postoperative pathological diagnoses Discordance between preoperative and postoperative diagnoses was observed in 32 of 60 patients (53.3%) at first biopsy (Table 3 -A) and in 25 of 60 (41.7%) at final biopsy (Table 3 -B). When dedifferentiated chondrosarcoma was excluded, discordance between preoperative and postoperative diagnoses was observed in 24 of 52 patients (46.2%) at first biopsy and 17 of 52 (32.7%) at final biopsy. The preoperative final pathological grade was underestimated in all but one patient with postoperative Grade 1, 2, and 3 chondrosarcomas (Table 3 -B). Surgery, preoperative final pathological diagnosis, and postoperative pathological diagnosis were associated with discordance between preoperative and postoperative pathological grades ( p = 0.029, p = 0.025, and p = 0.005, respectively). ( Table 5 ). No discordance between preoperative and postoperative pathological diagnoses was observed in the 6 patients who underwent curettage. There were relatively few pathological discordances in patients with postoperative Grade 1 (1 of 16 [6%]) and Grade 2 chondrosarcoma (11 of 30 [36.7%]), but many pathological discordances were observed in postoperative Grade 3 (5 of 6 [83%]) and dedifferentiated chondrosarcoma (8 of 8 [100%]). Overall Survival Preoperative pathological diagnosis at the first and final biopsies did not correlate with OS ( p = 0.622 and p = 0.744, respectively) ( Figure 1-A and 1-B ), whereas postoperative pathological diagnosis did ( p = 0.009) ( Figure 1-C ). DISCUSSION Although several studies have reported discordance between preoperative and postoperative pathological diagnoses in chondrosarcoma [ 3 – 6 ], few have examined second biopsy. Therefore, this provides additional insight into this area. Preoperative first pathological diagnosis was associated with the occurrence of second biopsy in this study. A second biopsy was frequently performed in patients whose preoperative first pathological diagnosis was malignant tumors other than chondrosarcoma (1 of 3 patients [33.3%]), enchondroma (2 of 4 patients [50%]), enchondroma or Grade 1 (2 of 4 patients [50%]), and difficult to diagnose (5 of 6 patients [83.3%]). A second biopsy may be performed in patients whose treatment plan cannot be determined based on the first biopsy results or when there is discordance between clinical findings/imaging findings and first pathological diagnosis. The first biopsy method was not associated with the occurrence of second biopsy in this study. First biopsy was performed by needle biopsy in 34 patients (56.7%) and open biopsy in 24 (40.0%), and the biopsy method was unknown in 2 (3.3%). Second biopsies were performed in 9 patients (81.8%) whose first biopsy was needle biopsy and in 2 patients (18.2%) whose first biopsy was open biopsy; this may be due to the smaller sample volume obtained with needle biopsy. Of the 11 patients who underwent a second biopsy, 3 (27.3%) underwent needle biopsy and 8 (72.7%) underwent open biopsy, suggesting that the biopsy method was changed for the second biopsy. If technically possible, open biopsy may be considered at the first biopsy to reduce the likelihood of requiring a second biopsy; however, the biopsy method should be carefully determined based on tumor location. In this study, the median tumor size was 7.9 (2.0–32.6) cm, and the optimal site for tissue sampling in chondrosarcoma remains a matter of debate. Although there are few reports on the use of new imaging methods in cartilaginous tumor biopsy, the following studies describe new diagnostic imaging methods to distinguish between benign and malignant cartilaginous tumors. Jesus‑Garcia et al. reported that the standardized uptake value (SUV) max between 2.0 and 2.2 may represent a threshold range distinguishing chondroma from chondrosarcoma and may be valuable, among others diagnostic methods, in guiding treatment decisions for patients with cartilaginous lesions of the long bones using PET/CT [ 11 ]. On the other hand, Douis et al. showed that diffusion-weighted magnetic resonance imaging (MRI) cannot differentiate between enchondromas and chondrosarcoma and does not aid in distinguishing low-grade chondroid tumors from high-grade chondrosarcoma [ 12 ]. Detection of IDH1/2 or GNAS circulating tumor DNA has been reported to be more accurate than pathology for identifying high-grade chondrosarcomas and is associated with poor prognosis [ 13 , 14 ]. This approach is expected to complement current standard diagnostic protocols. The diagnostic accuracy of biopsy in patients with bone tumors has been reported to be > 90% [ 15 – 18 ]. In this study, discordance between preoperative and postoperative diagnoses was observed in 25 of 60 patients (41.7%) at final biopsy, which is consistent with previous reports of 9.5–59.9% [ 3 – 6 ] and highlights the diagnostic challenges of chondrosarcoma by biopsy. Discordance between preoperative and postoperative diagnoses was observed in 32 of 60 patients (53.3%) at first biopsy, which decreased to 25 of 60 (41.7%) at final biopsy, suggesting that second biopsy may have value in preoperative pathological diagnosis. A previous report showed that discordance between preoperative and postoperative pathological diagnoses was much higher in pelvic chondrosarcoma than in long-bone chondrosarcoma (64.1% [25 of 39] in the pelvis versus 17.5% [7 of 40] in long-bone)[ 5 ]. In this study, the discordance between preoperative and postoperative pathological diagnoses was 37.5% [6 of 16] in the pelvis and 43.5% [10 of 23] in the extremities, and no such trend was observed. Preoperative final and postoperative pathological diagnoses were associated with discordance between preoperative and postoperative pathological diagnoses in this study. Of the 24 patients whose preoperative final pathology was Grade 1, 13 patients (54.2%) had the same diagnosis postoperatively, 9 patients (37.5%) were diagnosed with postoperative Grade 2, 1 patient (4.2%) was diagnosed with postoperative Grade 3, and the remaining patient (4.2%) was diagnosed with postoperative dedifferentiated chondrosarcoma. Of the 24 patients whose preoperative final pathology was Grade 2, 19 patients (79.2%) had the same diagnosis postoperatively, 2 patients (8.3%) were diagnosed with postoperative Grade 3, and 3 patients (12.5%) were diagnosed with postoperative dedifferentiated chondrosarcoma. Of the 2 patients whose preoperative final pathology was Grade 3, 1 patient (50.0%) had the same diagnosis postoperatively, and the remaining patient (50.0%) was diagnosed with postoperative Grade 2. These results indicate that Grade 2 may be more reliable than Grade 1 for the final preoperative pathological diagnosis; however, definitive conclusions regarding Grade 3 are limited because few patients were diagnosed