Thoracolithiasis: A Rare and Frequently Underrecognized Entity – A Retrospective Single- Center Study and Comprehensive Literature Review

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Systematic data on non-mobile thoracolithiasis and its clinical context are scarce. This study aimed to characterize the clinical, radiologic, etiologic, and geographic features of non-mobile thoracolithiasis, to explore isolated versus secondary (malignancy-associated) forms, and to identify scenarios in which these lesions mimic malignant pleural nodules. Materials and Methods This retrospective, observational study included adult patients diagnosed with thoracolithiasis at a tertiary thoracic surgery center between January 2010 and December 2024. Eligible cases had radiologic and/or surgical confirmation and complete clinical and imaging data. Demographic, clinical, radiologic, and surgical variables, including asbestos exposure and coexisting thoracic disease, were collected. Patients were stratified by sex, symptom status, calcification, and isolated versus secondary thoracolithiasis. Statistical comparisons used the Mann–Whitney U test and Chi-square or Fisher’s exact test (two-tailed p < 0.05). A comparative literature review of PubMed and Scopus was performed. Results Twenty patients with pathologically confirmed thoracolithiasis (mean age 64.0 ± 10.5 years; 70% male; 75% ever-smokers) were included. All lesions were non-mobile; 60% were non-calcified, with a mean maximum diameter of 29.4 ± 17.8 mm. Thoracolithiasis coexisted with lung cancer in 40% and with other thoracic disease in 30%; 30% were isolated. Patients with calcified lesions were older than those with non-calcified lesions (70.0 vs 60.0 years, p = 0.0227). Lung cancer occurred exclusively in older male smokers and was associated with male sex (p = 0.010) and smoking history (p = 0.027). Isolated thoracolithiasis was more frequent in female non-smokers, and all isolated cases underwent diagnostic exploration (100% vs 35.7%, p = 0.0253). Asbestos-exposed patients (25%) originated exclusively from inland provinces, whereas most non-exposed patients resided in a coastal, non–asbestos-endemic region. Conclusion Non-mobile thoracolithiasis exhibits two distinct clinical–etiologic profiles: a secondary type in older male smokers with thoracic malignancy, and an isolated type in non-smoking women without additional thoracic disease. Non-mobile, often non-calcified thoracoliths in low-risk patients frequently mimic malignant pleural nodules and may lead to avoidable thoracoscopic or open exploration. Recognizing this broader spectrum of thoracolithiasis may help refine diagnostic algorithms and reduce unnecessary invasive procedures. Thoracolithiasis pleural loose body non-mobile thoracolith pleural nodule VATS Figures Figure 1 Figure 2 INTRODUCTION Thoracolithiasis is an uncommon benign pleural condition characterized by one or more small intrapleural loose bodies (“thoracoliths”), typically calcified and freely mobile within the pleural cavity. Most reported cases are discovered incidentally during thoracic imaging or at surgery, as patients are usually asymptomatic [ 1 , 2 ]. In the largest CT-based series to date, Kinoshita et al. reported an incidence of approximately 0.086% among thoracic CT examinations, underscoring the rarity of this entity despite the widespread use of modern imaging [ 3 ]. Although thoracolithiasis is clinically benign, failure to recognize it may lead to misinterpretation as malignant or other pleural pathology and precipitate unnecessary invasive diagnostic procedures [ 4 , 5 ]. In this context, systematic data on non-mobile thoracolithiasis and its clinical correlations are extremely limited. Most available literature consists of single case reports or very small series, and there is a paucity of data on associations with underlying thoracic malignancy, patient demographics, or symptomatology [ 3 , 5 , 6 ] The present study contributes to the limited body of knowledge by presenting a single-center series of 20 patients with non-mobile thoracolithiasis, providing descriptive clinical, radiologic, etiologic, and geographic characteristics. By comparing isolated versus secondary (malignancy-associated) forms and exploring factors such as sex, smoking status, density, symptomatology, and timing of diagnosis, we aim to (1) to refine the conceptual framework of thoracolithiasis as a heterogeneous pleural entity, including an examination of its potential correlations with geographic characteristics, and (2) highlight scenarios in which non-mobile thoracolithiasis can closely mimic malignant pleural nodules, leading to potentially avoidable surgical exploration. MATERIAL & METHOD Study Design and Setting This was a retrospective, observational, descriptive study conducted in the Department of Thoracic Surgery at Ondokuz Mayıs University Faculty of Medicine. Patients diagnosed with thoracolithiasis between January 2010 and December 2024 were reviewed retrospectively. Study Population The study population consisted of adult patients who presented to our hospital within the specified period and were found to have imaging findings compatible with thoracolithiasis on thoracic imaging, particularly thoracic computed tomography (CT). Cases diagnosed intraoperatively or confirmed pathologically were also included. Each patient was evaluated only once. Inclusion Criteria Patients were eligible for inclusion if they met the following criteria: Age ≥ 18 years, Diagnosis of thoracolithiasis between January 2010 and December 2024, Diagnosis confirmed radiologically (CT, chest X-ray) or surgically, Complete availability of clinical records and imaging data, Availability of at least one sequential imaging study to assess nodule mobility was considered preferable, though not mandatory. Both asymptomatic, incidentally detected cases and patients evaluated due to symptoms during the diagnostic process were included. Exclusion Criteria Patients were excluded if any of the following applied: Age < 18 years, Inability to confirm the diagnosis radiologically or surgically, Missing or inaccessible imaging (CT, X-ray) or clinical records, Cases in which thoracolithiasis remained only a suspected diagnosis and subsequent follow-up revealed an alternative pathology, Nodular calcifications clearly attributable to prior invasive pleural procedures (e.g. post–talc pleurodesis), Calcified foci arising in the context of secondary malignant pleural disease (e.g. pleural metastases, mesothelioma), Patients who were diagnosed at our center but followed exclusively at another institution, with insufficient clinical information available. Data Collection Eligible cases were identified through retrospective searches of the hospital information system, picture archiving and communication system (PACS), operative reports, and the pathology database. Keywords used in the search included “thoracolithiasis”, “pleural loose body”, and “mobile pleural nodule”. For each patient, the following variables were collected: Demographic data: age, sex, city of residence, year of presentation, primary reason for presentation Clinical data: presence and type of symptoms, comorbidities, duration of follow-up Radiologic data: type of imaging modality, lesion localization, number of lesions, maximum diameter (mm), density (calcified vs non-calcified), mobility status, and other concomitant pleural or pulmonary findings Intervention data: clinical follow-up vs surgical intervention (VATS / thoracotomy), type of surgical procedure, pathology result Diagnostic process: duration of pre-diagnostic follow-up, mode of diagnosis (radiologic vs surgical) All data were anonymized and recorded in a Microsoft Excel spreadsheet. Imaging findings relevant to the diagnosis were reviewed independently by more than one investigator, and parameters such as mobility, density, and positional change were assessed by consensus. Literature Review A comparative literature review was also planned. For this purpose, a systematic search of PubMed and Scopus was performed using the keywords “thoracolithiasis”, “pleural loose body”, and “calcified mobile pleural nodule”. Published case reports and case series were identified, and their clinical, radiologic, and pathological findings were summarized and compared with the results of the present study. Ethical Approval This retrospective study was conducted in accordance with the ethical standards of the institutional and national research committees and with the 1964 Declaration of Helsinki and its later amendments. The study protocol was reviewed and approved by the Ondokuz Mayıs University Clinical Research Ethics Committee (Approval No: 2025/239 , June 2025 ). The requirement for informed consent was waived due to the retrospective nature of the study. STATISTICAL ANALYSIS All statistical analyses were performed using IBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY, USA) . Continuous variables were expressed as mean ± standard deviation (SD) or median (interquartile range, IQR) , as appropriate. Categorical variables were presented as numbers and percentages [n (%)] . Comparisons between two independent groups (e.g., male vs. female, symptomatic vs. asymptomatic, calcified vs. non-calcified) were performed using the Mann–Whitney U test for continuous variables and the Chi-square or Fisher’s exact test for categorical variables. A two-tailed p-value < 0.05 was considered statistically significant. RESULTS A total of 20 patients with pathologically confirmed thoracolithiasis were included in the study. The baseline demographic, clinical, radiologic, and surgical characteristics are summarized in Table 1 . Representative imaging example of non-mobile thoracolithiasis is shown in Figure 1. Most patients were residents of Samsun province (12/20, 60%), while the remaining cases were referred from neighboring provinces (Amasya, Corum, Ordu, Tokat) and one patient from Baku, Azerbaijan. Male and female patients demonstrated similar age, lesion size, and number of thoracoliths; however, significant sex-related differences were observed in smoking history and associated thoracic pathology, as detailed in Table 2 . Symptomatic and asymptomatic patients showed similar demographic and radiologic characteristics. Minor differences were observed in lesion laterality and detection mode, with symptomatic cases more often right sided and less frequently incidental (p = .0306 and p = .0036, respectively), although these findings had limited clinical significance. Patients with calcified thoracoliths were significantly older than those with non-calcified lesions (70.0 ± 7.4 vs 60.0 ± 10.7 years, p = .0227). No significant differences were observed in lesion size, symptom status, smoking history, or associated thoracic pathology between the two groups. Patients with coexisting lung cancer were predominantly older male smokers, showing a trend toward higher age compared to those without cancer (69.4 ± 8.2 vs 60.4 ± 10.9 years, p = .0585). The presence of lung cancer was significantly associated with male sex (p = .010) and smoking history (p = .027), while other clinical and radiologic features were comparable between groups. Patients were classified as having isolated thoracolithiasis when no concomitant thoracic disease was present, and as secondary when thoracolithiasis coexisted with lung cancer or other thoracic pathology. Compared with secondary cases, isolated thoracolithiasis was more common in female non-smokers and was predominantly managed by diagnostic exploration ( Table 3 ). To explore potential environmental contributors, patients were stratified according to a history of asbestos exposure (5/20, 25%). Asbestos-exposed patients were slightly older on average, and a striking geographic clustering was observed: all exposed patients originated from inland provinces (Amasya, Corum, Tokat), whereas almost all non-exposed patients resided in Samsun (p = .0004). Coronary artery disease (80.0% vs 6.7%, p = .0049) and hypothyroidism (60.0% vs 0.0%, p = .0088) were also more frequent in the asbestos-exposed group, although the small sample size limits interpretation. In contrast, asbestos exposure was not clearly associated with lung cancer (20.0% vs 46.7%, p > .05) or with differences in symptomatology, lesion size, density, or timing of diagnosis. Thoracolithiasis was identified preoperatively in 35% of patients and intraoperatively in 65%. Patients with preoperative diagnosis were significantly older (69.9 vs 60.8 years, p = .0294), whereas intraoperative detection was more often associated with larger lesions and diagnostic explorations. Representative intraoperative and postoperative findings of an isolated, non-malignant thoracolithiasis case are shown in Figure 2a–c, demonstrating the characteristic gross morphology of the thoracolith, the single-port VATS incision used for removal, and the postoperative chest radiograph confirming full re-expansion of the lung without residual pathology. DISCUSSION This single-center 20-patient series adds several important observations to the limited thoracolithiasis literature. First, all lesions in our cohort were non-mobile, in contrast to the traditional description of thoracolithiasis as a freely mobile pleural loose body [1, 3]. Second, we demonstrate that thoracolithiasis is not a uniform entity but appears to segregate into two distinct etiologic phenotypes: a secondary, male, smoker, cancer-associated type and an isolated, female, non-smoker type. Notably, these patterns also demonstrated a geographic dimension, with isolated cases predominantly occurring in patients residing in non–asbestos-endemic areas, whereas asbestos-exposed patients originated exclusively from inland provinces known for environmental exposure. Third, we show that isolated non-mobile thoracoliths are particularly prone to misdiagnosis as malignant pleural nodules, resulting in a high rate of unnecessary exploratory surgery. Previous CT-based series and narrative reviews have emphasized three main features of classic thoracolithiasis: rarity, left-sided predominance, and mobility [1, 3, 6]. Kinoshita et al. described 11 cases of calcified intrapleural loose bodies, most located in the left lower hemithorax and all demonstrating mobility on serial imaging [3] Strzelczyk et al. referred to these lesions as “rolling stones in the pleural space” and proposed that positional change on CT is a key diagnostic criterion [1]. Similarly, Suwatanapongched et al. reported thin-section CT findings in nine patients and confirmed the typical left lower hemithorax distribution, ovoid morphology, and frequent calcification [6]. Gayer also highlighted mobility and laminated internal architecture as important clues to the diagnosis [5]. In contrast, our series shows a more balanced laterality (right 50%, left 45%) and, importantly, no radiologic or intraoperative mobility in any case. This pattern aligns more closely with recent case reports describing immobile thoracolithiasis anchored to pleural fat or presenting as pedunculated-appearing pleural masses, which challenge the classical notion that mobility is obligatory for diagnosis [7-9]. Our data