preoperatively. This study targeted patients with postoperative pathological diagnoses of conventional or dedifferentiated chondrosarcoma, and it is therefore expected that discordance would be observed in the final preoperative diagnoses of enchondroma or malignant tumors other than chondrosarcoma. Preoperative diagnosis of dedifferentiated chondrosarcoma is especially challenging. A previous report showed that discordance between preoperative and postoperative diagnoses was observed in 63.6% [7 of 11][ 3 ]. Discordance between preoperative and postoperative diagnoses was observed in 100% [8 of 8] in this study. Among the 8 patients, the preoperative final pathological diagnosis was Grade 1 in 1 patient, Grade 2 in 3, and malignant tumors other than chondrosarcoma in 4. The pathological diagnosis of dedifferentiated chondrosarcoma depends largely on whether prededifferentiated or dedifferentiated tissue is collected. Patients whose final preoperative pathological diagnosis was Grade 1 or Grade 2 likely had prededifferentiated tissue collected, whereas patients with malignant tumors other than chondrosarcoma likely had dedifferentiated tissue collected. Four patients diagnosed with malignant tumors other than chondrosarcoma included osteosarcoma in 2 patients, osteosarcoma or undifferentiated pleomorphic sarcoma (UPS) in 1, and malignant neoplasm in 1. Sopta et al. showed that in 25 patients with dedifferentiated chondrosarcoma, classification of the high-grade components based on immunohistochemical analyses identified UPS in 18 patients, osteosarcoma in 4, fibrosarcoma in 2, and rhabdomyosarcoma in 1 [ 19 ]. They emphasized that the complex morphological and phenotypical presentation of dedifferentiated chondrosarcoma requires precise biopsy technique, acquisition of a greater number of specimens for pathohistological verification, and application of advanced pathological techniques in tissue analysis. Imaging is also important for accurately identifying dedifferentiated and prededifferentiated areas. A previous report showed that dedifferentiation within chondrosarcoma may be identified on T2-weighted MRI as areas of reduced signal intensity, and these areas should be preferred biopsy sites [ 20 ]. Another study reported that the optimal SUV max cutoff was 7.7 for differentiating intermediate/high-grade from dedifferentiated chondrosarcoma (sensitivity 0.92, specificity 0.9) [ 21 ]. These findings suggest that MRI and PET/CT may be useful for identifying dedifferentiated and prededifferentiated areas before biopsy. However, some patients have minimal or small dedifferentiated components [ 22 ], and spatial caution is required in such cases. Histological grade is a well-known prognostic factor in chondrosarcoma [ 23 , 24 ]. In this study, preoperative pathological diagnosis at the first and final biopsies did not correlate with OS, suggesting that the preoperative pathological diagnosis of biopsy specimens does not accurately reflect prognosis. In contrast, postoperative pathological diagnosis correlated with prognosis. These findings indicate that the grade determined by preoperative pathological evaluation does not accurately reflect tumor prognosis, and caution is required when using it to guide treatment strategies. Atypical cartilaginous tumors are defined as low-grade intracompartmental appendicular tumors that allow intralesional resection with or without local adjuvant therapy [ 7 – 10 ]. In this study, in addition to 4 patients with long bone tumors, curettage was also performed in 2 patients with pelvic tumors in whom significant functional impairment due to wide dissection was expected. Surgery was associated with discordance between preoperative and postoperative pathological grades, and no discordance was observed in any of the 6 patients who underwent curettage. In cases involving long bones, lesion curettage may have been performed in more carefully selected cases. Distinguishing between low-grade and high-grade chondrosarcoma remains challenging, and preoperative evaluation should be performed using a multidisciplinary approach, including pathology and radiology. Previous systematic reviews have shown that loss of entrapped fatty marrow, bone marrow edema, cortical breakthrough, or extraosseous soft tissue expansion is more frequently observed in high-grade chondrosarcoma than in atypical cartilaginous tumors [ 25 , 26 ]. This study has some limitations. First, this was a single-center study, and the results may be difficult to extrapolate to other centers; however, the discordance rate between preoperative and postoperative diagnoses was similar to that reported previously [ 3 , 4 ]. Second, the small number of patients may have limited the analysis. Future large-scale, multicenter studies may provide additional insights. Finally, this study included patients over a long period (approximately 20 years), and advances in imaging, such as PET/CT, may have influenced the biopsy methods. In this study, PET/CT was performed before biopsy in only 3 patients, and its usefulness remains controversial. CONCLUSIONS Overall, this study highlights the discordance between preoperative and postoperative diagnoses. Discordance was observed in 41.7% of cases based on preoperative final pathological diagnosis and was more common in patients with high-grade chondrosarcoma on postoperative pathology. Predicting postoperative pathological changes before surgery remains difficult, and careful consideration of the surgical procedure is required for each patient by integrating imaging findings with preoperative pathological results. Abbreviations PET/CT Positron Emission Tomography-Computed Tomography OS Overall Survival SUV Standardized Uptake Value MRI Magnetic Resonance Imaging UPS Undifferentiated Pleomorphic Sarcoma Declarations CLINICAL TRIAL NUMBER Clinical trial number: not applicable. Ethics approval and consent to participate This study was conducted in accordance with the principles of the Declaration of Helsinki. This study was approved by the Ethics Committee of the Nagoya University Graduate School and School of Medicine (Nagoya, Japan) in November 2025 (registration number: 2025-0365). Consent for publication Not applicable. Availability of data and materials All data generated or analyzed during this study are included in this published article. Competing interests The authors declare that they have no competing interests. Funding One author (HU) received research funding from the Ministry of Education, Culture, Sports, Science, and Technology of Japan [Grant-in-Aid 23K08696 for Scientific Research (C)]. Authors’ contributions HU designed and drafted the manuscript, and developed the concept. HU, KK, and SI revised the manuscript and supervised the study. HU, KI, TS, HK, TF, and YN provided the treatment for chondrosarcoma. All the authors have read and approved the final version of this manuscript. Author details 1 Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan 2 Department of Orthopedic Surgery, Nagoya University Hospital, Nagoya, Japan 3 Department of Rehabilitation Medicine, Nagoya University Hospital, Nagoya, Japan 4 Department of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan References Sharif B, Lindsay D, Saifuddin A. The role of imaging in differentiating low-grade and high-grade central chondral tumours. Eur J Radiol. 2021;137:109579. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9324197","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":635281539,"identity":"f0f2bd1c-0003-4ccf-af2f-55ff0099b82f","order_by":0,"name":"Hiroshi Urakawa","email":"data:image/png;base64,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","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":true,"prefix":"","firstName":"Hiroshi","middleName":"","lastName":"Urakawa","suffix":""},{"id":635281543,"identity":"b89005c5-10aa-4808-8c64-7e3d9fdf6971","order_by":1,"name":"Kunihiro Ikuta","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kunihiro","middleName":"","lastName":"Ikuta","suffix":""},{"id":635281544,"identity":"efe6cd24-76f9-47f5-9fb6-d8af2df5bf08","order_by":2,"name":"Tomohisa Sakai","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tomohisa","middleName":"","lastName":"Sakai","suffix":""},{"id":635281545,"identity":"49d4334e-82cc-4918-b1a0-1e8996615835","order_by":3,"name":"Hiroshi Koike","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hiroshi","middleName":"","lastName":"Koike","suffix":""},{"id":635281546,"identity":"9a647723-91d4-40a8-95fa-e6f343106dfe","order_by":4,"name":"Takeo Fujito","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Takeo","middleName":"","lastName":"Fujito","suffix":""},{"id":635281548,"identity":"fa8231d4-e4ac-4ed1-8570-d07489d39791","order_by":5,"name":"Yoshihiro Nishida","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yoshihiro","middleName":"","lastName":"Nishida","suffix":""},{"id":635281549,"identity":"8582c2c3-4100-4193-a1b6-d589792474cf","order_by":6,"name":"Kennosuke Karube","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kennosuke","middleName":"","lastName":"Karube","suffix":""},{"id":635281559,"identity":"9f1568fd-25d3-4ff8-8e2b-fb1c8fbf3ac6","order_by":7,"name":"Shiro Imagama","email":"","orcid":"","institution":"Nagoya University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shiro","middleName":"","lastName":"Imagama","suffix":""}],"badges":[],"createdAt":"2026-04-05 05:24:03","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9324197/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9324197/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108945896,"identity":"f60cf3b7-4171-455d-a0b0-ebb6829aadb0","added_by":"auto","created_at":"2026-05-11 06:18:24","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":379575,"visible":true,"origin":"","legend":"\u003cp\u003eOverall survival curve using Kaplan-Meier product limit methods according to preoperative first pathological diagnoses (\u003cstrong\u003eA\u003c/strong\u003e), preoperative final pathological diagnoses (\u003cstrong\u003eB\u003c/strong\u003e), and postoperative pathological diagnoses (\u003cstrong\u003eC\u003c/strong\u003e).\u003c/p\u003e","description":"","filename":"Figure1A.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9324197/v1/a32fa390f241751a822ec878.jpg"},{"id":108945926,"identity":"9959f184-02c5-4e0c-bdcb-ddb549f29656","added_by":"auto","created_at":"2026-05-11 06:18:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":613503,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9324197/v1/297c82d5-4d25-4696-8efc-f9ff4bbf05ff.pdf"},{"id":108945895,"identity":"715f2269-b8f1-4b19-b42e-a96aa571c103","added_by":"auto","created_at":"2026-05-11 06:18:24","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":28707,"visible":true,"origin":"","legend":"","description":"","filename":"Table1345.docx","url":"https://assets-eu.researchsquare.com/files/rs-9324197/v1/e7a1e4399727622c28c9d5e5.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The discordance between preoperative and postoperative pathological diagnoses in chondrosarcoma: from a specialized sarcoma treatment center in Japan ","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eChondrosarcoma is a malignant bone neoplasm that arises either \u003cem\u003ede novo\u003c/em\u003e in elderly people or from a preexisting benign cartilaginous tumor in patients with Ollier disease, Maffucci syndrome, or osteochondrosis. Central chondrosarcoma includes \u003cem\u003ede novo\u003c/em\u003e tumors and those arising from Ollier disease and Maffucci syndrome, whereas chondrosarcoma arising from osteochondrosis is classified as secondary peripheral chondrosarcoma [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Chondrosarcomas typically arise in long bones, the pelvis, and the trunk. Dedifferentiated chondrosarcoma is a high-grade subtype characterized by a bimorphic histological appearance, consisting of a conventional chondrosarcoma component and an abrupt transition to a high-grade, noncartilaginous sarcoma.\u003c/p\u003e \u003cp\u003ePrevious reports showed that 9.5\u0026ndash;59.9% of patients with chondrosarcoma had discordance between histological grade on biopsy and resection [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. A previous report showed that the discordance between preoperative and postoperative pathological diagnoses was much higher in pelvic chondrosarcoma than in long-bone chondrosarcoma [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Because recent studies have shown that curettage is safe and effective in selected patients with low-grade chondrosarcoma of the long bones [\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], accurate preoperative pathological diagnosis of chondrosarcoma is of increasing importance.\u003c/p\u003e \u003cp\u003eThis study aimed to identify discordance between preoperative and postoperative diagnoses of chondrosarcoma and the factors associated with this discordance in patients with chondrosarcoma.\u003c/p\u003e"},{"header":"PATIENTS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003eWe retrospectively reviewed 60 consecutive patients with chondrosarcoma who visited Nagoya University Hospital between May 2003 and July 2024 and had preoperative and postoperative pathological specimens available. Patients with mesenchymal or clear cell chondrosarcoma were excluded from this study. This study was approved by the Ethics Committee of the Nagoya University Graduate School and School of Medicine (Nagoya, Japan) in November 2025 (registration number: 2025\u0026thinsp;\u0026minus;\u0026thinsp;0365). A waiver of informed consent was obtained from the institutional review board.