suggest that non-mobile thoracolithiasis may be under-recognized and under-reported, particularly when coexisting with other thoracic pathology. A growing number of reports document atypical thoracoliths that mimic pleural plaques, metastases, or even primary malignancies [7, 10, 11]. Cha et al. described thoracolithiasis simulating an asbestos-related pleural plaque in an asbestos-exposed patient [7]. Bolca et al. reported a pearl-like thoracolith that closely resembled a pleural or mediastinal tumor [10]. Wong et al. recently published a case of thoracolith mimicking pulmonary osteosarcoma metastasis, emphasizing the risk of over-treating this benign entity [11]. Our isolated, non-mobile, mostly non-calcified lesions fit well within this emerging spectrum of “malignancy mimics”. Notably, in our cohort, these atypical presentations clustered among patients residing in non–asbestos-endemic coastal regions, whereas asbestos-exposed individuals originated exclusively from inland provinces. This geographic separation suggests that environmental background may influence both the radiologic appearance and diagnostic ambiguity of thoracolithiasis, further complicating distinction from malignant pleural disease. In our cohort, all six isolated thoracolithiasis cases occurred in non-smoking or low-risk women without coexisting thoracic disease, yet 100% of these patients underwent diagnostic exploratory surgery because malignancy could not be confidently excluded preoperatively. This finding parallels prior reports in which immobile or atypical thoracoliths were only diagnosed definitively at thoracoscopy or thoracotomy [10, 12, 13]. These observations underscore the need to broaden the radiologic and clinical definition of thoracolithiasis beyond the classical mobile, calcified nodule. Consistent with previous series, most of our patients were asymptomatic, and symptom presence did not correlate with lesion size or calcification [1, 2, 14]. Kang et al. and others have reported that symptoms, when present, tend to occur in patients with multiple or larger thoracoliths and often improve after surgical removal [14, 15]. In our series, however, symptomatic cases were defined by a combination of clinical judgement and exclusion of alternative causes, which may partly explain the absence of a clear size–symptom relationship. More intriguingly, we found that symptoms were associated with right-sided location and a borderline association with prior tuberculosis. This pattern supports the hypothesis that chronic pleural inflammation—whether due to prior infection or other inflammatory processes—may contribute both to thoracolith formation and to pleuritic pain or cough by altering local pleural mechanics. Similar associations between thoracolithiasis, prior infection, and pleural adhesions have been noted in individual case reports [15, 16]. While causality cannot be established in our small sample, these findings align with one of the major proposed pathogenetic pathways: post-inflammatory organization and detachment of necrotic pleural or pericardial fat [2, 12, 17]. The observed association between calcification and older age in our cohort (70 vs 60 years) supports a time-dependent, degenerative model of thoracolith evolution. Early-stage lesions may be non-calcified, composed primarily of necrotic fat and fibrous tissue, and only gradually develop calcifications over years. This concept is in line with histopathologic descriptions in prior series, where centrally necrotic fat cores showed increasing fibrosis and calcification over time [13, 18]. Our finding that symptom status and lesion size do not differ between calcified and non-calcified groups further suggests that calcification is a marker of chronicity rather than clinical aggressiveness. From a radiologic perspective, however, calcification may be a useful clue favoring thoracolithiasis over malignant disease, especially when combined with peripheral pleural location and stability over time [3, 5]. Non-calcified lesions, in contrast, may be more easily mistaken for malignant nodules, particularly when non-mobile and isolated. Indeed, in our cohort, the majority of unnecessary surgical explorations were performed for these non-calcified thoracoliths, as their radiologic appearance frequently mimicked malignancy and raised concern for occult metastatic or primary disease. The high proportion of patients with coexisting lung cancer in our cohort (40%), all male smokers, indicates that thoracolithiasis may frequently arise in the context of chronic smoking-related and malignant pleural inflammation. Prior CT series and case reports have noted coexisting pulmonary or pleural disease in a substantial subset of thoracolithiasis patients, including emphysema, prior surgery, or malignancy [3, 5, 6]. Our data extend these observations by demonstrating a clear sex- and smoking-linked phenotype: Secondary thoracolithiasis in older male smokers with thoracic malignancy or other significant pathology, versus Isolated thoracolithiasis in younger or middle-aged non-smoking women without malignancy. In practical terms, this dichotomy has important implications: In high-risk patients (older male smokers with lung cancer), thoracoliths are usually discovered incidentally during oncologic work-up or surgery and rarely influence management. In low-risk patients (non-smoking women without cancer), non-mobile thoracoliths are more likely to be interpreted as primary malignant pleural nodules, triggering decision-making cascades that end in diagnostic thoracoscopy or thoracotomy. Taken together, our findings—supported by recent literature—suggest that the diagnostic concept of thoracolithiasis should be expanded along two axes: Mobility spectrum: Thoracoliths may range from freely mobile to partially adherent to fully immobile, particularly when anchored to pleural fat or in the setting of pleural adhesions [7-9]. Etiologic spectrum: Thoracolithiasis may represent either an isolated degenerative process in otherwise healthy pleura or a secondary sequel of chronic inflammatory or malignant pleural disease [3, 12, 17]. For radiologists and clinicians, several practical points emerge: Non-mobile, pleural-based nodules in low-risk patients—especially non-smoking women without other suspicious findings—should prompt consideration of non-mobile thoracolithiasis in the differential diagnosis, even in the absence of demonstrated mobility. Review of prior imaging for subtle change in position, careful assessment of the pleural–parenchymal interface, and attention to fatty or laminated internal structure may provide additional clues [5, 11]. When thoracolithiasis is strongly suspected and malignancy risk is otherwise low, short-interval imaging follow-up rather than immediate diagnostic thoracoscopy may be reasonable, although this approach requires validation in larger cohorts. This study has several limitations. It is a single-center, retrospective series with a small sample size (N = 20), which limits statistical power and generalizability. Confidence intervals are wide, and several clinically relevant associations (e.g. tuberculosis history and symptoms, lung cancer and age, lesion size and diagnostic timing) approached but did not reach conventional statistical significance. As our series includes only non-mobile lesions, direct comparison with mobile thoracolithiasis was not possible. Finally, referral and selection bias are likely, as all patients ultimately underwent surgery, potentially over-representing diagnostically challenging or symptomatic cases. CONCLUSION In this 20-patient series, thoracolithiasis presented exclusively as non-mobile pleural nodules, challenging the traditional view that mobility is a mandatory diagnostic feature. Our data support the existence of two distinct clinical–etiologic profiles: A secondary type , occurring predominantly in older male smokers with lung cancer or other significant thoracic pathology; and An isolated type , seen mainly in non-smoking women without additional thoracic disease, in whom non-mobile thoracoliths frequently mimicked malignant pleural nodules and led to unnecessary diagnostic exploration. Calcification was associated with older age, consistent with a time-dependent degenerative process, whereas symptomatology appeared more closely related to side (right hemithorax) and prior tuberculosis than to lesion size or density. Recognition that thoracolithiasis may be non-mobile, non-calcified, and isolated—particularly in low-risk patients—is crucial to avoid misdiagnosis and potentially prevent avoidable invasive procedures. Future multicenter studies with larger cohorts, including both mobile and non-mobile lesions, are needed to refine diagnostic criteria and to develop evidence-based management strategies for this rare but clinically relevant pleural entity. Declarations Disclosures: All authors have nothing to disclose Funding: The authors received no financial support for this article's research, authorship, and/or publication. Conflicts of interest/Competing interests : The authors have no relevant financial or non-financial interests to disclose. Availability of data and material: The data supporting this study's findings are available from the corresponding author upon request. Ethics approval : The study was conducted with the approval of the Ondokuz University Clinical Research Ethics Committee (Decision no: 2025/239, Approval date: 26/06/2025). Informed Consent Statement: All participants gave written informed consent. Clinical trial number: Not applicable. Author Contributions: Conception and design of the work, supervision, and manuscript drafting: C.İ., M.G.P., B.C.Ö.; Data collection, analysis, and interpretation of the data: M.G.P., B.C.Ö., H.K., B.Ç., Y.B.B.; Statistical analysis: C.İ., H.K.; Critical manuscript revision: all authors. Approval of the final manuscript: all authors. References Strzelczyk J, et al. Rolling stones in the pleural space: thoracoliths on CT, and a review of the literature. Clin Radiol. 2009;64(1):100–4. Peungjesada S, Gupta P, Mottershaw A. Thoracolithiasis: a case report. Clin Imaging. 2012;36(3):228–30. Kinoshita F, et al. Thoracolithiasis: 11 cases with a calcified intrapleural loose body. J Thorac Imaging. 2010;25:64–7. Iwasaki T, et al. Surgically removed thoracolithiasis: report of two cases. Ann Thorac Cardiovasc Surg. 2006;12(4):279–82. Gayer G. Thoracolithiasis—computed tomography findings of intrapleural loose bodies. Semin Ultrasound CT MR. 2017;38(6):634–40. Suwatanapongched T, Nitiwarangkul C. Thin-section CT findings of thoracolithiasis. Jpn J Radiol. 2017;35:350–7. Cha YK, et al. Thoracolithiasis mimicking a pleural plaque in a patient with a history of asbestos exposure: a case report. J Korean Soc Radiol. 2017;77:245–8. Kim S, et al. Clinical, electrodiagnostic and imaging features of true neurogenic thoracic outlet syndrome: experience at a tertiary referral center. J Neurol Sci. 2019;404:115–23. Yamamoto N, Onoda K. Thoracolithiasis: a rare pearl earring-like lesion. Indian J Thorac Cardiovasc Surg. 2024;40(4):497–9. Bolca C, Trahan S, Fréchette É. Intrapleural thoracolithiasis: a rare intrathoracic pearl-like lesion. Thorac Cardiovasc Surg. 2011;59:445–6. Wong M et al. Thoracolith mimicking pulmonary osteosarcoma metastasis. J Radiol Case Rep. 2024. Kataoka K, et al. Thoracoscopically removed thoracolithiasis. Kyobu Geka. 2010;63(12):1066–9. Komatsu T, Sowa T, Fujinaga T. A case of thoracolithiasis diagnosed thoracoscopically. Int J Surg Case Rep. 2012;3(9):415–6. Kang N, et al. A rare case of numerous thoracolithiasis with chest discomfort. Respir Med Case Rep. 2018;25:264–6. Hsu F, Huang TS, Pu TW. Formation of a rare curve-shaped thoracolith documented on serial chest computed tomography images: a case report. World J Clin Cases. 2023;11:2329–35. Tsuchiya T, et al. A case of migrated thoracolithiasis. J Thorac Imaging. 2009;24(4):325–7. Kosaka S, et al. Thoracolithiasis Jpn J Thorac Cardiovasc Surg. 2000;48(5):318–21. Ogushi A, Sugioka T, Nishiyama M, Thoracolithiasis. J Gen Fam Med. 2019;20:122–3. Tables Table 1. Baseline demographic, clinical, radiologic, and surgical characteristics of patients with thoracolithiasis (N = 20) Variable n (%) / Mean ± SD a Age (years) 64.0 ± 10.5 Sex Male 14 (70) Female 6 (30) Laterality Right 10 (50) Left 9 (45) Bilateral 1 (5) Lesion characteristics Mean maximum diameter (mm) 29.4 ± 17.8 Mean number per patient 1.2 ± 0.8 Calcified 8 (40.0) Non-calcified 12 (60.0) Mobile 0 (0.0) Associated thoracic pathology Lung cancer 8 (40.0) Other thoracic disease 6 (30.0) None 6 (30.0) Clinical presentation Symptomatic (chest pain, cough, dyspnea) 5 (25.0) Asymptomatic / incidental 12 (60.0) Not recorded 3 (15.0) Smoking history Active or former smoker 15 (75.0) Non-smoker 5 (25.0) Surgical approach VATS b 14 (70.0) Thoracotomy 6 (30.0) Primary surgical indication Diagnostic exploration 10 (50.0) Lobectomy 7 (35.0) Wedge resection 3 (15.0) Data are presented as mean ± SD or n (%). a SD: Standard Deviation; b VATS: Video-Assisted Thoracoscopic Surgery Table 2. Comparison of demographic, clinical, radiologic, and surgical characteristics according to sex Variable Male (n=14) Female (n=6) p-value Age (years, mean ± SD a ) 66.1 ± 9.7 59.0 ± 11.8 .212 Lesion size (mm, mean ± SD) 30.2 ± 18.1 27.5 ± 16.9 .758 Number of thoracoliths (mean ± SD) 1.3 ± 0.9 1.0 ± 0.7 .480 Smoking history 14 (100 %) 1 (16.7 %) .00038 Lung cancer 8 (57.1 %) 0 (0 %) .018 No associated thoracic disease 2 (14.3 %) 4 (66.7 %) .022 Data are presented as mean ± SD or n (%). a SD: Standard Deviation Table 3. Comparison of demographic, clinical, radiologic, and surgical characteristics between isolated and secondary thoracolithiasis Variable Isolated (n = 6) Secondary (n = 14) p-value Age (years, mean ± SD a ) 61.5 ± 9.8 65.3 ± 10.9 .431 Sex (male) 2 (33.3 %) 12 (85.7 %) .0374 Smoking history (active/former) 2 (33.3 %) 13 (92.9 %) .0139 Lesion size (mm, mean ± SD) 33.3 ± 18.2 27.7 ± 17.4 .471 Calcified lesion 1 (16.7 %) 7 (50.0 %) .197 Symptomatic presentation 2 (33.3 %) 3 (21.4 %) .598 Surgical procedure Diagnostic exploration 6 (100 %) 5 (35.7 %) .0253 Lobectomy 0 (0 %) 7 (50.0 %) - Wedge resection 0 (0 %) 2 (14.3 %) - Timing of diagnosis Preoperative 1 (16.7 %) 6 (42.9 %) .291 Intraoperative 5 (83.3 %) 8 (57.1 %) - Data are presented as mean ± SD or n (%). a SD: Standard Deviation Additional Declarations No competing interests reported. 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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-8314067","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":571393694,"identity":"0d760093-63f8-4900-97c1-db4f3249198e","order_by":0,"name":"Caner 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1","display":"","copyAsset":false,"role":"figure","size":61310,"visible":true,"origin":"","legend":"\u003cp\u003eContrast-enhanced computed tomography showing a well-defined, non-mobile pleural nodule consistent with thoracolithiasis in the left lower hemithorax.