\u003c/p\u003e \u003cp\u003eThe patient demographics and tumor characteristics are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. There were 38 men and 22 women with a median age of 55.5 (12\u0026ndash;85) years. The primary tumor sites were the rib (20 patients), pelvis (16 patients), femur (16 patients), humerus (3 patients), tibia (2 patients), and calcaneus/scapula/sternum (one patient each). The median tumor size was 7.9 (range 2.0\u0026ndash;32.6) cm. There were 4 patients with Ollier disease/Maffucci syndrome (6.7%) and 1 with osteochondrosis (1.7%). Preoperative final pathological diagnoses were enchondroma in 2 patients, enchondroma or Grade 1 in 3, Grade 1 in 24, Grade 2 in 24, Grade 3 in 2, malignant tumors other than chondrosarcoma in 4, and difficult to diagnose in 1, whereas postoperative diagnoses were Grade 1 in 16, Grade 2 in 30, Grade 3 in 6, and dedifferentiated in 8. Positron Emission Tomography-Computed Tomography (PET/CT) was performed before the first biopsy in 2 patients and after the first biopsy but before the second biopsy in 1 patient.\u003c/p\u003e \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003eAll patients underwent surgical treatment, including curettage in 6 (10.0%) and wide resection in 54 (90.0%). Curettage was performed only in patients with a final preoperative and postoperative pathological diagnoses of Grade 1, including 2 patients with pelvic tumors and 4 with tumors of the extremity. The median follow-up period was 47.7 (range 1.6\u0026ndash;187.0) months.\u003c/div\u003e\n\u003c/div\u003e\n\u003ch3\u003eMethods\u003c/h3\u003e\n\u003cp\u003eDiscordance between preoperative and postoperative diagnoses was defined as a difference in pathological diagnosis or tumor grade between preoperative and postoperative pathological diagnoses. If the preoperative final pathological diagnosis was enchondroma or Grade 1 chondrosarcoma, and the postoperative diagnosis was Grade 1 chondrosarcoma, this was considered no discordance. Final biopsy was defined as the pathological result of the first biopsy if only the first biopsy was performed, or as the pathological result of the second biopsy if a second biopsy was performed.\u003c/p\u003e \u003cp\u003eClinical factors, including sex, age (continuous), site (extremity, trunk and pelvis), size (continuous), preexisting disease (osteochondrosis, Ollier disease/Maffucci syndrome, or none), first biopsy method (needle, open, or unknown), surgery (curettage and wide resection), preoperative first pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma, and difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3, and dedifferentiated) were analyzed for the occurrence of second biopsy. Clinical factors, including sex, age (continuous), site (extremity, trunk and pelvis), size (continuous), preexisting disease (osteochondrosis, Ollier disease/Maffucci syndrome, or none), final biopsy method (needle, open, or unknown), surgery (curettage and wide resection), preoperative final pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma, and difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3, and dedifferentiated) were analyzed for discordance between preoperative and postoperative diagnoses.\u003c/p\u003e \u003cp\u003ePreoperative pathological diagnosis (enchondroma, enchondroma or Grade 1, Grade 1, Grade 2, Grade 3, malignant tumors other than chondrosarcoma that are difficult to diagnose) and postoperative pathological diagnosis (Grade 1, Grade 2, Grade 3 and dedifferentiated) were analyzed for overall survival (OS).\u003c/p\u003e\n\u003ch3\u003eStatistics\u003c/h3\u003e\n\u003cp\u003eClinical data were collected from patients\u0026rsquo; clinical records and our database. For continuous data, the Mann\u0026ndash;Whitney U test was used to compare paired samples. The chi-square test was used to analyze the correlation between various clinical factors. OS was calculated using the Kaplan-Meier product limit method. Preoperative first pathological diagnosis, preoperative final pathological diagnosis, and postoperative pathological diagnosis were analyzed for OS using log-rank test. Statistical significance was set at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eSecond biopsies\u003c/h2\u003e \u003cp\u003eSecond biopsies were performed in 11 of 60 patients (18.3%) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). No patients underwent a third biopsy. Preoperative and postoperative pathological diagnoses in the 11 patients who underwent second biopsies are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Three of the 5 patients whose first biopsy was difficult to diagnose were diagnosed with chondrosarcoma at the second biopsy, and the remaining 2 patients were diagnosed with enchondroma or Grade 1 and a malignant tumor other than chondrosarcoma. Of the 5 patients diagnosed with cartilaginous tumors at the first biopsy, 4 had an increase, and one had no change in grade at the second biopsy. Preoperative first pathological diagnosis was associated with the occurrence of second biopsy (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (\u003cb\u003eTable\u0026nbsp;4\u003c/b\u003e). A second biopsy was frequently performed in patients whose preoperative first pathological diagnosis was malignant tumors other than chondrosarcoma (1 of 3 patients [33.3%]), enchondroma (2 of 4 patients [50%]), enchondroma or Grade 1 (2 of 4 patients [50%]), and difficult to diagnose (5 of 6 patients [83.3%]).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePreoperative and postoperative pathological diagnosis in patients undergoing repeated biopsies\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTumor sites\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFirst biopsy\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSecond biopsy\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePostoperative pathological diagnosis\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePreoperative first pathological diagnosis (Biopsy method)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePreoperative second pathological diagnosis (Biopsy method)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEnchondroma (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 1 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRib\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEnchondroma (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 1 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEnchondroma or Grade 1 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 2 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRib\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEnchondroma or Grade 1 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 