\u003c/p\u003e","description":"","filename":"Resim1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8314067/v1/4133fe6edcf9fbafd6f42bdb.jpeg"},{"id":100362128,"identity":"34cc4ecf-b547-473a-aa68-ca058f8ab610","added_by":"auto","created_at":"2026-01-16 07:46:12","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":115824,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative case of isolated, non-malignant thoracolithiasis.\u003cbr\u003e\n \u003cstrong\u003e(a)\u003c/strong\u003e Gross appearance of the excised thoracolith showing a smooth, lobulated surface with focal calcifications.\u003cbr\u003e\n \u003cstrong\u003e(b)\u003c/strong\u003e Postoperative view demonstrating the single-port VATS incision and chest tube placement site.\u003cbr\u003e\n \u003cstrong\u003e(c)\u003c/strong\u003e Postoperative chest X-ray confirming full lung expansion and absence of residual lesion or effusion.\u003c/p\u003e","description":"","filename":"Resim2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8314067/v1/c3df699fdb1c8b3247fc46b0.jpeg"},{"id":100381061,"identity":"3efc1314-2c5c-445d-8c5b-45a27433d626","added_by":"auto","created_at":"2026-01-16 10:37:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1576176,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8314067/v1/2339b90d-1a82-44dd-bc93-c76663366c77.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Thoracolithiasis: A Rare and Frequently Underrecognized Entity – A Retrospective Single- Center Study and Comprehensive Literature Review","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eThoracolithiasis is an uncommon benign pleural condition characterized by one or more small intrapleural loose bodies (\u0026ldquo;thoracoliths\u0026rdquo;), typically calcified and freely mobile within the pleural cavity. Most reported cases are discovered incidentally during thoracic imaging or at surgery, as patients are usually asymptomatic [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In the largest CT-based series to date, Kinoshita et al. reported an incidence of approximately 0.086% among thoracic CT examinations, underscoring the rarity of this entity despite the widespread use of modern imaging [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Although thoracolithiasis is clinically benign, failure to recognize it may lead to misinterpretation as malignant or other pleural pathology and precipitate unnecessary invasive diagnostic procedures [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this context, systematic data on non-mobile thoracolithiasis and its clinical correlations are extremely limited. Most available literature consists of single case reports or very small series, and there is a paucity of data on associations with underlying thoracic malignancy, patient demographics, or symptomatology [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] The present study contributes to the limited body of knowledge by presenting a single-center series of 20 patients with non-mobile thoracolithiasis, providing descriptive clinical, radiologic, etiologic, and geographic characteristics. By comparing isolated versus secondary (malignancy-associated) forms and exploring factors such as sex, smoking status, density, symptomatology, and timing of diagnosis, we aim to (1) to refine the conceptual framework of thoracolithiasis as a heterogeneous pleural entity, including an examination of its potential correlations with geographic characteristics, and (2) highlight scenarios in which non-mobile thoracolithiasis can closely mimic malignant pleural nodules, leading to potentially avoidable surgical exploration.\u003c/p\u003e"},{"header":"MATERIAL \u0026 METHOD","content":"\u003cp\u003e\u003cstrong\u003eStudy Design and Setting\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis was a retrospective, observational, descriptive study conducted in the Department of Thoracic Surgery at Ondokuz Mayıs University Faculty of Medicine. Patients diagnosed with thoracolithiasis between January 2010 and December 2024 were reviewed retrospectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study population consisted of adult patients who presented to our hospital within the specified period and were found to have imaging findings compatible with thoracolithiasis on thoracic imaging, particularly thoracic computed tomography (CT). Cases diagnosed intraoperatively or confirmed pathologically were also included. Each patient was evaluated only once.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients were eligible for inclusion if they met the following criteria:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eAge ≥ 18 years,\u003c/li\u003e\n \u003cli\u003eDiagnosis of thoracolithiasis between January 2010 and December 2024,\u003c/li\u003e\n \u003cli\u003eDiagnosis confirmed radiologically (CT, chest X-ray) or surgically,\u003c/li\u003e\n \u003cli\u003eComplete availability of clinical records and imaging data,\u003c/li\u003e\n \u003cli\u003eAvailability of at least one sequential imaging study to assess nodule mobility was considered preferable, though not mandatory.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBoth asymptomatic, incidentally detected cases and patients evaluated due to symptoms during the diagnostic process were included.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients were excluded if any of the following applied:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eAge \u0026lt; 18 years,\u003c/li\u003e\n \u003cli\u003eInability to confirm the diagnosis radiologically or surgically,\u003c/li\u003e\n \u003cli\u003eMissing or inaccessible imaging (CT, X-ray) or clinical records,\u003c/li\u003e\n \u003cli\u003eCases in which thoracolithiasis remained only a suspected diagnosis and subsequent follow-up revealed an alternative pathology,\u003c/li\u003e\n \u003cli\u003eNodular calcifications clearly attributable to prior invasive pleural procedures (e.g. post–talc pleurodesis),\u003c/li\u003e\n \u003cli\u003eCalcified foci arising in the context of secondary malignant pleural disease (e.g. pleural metastases, mesothelioma),\u003c/li\u003e\n \u003cli\u003ePatients who were diagnosed at our center but followed exclusively at another institution, with insufficient clinical information available.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eData Collection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEligible cases were identified through retrospective searches of the hospital information system, picture archiving and communication system (PACS), operative reports, and the pathology database. Keywords used in the search included “thoracolithiasis”, “pleural loose body”, and “mobile pleural nodule”.\u003c/p\u003e\n\u003cp\u003eFor each patient, the following variables were collected:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003e\u003cstrong\u003eDemographic data:\u003c/strong\u003e age, sex, city of residence, year of presentation, primary reason for presentation\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eClinical data:\u003c/strong\u003e presence and type of symptoms, comorbidities, duration of follow-up\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eRadiologic data:\u003c/strong\u003e type of imaging modality, lesion localization, number of lesions, maximum diameter (mm), density (calcified vs non-calcified), mobility status, and other concomitant pleural or pulmonary findings\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIntervention data:\u003c/strong\u003e clinical follow-up vs surgical intervention (VATS / thoracotomy), type of surgical procedure, pathology result\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eDiagnostic process:\u003c/strong\u003e duration of pre-diagnostic follow-up, mode of diagnosis (radiologic vs surgical)\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAll data were anonymized and recorded in a Microsoft Excel spreadsheet. Imaging findings relevant to the diagnosis were reviewed independently by more than one investigator, and parameters such as mobility, density, and positional change were assessed by consensus.