2 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRib\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGrade 1 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 1 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMalignant tumors other than chondrosarcoma (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMalignant tumors other than chondrosarcoma (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDedifferentiated\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemur\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDifficult to diagnose (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eEnchondroma or Grade 1 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDifficult to diagnose (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 1 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDifficult to diagnose (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 2 (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDifficult to diagnose (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade 2 (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade 2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemur\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDifficult to diagnose (Needle)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMalignant tumors other than chondrosarcoma (Open)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDedifferentiated\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eno.; number\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDiscordance between preoperative and postoperative pathological diagnoses\u003c/h2\u003e \u003cp\u003eDiscordance between preoperative and postoperative diagnoses was observed in 32 of 60 patients (53.3%) at first biopsy (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e3\u003c/span\u003e-A) and in 25 of 60 (41.7%) at final biopsy (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e3\u003c/span\u003e-B). When dedifferentiated chondrosarcoma was excluded, discordance between preoperative and postoperative diagnoses was observed in 24 of 52 patients (46.2%) at first biopsy and 17 of 52 (32.7%) at final biopsy. The preoperative final pathological grade was underestimated in all but one patient with postoperative Grade 1, 2, and 3 chondrosarcomas (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e3\u003c/span\u003e-B). Surgery, preoperative final pathological diagnosis, and postoperative pathological diagnosis were associated with discordance between preoperative and postoperative pathological grades (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.029, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.025, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005, respectively). (\u003cb\u003eTable\u0026nbsp;5\u003c/b\u003e). No discordance between preoperative and postoperative pathological diagnoses was observed in the 6 patients who underwent curettage. There were relatively few pathological discordances in patients with postoperative Grade 1 (1 of 16 [6%]) and Grade 2 chondrosarcoma (11 of 30 [36.7%]), but many pathological discordances were observed in postoperative Grade 3 (5 of 6 [83%]) and dedifferentiated chondrosarcoma (8 of 8 [100%]).\u003c/p\u003e\u003cp\u003eOverall Survival\u003c/p\u003e\n\u003cp\u003ePreoperative pathological diagnosis at the first and final biopsies did not correlate with OS (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.622 and \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.744, respectively) (\u003cstrong\u003eFigure 1-A and 1-B\u003c/strong\u003e), whereas postoperative pathological diagnosis did (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.009) (\u003cstrong\u003eFigure 1-C\u003c/strong\u003e).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eAlthough several studies have reported discordance between preoperative and postoperative pathological diagnoses in chondrosarcoma [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], few have examined second biopsy. Therefore, this provides additional insight into this area. Preoperative first pathological diagnosis was associated with the occurrence of second biopsy in this study. A second biopsy was frequently performed in patients whose preoperative first pathological diagnosis was malignant tumors other than chondrosarcoma (1 of 3 patients [33.3%]), enchondroma (2 of 4 patients [50%]), enchondroma or Grade 1 (2 of 4 patients [50%]), and difficult to diagnose (5 of 6 patients [83.3%]). A second biopsy may be performed in patients whose treatment plan cannot be determined based on the first biopsy results or when there is discordance between clinical findings/imaging findings and first pathological diagnosis.\u003c/p\u003e \u003cp\u003eThe first biopsy method was not associated with the occurrence of second biopsy in this study. First biopsy was performed by needle biopsy in 34 patients (56.7%) and open biopsy in 24 (40.0%), and the biopsy method was unknown in 2 (3.3%). Second biopsies were performed in 9 patients (81.8%) whose first biopsy was needle biopsy and in 2 patients (18.2%) whose first biopsy was open biopsy; this may be due to the smaller sample volume obtained with needle biopsy. Of the 11 patients who underwent a second biopsy, 3 (27.3%) underwent needle biopsy and 8 (72.7%) underwent open biopsy, suggesting that the biopsy method was changed for the second biopsy. If technically possible, open biopsy may be considered at the first biopsy to reduce the likelihood of requiring a second biopsy; however, the biopsy method should be carefully determined based on tumor location. In this study, the median tumor size was 7.9 (2.0\u0026ndash;32.6) cm, and the optimal site for tissue sampling in chondrosarcoma remains a matter of debate. Although there are few reports on the use of new imaging methods in cartilaginous tumor biopsy, the following studies describe new diagnostic imaging methods to distinguish between benign and malignant cartilaginous tumors. Jesus‑Garcia et al. reported that the standardized uptake value (SUV)\u003csub\u003emax\u003c/sub\u003e between 2.0 and 2.2 may represent a threshold range distinguishing chondroma from chondrosarcoma and may be valuable, among others diagnostic methods, in guiding treatment decisions for patients with cartilaginous lesions of the long bones using PET/CT [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. On the other hand, Douis et al. showed that diffusion-weighted magnetic resonance imaging (MRI) cannot differentiate between enchondromas and chondrosarcoma and does not aid in distinguishing low-grade chondroid tumors from high-grade chondrosarcoma [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Detection of \u003cem\u003eIDH1/2\u003c/em\u003e or \u003cem\u003eGNAS\u003c/em\u003e circulating tumor DNA has been reported to be more accurate than pathology for identifying high-grade chondrosarcomas and is associated with poor prognosis [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This approach is expected to complement current standard diagnostic protocols.\u003c/p\u003e \u003cp\u003eThe diagnostic accuracy of biopsy in patients with bone tumors has been reported to be \u0026gt;\u0026thinsp;90% [\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In this study, discordance between preoperative and postoperative diagnoses was observed in 25 of 60 patients (41.7%) at final biopsy, which is consistent with previous reports of 9.5\u0026ndash;59.9% [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] and highlights the diagnostic challenges of chondrosarcoma by biopsy. Discordance between preoperative and postoperative diagnoses was observed in 32 of 60 patients (53.3%) at first biopsy, which decreased to 25 of 60 (41.7%) at final biopsy, suggesting that second biopsy may have value in preoperative pathological diagnosis. A previous report showed that discordance between preoperative and postoperative pathological diagnoses was much higher in pelvic chondrosarcoma than in long-bone chondrosarcoma (64.1% [25 of 39] in the pelvis versus 17.5% [7 of 40] in long-bone)[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In this study, the discordance between preoperative and postoperative pathological diagnoses was 37.5% [6 of 16] in the pelvis and 43.5% [10 of 23] in the extremities, and no such trend was observed.\u003c/p\u003e \u003cp\u003ePreoperative final and postoperative pathological diagnoses were associated with discordance between preoperative and postoperative pathological diagnoses in this study. Of the 24 patients whose preoperative final pathology was Grade 1, 13 patients (54.2%) had the same diagnosis postoperatively, 9 patients (37.5%) were diagnosed with postoperative Grade 2, 1 patient (4.2%) was diagnosed with postoperative Grade 3, and the remaining patient (4.2%) was diagnosed with postoperative dedifferentiated chondrosarcoma. Of the 24 patients whose preoperative final pathology was Grade 2, 19 patients (79.2%) had the same diagnosis postoperatively, 2 patients (8.3%) were diagnosed with postoperative Grade 3, and 3 patients (12.5%) were diagnosed with postoperative dedifferentiated chondrosarcoma. Of the 2 patients whose preoperative final pathology was Grade 3, 1 patient (50.0%) had the same diagnosis postoperatively, and the remaining patient (50.0%) was diagnosed with postoperative Grade 2. These results indicate that Grade 2 may be more reliable than Grade 1 for the final preoperative pathological diagnosis; however, definitive conclusions regarding Grade 3 are limited because few patients were diagnosed preoperatively. This study targeted patients with postoperative pathological diagnoses of conventional or dedifferentiated chondrosarcoma, and it is therefore expected that discordance would be observed in the final preoperative diagnoses of enchondroma or malignant tumors other than chondrosarcoma.\u003c/p\u003e \u003cp\u003ePreoperative diagnosis of dedifferentiated chondrosarcoma is especially challenging. A previous report showed that discordance between preoperative and postoperative diagnoses was observed in 63.6% [7 of 11][\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Discordance between preoperative and postoperative diagnoses was observed in 100% [8 of 8] in this study. Among the 8 patients, the preoperative final pathological diagnosis was Grade 1 in 1 patient, Grade 2 in 3, and malignant tumors other than chondrosarcoma in 4. The pathological diagnosis of dedifferentiated chondrosarcoma depends largely on whether prededifferentiated or dedifferentiated tissue is collected. Patients whose final preoperative pathological diagnosis was Grade 1 or Grade 2 likely had prededifferentiated tissue collected, whereas patients with malignant tumors other than chondrosarcoma likely had dedifferentiated tissue collected. Four patients diagnosed with malignant tumors other than chondrosarcoma included osteosarcoma in 2 patients, osteosarcoma or undifferentiated pleomorphic sarcoma (UPS) in 1, and malignant neoplasm in 1. Sopta et al. showed that in 25 patients with dedifferentiated chondrosarcoma, classification of the high-grade components based on immunohistochemical analyses identified UPS in 18 patients, osteosarcoma in 4, fibrosarcoma in 2, and rhabdomyosarcoma in 1 [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. They emphasized that the complex morphological and phenotypical presentation of dedifferentiated chondrosarcoma requires precise biopsy technique, acquisition of a greater number of specimens for pathohistological verification, and application of advanced pathological techniques in tissue analysis. Imaging is also important for accurately identifying dedifferentiated and prededifferentiated areas. A previous report showed that dedifferentiation within chondrosarcoma may be identified on T2-weighted MRI as areas of reduced signal intensity, and these areas should be preferred biopsy sites [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Another study reported that the optimal SUV\u003csub\u003emax\u003c/sub\u003e cutoff was 7.7 for differentiating intermediate/high-grade from dedifferentiated chondrosarcoma (sensitivity 0.92, specificity 0.9) [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. These findings suggest that MRI and PET/CT may be useful for identifying dedifferentiated and prededifferentiated areas before biopsy. However, some patients have minimal or small dedifferentiated components [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], and spatial caution is required in such cases.\u003c/p\u003e \u003cp\u003eHistological grade is a well-known prognostic factor in chondrosarcoma [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In this study, preoperative pathological diagnosis at the first and final biopsies did not correlate with OS, suggesting that the preoperative pathological diagnosis of biopsy specimens does not accurately reflect prognosis. In contrast, postoperative pathological diagnosis correlated with prognosis. These findings indicate that the grade determined by preoperative pathological evaluation does not accurately reflect tumor prognosis, and caution is required when using it to guide treatment strategies.