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLiterature Review\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA comparative literature review was also planned. For this purpose, a systematic search of PubMed and Scopus was performed using the keywords “thoracolithiasis”, “pleural loose body”, and “calcified mobile pleural nodule”. Published case reports and case series were identified, and their clinical, radiologic, and pathological findings were summarized and compared with the results of the present study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003cbr\u003eThis retrospective study was conducted in accordance with the ethical standards of the institutional and national research committees and with the 1964 Declaration of Helsinki and its later amendments. The study protocol was reviewed and approved by the \u003cstrong\u003eOndokuz Mayıs University Clinical Research Ethics Committee\u003c/strong\u003e (Approval No: \u003cstrong\u003e2025/239\u003c/strong\u003e\u003cstrong\u003e, \u003cstrong\u003eJune 2025\u003c/strong\u003e\u003c/strong\u003e). The requirement for informed consent was waived due to the retrospective nature of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSTATISTICAL ANALYSIS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll statistical analyses were performed using \u003cstrong\u003eIBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY, USA)\u003c/strong\u003e. Continuous variables were expressed as \u003cstrong\u003emean ± standard deviation (SD)\u003c/strong\u003e or \u003cstrong\u003emedian (interquartile range, IQR)\u003c/strong\u003e, as appropriate. Categorical variables were presented as \u003cstrong\u003enumbers and percentages [n (%)]\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eComparisons between two independent groups (e.g., male vs. female, symptomatic vs. asymptomatic, calcified vs. non-calcified) were performed using the \u003cstrong\u003eMann–Whitney U test\u003c/strong\u003e for continuous variables and the \u003cstrong\u003eChi-square or Fisher’s exact test\u003c/strong\u003e for categorical variables. A two-tailed \u003cstrong\u003ep-value \u0026lt; 0.05\u003c/strong\u003e was considered statistically significant.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eA total of 20 patients with pathologically confirmed thoracolithiasis were included in the study. The baseline demographic, clinical, radiologic, and surgical characteristics are summarized in \u003cstrong\u003eTable 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eRepresentative imaging example of non-mobile thoracolithiasis is shown in Figure 1.\u003c/p\u003e\n\u003cp\u003eMost patients were residents of Samsun province (12/20, 60%), while the remaining cases were referred from neighboring provinces (Amasya, Corum, Ordu, Tokat) and one patient from Baku, Azerbaijan.\u003c/p\u003e\n\u003cp\u003eMale and female patients demonstrated similar age, lesion size, and number of thoracoliths; however, significant sex-related differences were observed in smoking history and associated thoracic pathology, as detailed in \u003cstrong\u003eTable 2\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eSymptomatic and asymptomatic patients showed similar demographic and radiologic characteristics. Minor differences were observed in lesion laterality and detection mode, with symptomatic cases more often right sided and less frequently incidental (p = .0306 and p = .0036, respectively), although these findings had limited clinical significance.\u003c/p\u003e\n\u003cp\u003ePatients with calcified thoracoliths were significantly older than those with non-calcified lesions (70.0 ± 7.4 vs 60.0 ± 10.7 years, p = .0227). No significant differences were observed in lesion size, symptom status, smoking history, or associated thoracic pathology between the two groups.\u003c/p\u003e\n\u003cp\u003ePatients with coexisting lung cancer were predominantly older male smokers, showing a trend toward higher age compared to those without cancer (69.4 ± 8.2 vs 60.4 ± 10.9 years, p = .0585). The presence of lung cancer was significantly associated with male sex (p = .010) and smoking history (p = .027), while other clinical and radiologic features were comparable between groups.\u003c/p\u003e\n\u003cp\u003ePatients were classified as having \u003cstrong\u003eisolated\u003c/strong\u003ethoracolithiasis when no concomitant thoracic disease was present, and as \u003cstrong\u003esecondary\u003c/strong\u003ewhen thoracolithiasis coexisted with lung cancer or other thoracic pathology.\u003cbr\u003eCompared with secondary cases, isolated thoracolithiasis was more common in female non-smokers and was predominantly managed by diagnostic exploration (\u003cstrong\u003eTable 3\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003eTo explore potential environmental contributors, patients were stratified according to a history of asbestos exposure (5/20, 25%). Asbestos-exposed patients were slightly older on average, and a striking geographic clustering was observed: all exposed patients originated from inland provinces (Amasya, Corum, Tokat), whereas almost all non-exposed patients resided in Samsun (p = .0004). Coronary artery disease (80.0% vs 6.7%, p = .0049) and hypothyroidism (60.0% vs 0.0%, p = .0088) were also more frequent in the asbestos-exposed group, although the small sample size limits interpretation. In contrast, asbestos exposure was not clearly associated with lung cancer (20.0% vs 46.7%, p \u0026gt; .05) or with differences in symptomatology, lesion size, density, or timing of diagnosis.\u003c/p\u003e\n\u003cp\u003eThoracolithiasis was identified preoperatively in 35% of patients and intraoperatively in 65%. Patients with preoperative diagnosis were significantly older (69.9 vs 60.8 years, p = .0294), whereas intraoperative detection was more often associated with larger lesions and diagnostic explorations.\u003c/p\u003e\n\u003cp\u003eRepresentative intraoperative and postoperative findings of an isolated, non-malignant thoracolithiasis case are shown in Figure 2a–c, demonstrating the characteristic gross morphology of the thoracolith, the single-port VATS incision used for removal, and the postoperative chest radiograph confirming full re-expansion of the lung without residual pathology.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis single-center 20-patient series adds several important observations to the limited thoracolithiasis literature. First, all lesions in our cohort were non-mobile, in contrast to the traditional description of thoracolithiasis as a freely mobile pleural loose body [1, 3]. Second, we demonstrate that thoracolithiasis is not a uniform entity but appears to segregate into two distinct etiologic phenotypes: a\u0026nbsp;secondary, male, smoker, cancer-associated type\u0026nbsp;and an\u0026nbsp;isolated, female, non-smoker type. Notably, these patterns also demonstrated a geographic dimension, with isolated cases predominantly occurring in patients residing in non–asbestos-endemic areas, whereas asbestos-exposed patients originated exclusively from inland provinces known for environmental exposure.