\u003c/p\u003e \u003cp\u003eAtypical cartilaginous tumors are defined as low-grade intracompartmental appendicular tumors that allow intralesional resection with or without local adjuvant therapy [\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In this study, in addition to 4 patients with long bone tumors, curettage was also performed in 2 patients with pelvic tumors in whom significant functional impairment due to wide dissection was expected. Surgery was associated with discordance between preoperative and postoperative pathological grades, and no discordance was observed in any of the 6 patients who underwent curettage. In cases involving long bones, lesion curettage may have been performed in more carefully selected cases. Distinguishing between low-grade and high-grade chondrosarcoma remains challenging, and preoperative evaluation should be performed using a multidisciplinary approach, including pathology and radiology. Previous systematic reviews have shown that loss of entrapped fatty marrow, bone marrow edema, cortical breakthrough, or extraosseous soft tissue expansion is more frequently observed in high-grade chondrosarcoma than in atypical cartilaginous tumors [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study has some limitations. First, this was a single-center study, and the results may be difficult to extrapolate to other centers; however, the discordance rate between preoperative and postoperative diagnoses was similar to that reported previously [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Second, the small number of patients may have limited the analysis. Future large-scale, multicenter studies may provide additional insights. Finally, this study included patients over a long period (approximately 20 years), and advances in imaging, such as PET/CT, may have influenced the biopsy methods. In this study, PET/CT was performed before biopsy in only 3 patients, and its usefulness remains controversial.\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eOverall, this study highlights the discordance between preoperative and postoperative diagnoses. Discordance was observed in 41.7% of cases based on preoperative final pathological diagnosis and was more common in patients with high-grade chondrosarcoma on postoperative pathology. Predicting postoperative pathological changes before surgery remains difficult, and careful consideration of the surgical procedure is required for each patient by integrating imaging findings with preoperative pathological results.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePET/CT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositron Emission Tomography-Computed Tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOverall Survival\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSUV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandardized Uptake Value\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMagnetic Resonance Imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUPS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUndifferentiated Pleomorphic Sarcoma\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCLINICAL TRIAL NUMBER\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical trial number: not applicable.\u003c/p\u003e\n\n\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the principles of the Declaration of Helsinki. This study was approved by the Ethics Committee of the Nagoya University Graduate School and School of Medicine (Nagoya, Japan) in November 2025 (registration number: 2025-0365).\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article.\u003c/p\u003e\n\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\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOne author (HU) received research funding from the Ministry of Education, Culture, Sports, Science, and Technology of Japan [Grant-in-Aid 23K08696 for Scientific Research (C)].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHU designed and drafted the manuscript, and developed the concept. HU, KK, and SI revised the manuscript and supervised the study. HU, KI, TS, HK, TF, and YN provided the treatment for chondrosarcoma. All the authors have read and approved the final version of this manuscript.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eDepartment of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003eDepartment of Orthopedic Surgery, Nagoya University Hospital, Nagoya, Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e3\u003c/sup\u003eDepartment of Rehabilitation Medicine, Nagoya University Hospital, Nagoya, Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e4\u003c/sup\u003eDepartment of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSharif B, Lindsay D, Saifuddin A. The role of imaging in differentiating low-grade and high-grade central chondral tumours. Eur J Radiol. 2021;137:109579.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDouis H, Saifuddin A. The imaging of cartilaginous bone tumours. II. Chondrosarcoma. Skeletal Radiol. 2013;42(5):611\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVijayakumar G, Kasson L, Jones CM, Lee L, Colman MW, Gitelis S, Blank AT. Evaluation of Local Recurrence and Diagnostic Discordance in Chondrosarcoma Patients Undergoing Preoperative Biopsy. Anticancer Res. 2023;43(7):3069\u0026ndash;77.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHarvard H, Badejo MA, Levine N, Cantor N, Visgauss J, Brigman B, Eward WC. Core needle biopsy of periacetabular chondrosarcoma often results in undergrading but does not change management by experienced orthopaedic oncologists. Sci Rep. 2025;15(1):33738.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoitman PD, Farfalli GL, Ayerza MA, Muscolo DL, Milano FE, Aponte-Tinao LA. Is Needle Biopsy Clinically Useful in Preoperative Grading of Central Chondrosarcoma of the Pelvis and Long Bones? Clin Orthop Relat Res. 2017;475(3):808\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCastelo F, Faria A, Miranda H, Oliveira V, Cardoso P. Curettage or Resection? A Review on the Surgical Treatment of Low-Grade Chondrosarcomas. Cureus. 2023;15(5):e39637.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDierselhuis EF, Goulding KA, Stevens M, Jutte PC. Intralesional treatment versus wide resection for central low-grade chondrosarcoma of the long bones. Cochrane Database Syst Rev. 2019;3(3):CD010778.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim W, Lee JS, Chung HW. 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Paediatric bone lesions: diagnostic accuracy of imaging correlation and CT-guided needle biopsy for differentiating benign from malignant lesions. Br J Radiol. 2021;94(1120):20201234.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCengiz T, Yurtbay A, Muslu O, Aydin Simsek S, Ozbalci AB, Coskun HS, Baris YS, Dabak N. Evaluation of the Diagnostic Accuracy of Percutaneous Core Needle Biopsy in Bone and Soft Tissue Tumors. Acta Chir Orthop Traumatol Cech. 2024;91(6):376\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSopta J, Dordevic A, Tulic G, Mijucic V. Dedifferentiated chondrosarcoma: our clinico-pathological experience and dilemmas in 25 cases. J Cancer Res Clin Oncol. 