\u0026nbsp;Third, we show that isolated non-mobile thoracoliths are particularly prone to misdiagnosis as malignant pleural nodules, resulting in a high rate of unnecessary exploratory surgery.\u003c/p\u003e\n\u003cp\u003ePrevious CT-based series and narrative reviews have emphasized three main features of classic thoracolithiasis: rarity, left-sided predominance, and mobility [1, 3, 6]. Kinoshita et al. described 11 cases of calcified intrapleural loose bodies, most located in the left lower hemithorax and all demonstrating mobility on serial imaging [3] Strzelczyk et al. referred to these lesions as “rolling stones in the pleural space” and proposed that positional change on CT is a key diagnostic criterion [1]. Similarly, Suwatanapongched et al. reported thin-section CT findings in nine patients and confirmed the typical left lower hemithorax distribution, ovoid morphology, and frequent calcification [6]. Gayer also highlighted mobility and laminated internal architecture as important clues to the diagnosis [5].\u003c/p\u003e\n\u003cp\u003eIn contrast, our series shows a more balanced laterality (right 50%, left 45%) and, importantly, no radiologic or intraoperative mobility in any case. This pattern aligns more closely with recent case reports describing immobile thoracolithiasis anchored to pleural fat or presenting as pedunculated-appearing pleural masses, which challenge the classical notion that mobility is obligatory for diagnosis [7-9]. Our data suggest that non-mobile thoracolithiasis may be under-recognized and under-reported, particularly when coexisting with other thoracic pathology.\u003c/p\u003e\n\u003cp\u003eA growing number of reports document atypical thoracoliths that mimic pleural plaques, metastases, or even primary malignancies [7, 10, 11]. Cha et al. described thoracolithiasis simulating an asbestos-related pleural plaque in an asbestos-exposed patient [7]. Bolca et al. reported a pearl-like thoracolith that closely resembled a pleural or mediastinal tumor [10]. Wong et al. recently published a case of thoracolith mimicking pulmonary osteosarcoma metastasis, emphasizing the risk of over-treating this benign entity [11]. Our isolated, non-mobile, mostly non-calcified lesions fit well within this emerging spectrum of “malignancy mimics”. Notably, in our cohort, these atypical presentations clustered among patients residing in non–asbestos-endemic coastal regions, whereas asbestos-exposed individuals originated exclusively from inland provinces. This geographic separation suggests that environmental background may influence both the radiologic appearance and diagnostic ambiguity of thoracolithiasis, further complicating distinction from malignant pleural disease.\u003c/p\u003e\n\u003cp\u003eIn our cohort, all six isolated thoracolithiasis cases occurred in non-smoking or low-risk women without coexisting thoracic disease, yet 100% of these patients underwent diagnostic exploratory surgery because malignancy could not be confidently excluded preoperatively. This finding parallels prior reports in which immobile or atypical thoracoliths were only diagnosed definitively at thoracoscopy or thoracotomy [10, 12, 13]. These observations underscore the need to broaden the radiologic and clinical definition of thoracolithiasis beyond the classical mobile, calcified nodule.\u003c/p\u003e\n\u003cp\u003eConsistent with previous series, most of our patients were asymptomatic, and symptom presence did not correlate with lesion size or calcification [1, 2, 14]. Kang et al. and others have reported that symptoms, when present, tend to occur in patients with multiple or larger thoracoliths and often improve after surgical removal [14, 15]. In our series, however, symptomatic cases were defined by a combination of clinical judgement and exclusion of alternative causes, which may partly explain the absence of a clear size–symptom relationship.\u003c/p\u003e\n\u003cp\u003eMore intriguingly, we found that symptoms were associated with right-sided location and a borderline association with prior tuberculosis. This pattern supports the hypothesis that chronic pleural inflammation—whether due to prior infection or other inflammatory processes—may contribute both to thoracolith formation and to pleuritic pain or cough by altering local pleural mechanics. Similar associations between thoracolithiasis, prior infection, and pleural adhesions have been noted in individual case reports [15, 16]. While causality cannot be established in our small sample, these findings align with one of the major proposed pathogenetic pathways: post-inflammatory organization and detachment of necrotic pleural or pericardial fat [2, 12, 17].\u003c/p\u003e\n\u003cp\u003eThe observed association between calcification and older age in our cohort (70 vs 60 years) supports a time-dependent, degenerative model of thoracolith evolution. Early-stage lesions may be non-calcified, composed primarily of necrotic fat and fibrous tissue, and only gradually develop calcifications over years. This concept is in line with histopathologic descriptions in prior series, where centrally necrotic fat cores showed increasing fibrosis and calcification over time [13, 18]. Our finding that symptom status and lesion size do not differ between calcified and non-calcified groups further suggests that calcification is a\u0026nbsp;marker of chronicity rather than clinical aggressiveness.\u003c/p\u003e\n\u003cp\u003eFrom a radiologic perspective, however, calcification may be a useful clue favoring thoracolithiasis over malignant disease, especially when combined with peripheral pleural location and stability over time [3, 5]. Non-calcified lesions, in contrast, may be more easily mistaken for malignant nodules, particularly when non-mobile and isolated.\u0026nbsp;\u003cstrong\u003eIndeed, in our cohort, the majority of unnecessary surgical explorations were performed for these non-calcified thoracoliths, as their radiologic appearance frequently mimicked malignancy and raised concern for occult metastatic or primary disease.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe high proportion of patients with coexisting lung cancer in our cohort (40%), all male smokers, indicates that thoracolithiasis may frequently arise in the context of chronic smoking-related and malignant pleural inflammation. Prior CT series and case reports have noted coexisting pulmonary or pleural disease in a substantial subset of thoracolithiasis patients, including emphysema, prior surgery, or malignancy [3, 5, 6]. Our data extend these observations by demonstrating a clear sex- and smoking-linked phenotype:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eSecondary thoracolithiasis\u0026nbsp;in older male smokers with thoracic malignancy or other significant pathology, versus\u003c/li\u003e\n \u003cli\u003eIsolated thoracolithiasis\u0026nbsp;in younger or middle-aged non-smoking women without malignancy.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn practical terms, this dichotomy has important implications:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eIn \u003cstrong\u003ehigh-risk\u003c/strong\u003e patients (older male smokers with lung cancer), thoracoliths are usually discovered incidentally during oncologic work-up or surgery and rarely influence management.\u003c/li\u003e\n \u003cli\u003eIn \u003cstrong\u003elow-risk\u003c/strong\u003e patients (non-smoking women without cancer), non-mobile thoracoliths are more likely to be interpreted as primary malignant pleural nodules, triggering decision-making cascades that end in diagnostic thoracoscopy or thoracotomy.