2008;134(2):147\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaifuddin A, Mann BS, Mahroof S, Pringle JA, Briggs TW, Cannon SR. Dedifferentiated chondrosarcoma: use of MRI to guide needle biopsy. Clin Radiol. 2004;59(3):268\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnnovazzi A, Anelli V, Zoccali C, Rumi N, Persichetti A, Novello M, Sciuto R, Bertoni F, Ferraresi V, Biagini R. (18)F-FDG PET/CT in the evaluation of cartilaginous bone neoplasms: the added value of tumor grading. Ann Nucl Med. 2019;33(11):813\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDehner CA, Maloney N, Amini B, Jennings JW, McDonald DJ, Wang WL, Chrisinger JSA. Dedifferentiated chondrosarcoma with minimal or small dedifferentiated component. Mod Pathol. 2022;35(7):922\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang M, Song Y, Liu S, Sun W. Effect of surgery and radiotherapy on overall survival in patients with chondrosarcoma: A SEER-based study. J Orthop Surg (Hong Kong). 2022;30(1):10225536221086319.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang W, Zhen J. Prognostic Factors and Surgical Impact of Non-metastatic Conventional Chondrosarcoma of the Extremities. Orthop Surg. 2023;15(12):3288\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeckers C, Steyvers MJ, Hannink G, Schreuder HWB, de Rooy JWJ, Van Der Geest ICM. Can MRI differentiate between atypical cartilaginous tumors and high-grade chondrosarcoma? A systematic review. Acta Orthop. 2020;91(4):471\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlhumaid SM, Alharbi At, Aljubair H. Magnetic Resonance Imaging Role in the Differentiation Between Atypical Cartilaginous Tumors and High-Grade Chondrosarcoma: An Updated Systematic Review. Cureus. 2020;12(10):e11237.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Table 1,3,4,5","content":"\u003cp\u003eTable 1,3,4,5 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-cancer","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcan","sideBox":"Learn more about [BMC Cancer](http://bmccancer.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcan/default.aspx","title":"BMC Cancer","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"chondrosarcoma, biopsy, pathology, grade","lastPublishedDoi":"10.21203/rs.3.rs-9324197/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9324197/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground.\u003c/h2\u003e \u003cp\u003eAlthough accurate preoperative assessment of chondrosarcoma tumor grade remains difficult, evaluating discordance between preoperative and postoperative diagnoses is important for selecting an appropriate surgical procedure.\u003c/p\u003e\u003ch2\u003eMethods.\u003c/h2\u003e \u003cp\u003eWe retrospectively reviewed 60 patients with chondrosarcoma who visited Nagoya University Hospital and had both preoperative and postoperative pathological diagnoses. Factors associated with the occurrence of second biopsy and discordance between preoperative and postoperative pathological diagnoses were assessed.\u003c/p\u003e\u003ch2\u003eResults. A\u003c/h2\u003e \u003cp\u003esecond biopsy was performed in 11 of 60 patients (18.3%). Preoperative first pathological diagnosis was associated with the occurrence of second biopsy (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Discordance between preoperative and postoperative diagnoses was observed in 25 of 60 patients (41.7%), and the preoperative final pathological grade was underestimated in all but one patient with postoperative grades 1, 2, and 3 chondrosarcomas. Surgery, preoperative final pathological diagnosis, and postoperative pathological diagnosis were found to influence the discordance between the preoperative and postoperative pathological grades (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.029, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.025, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005, respectively).\u003c/p\u003e\u003ch2\u003eConclusions.\u003c/h2\u003e \u003cp\u003eIn approximately 40% of patients, preoperative grade of chondrosarcoma was underestimated. Predicting postoperative pathological changes before surgery remains difficult; therefore, careful consideration of the surgical procedure is required for each patient by integrating imaging findings with preoperative pathological results.\u003c/p\u003e","manuscriptTitle":"The discordance between preoperative and postoperative pathological diagnoses in chondrosarcoma: from a specialized sarcoma treatment center in Japan ","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-11 06:18:15","doi":"10.21203/rs.3.rs-9324197/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"269799514910857045007049078598089642161","date":"2026-05-13T23:28:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-10T09:23:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"163303607445985289961135497693707805328","date":"2026-05-06T07:26:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-05T02:00:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"81160048598365584240118269309824138420","date":"2026-05-05T01:43:18+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-29T05:56:31+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-08T09:26:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-08T07:04:23+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-08T07:04:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Cancer","date":"2026-04-05T05:12:39+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-cancer","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcan","sideBox":"Learn more about [BMC Cancer](http://bmccancer.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcan/default.aspx","title":"BMC Cancer","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6e00732c-72bf-42a1-b5bb-9edc740f2248","owner":[],"postedDate":"May 11th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"269799514910857045007049078598089642161","date":"2026-05-13T23:28:26+00:00","index":64,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-10T09:23:09+00:00","index":63,"fulltext":""},{"type":"reviewerAgreed","content":"163303607445985289961135497693707805328","date":"2026-05-06T07:26:42+00:00","index":60,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-05T02:00:57+00:00","index":44,"fulltext":""},{"type":"reviewerAgreed","content":"81160048598365584240118269309824138420","date":"2026-05-05T01:43:18+00:00","index":43,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T06:18:15+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-11 06:18:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9324197","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9324197","identity":"rs-9324197","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}