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eTaken together, our findings—supported by recent literature—suggest that the diagnostic concept of thoracolithiasis should be expanded along two axes:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n \u003cli\u003e\u003cstrong\u003eMobility spectrum:\u003c/strong\u003e Thoracoliths may range from freely mobile to partially adherent to fully immobile, particularly when anchored to pleural fat or in the setting of pleural adhesions [7-9].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eEtiologic spectrum:\u003c/strong\u003e Thoracolithiasis may represent either an isolated degenerative process in otherwise healthy pleura or a secondary sequel of chronic inflammatory or malignant pleural disease [3, 12, 17].\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eFor radiologists and clinicians, several practical points emerge:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eNon-mobile, pleural-based nodules in low-risk patients—especially non-smoking women without other suspicious findings—should prompt consideration of\u0026nbsp;non-mobile thoracolithiasis\u0026nbsp;in the differential diagnosis, even in the absence of demonstrated mobility.\u003c/li\u003e\n \u003cli\u003eReview of prior imaging for subtle change in position, careful assessment of the pleural–parenchymal interface, and attention to fatty or laminated internal structure may provide additional clues [5, 11].\u003c/li\u003e\n \u003cli\u003eWhen thoracolithiasis is strongly suspected and malignancy risk is otherwise low, short-interval imaging follow-up rather than immediate diagnostic thoracoscopy may be reasonable, although this approach requires validation in larger cohorts.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThis study has several limitations. It is a single-center, retrospective series with a small sample size (N = 20), which limits statistical power and generalizability. Confidence intervals are wide, and several clinically relevant associations (e.g. tuberculosis history and symptoms, lung cancer and age, lesion size and diagnostic timing) approached but did not reach conventional statistical significance. As our series includes only non-mobile lesions, direct comparison with mobile thoracolithiasis was not possible. Finally, referral and selection bias are likely, as all patients ultimately underwent surgery, potentially over-representing diagnostically challenging or symptomatic cases.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eIn this 20-patient series, thoracolithiasis presented exclusively as\u0026nbsp;non-mobile pleural nodules, challenging the traditional view that mobility is a mandatory diagnostic feature. Our data support the existence of two distinct clinical–etiologic profiles:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n \u003cli\u003eA \u003cstrong\u003esecondary type\u003c/strong\u003e, occurring predominantly in older male smokers with lung cancer or other significant thoracic pathology; and\u003c/li\u003e\n \u003cli\u003eAn \u003cstrong\u003eisolated type\u003c/strong\u003e, seen mainly in non-smoking women without additional thoracic disease, in whom non-mobile thoracoliths frequently mimicked malignant pleural nodules and led to unnecessary diagnostic exploration.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eCalcification was associated with older age, consistent with a time-dependent degenerative process, whereas symptomatology appeared more closely related to side (right hemithorax) and prior tuberculosis than to lesion size or density. Recognition that thoracolithiasis may be\u0026nbsp;non-mobile, non-calcified, and isolated—particularly in low-risk patients—is crucial to avoid misdiagnosis and potentially prevent avoidable invasive procedures.\u003c/p\u003e\n\u003cp\u003eFuture multicenter studies with larger cohorts, including both mobile and non-mobile lesions, are needed to refine diagnostic criteria and to develop evidence-based management strategies for this rare but clinically relevant pleural entity.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eDisclosures:\u003c/strong\u003e All authors have nothing to disclose\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e The authors received no financial support for this article's research, authorship, and/or publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest/Competing interests\u003c/strong\u003e: The authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material:\u003c/strong\u003e The data supporting this study's findings are available from the corresponding author upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e: The study was conducted with the approval of the Ondokuz University Clinical Research Ethics Committee (Decision no: \u003cstrong\u003e2025/239,\u0026nbsp;\u003c/strong\u003eApproval date: 26/06/2025).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed Consent Statement:\u0026nbsp;\u003c/strong\u003eAll participants gave written informed consent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e Conception and design of the work, supervision, and manuscript drafting: C.İ., M.G.P., B.C.Ö.; Data collection, analysis, and interpretation of the data: M.G.P., B.C.Ö., H.K., B.Ç., Y.B.B.; Statistical analysis: C.İ., H.K.; Critical manuscript revision: all authors. Approval of the final manuscript: all authors.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eStrzelczyk J, et al. Rolling stones in the pleural space: thoracoliths on CT, and a review of the literature. Clin Radiol. 2009;64(1):100\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeungjesada S, Gupta P, Mottershaw A. Thoracolithiasis: a case report. Clin Imaging. 2012;36(3):228\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKinoshita F, et al. Thoracolithiasis: 11 cases with a calcified intrapleural loose body. J Thorac Imaging. 2010;25:64\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIwasaki T, et al. Surgically removed thoracolithiasis: report of two cases. Ann Thorac Cardiovasc Surg. 2006;12(4):279\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGayer G. Thoracolithiasis\u0026mdash;computed tomography findings of intrapleural loose bodies. Semin Ultrasound CT MR. 2017;38(6):634\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuwatanapongched T, Nitiwarangkul C. Thin-section CT findings of thoracolithiasis. Jpn J Radiol. 2017;35:350\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCha YK, et al. Thoracolithiasis mimicking a pleural plaque in a patient with a history of asbestos exposure: a case report. J Korean Soc Radiol. 2017;77:245\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim S, et al. Clinical, electrodiagnostic and imaging features of true neurogenic thoracic outlet syndrome: experience at a tertiary referral center. J Neurol Sci. 2019;404:115\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamamoto N, Onoda K. Thoracolithiasis: a rare pearl earring-like lesion. Indian J Thorac Cardiovasc Surg. 2024;40(4):497\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBolca C, Trahan S, Fr\u0026eacute;chette \u0026Eacute;. Intrapleural thoracolithiasis: a rare intrathoracic pearl-like lesion. Thorac Cardiovasc Surg. 2011;59:445\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWong M et al. Thoracolith mimicking pulmonary osteosarcoma metastasis. J Radiol Case Rep. 2024.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKataoka K, et al. Thoracoscopically removed thoracolithiasis. Kyobu Geka. 2010;63(12):1066\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKomatsu T, Sowa T, Fujinaga T. A case of thoracolithiasis diagnosed thoracoscopically. Int J Surg Case Rep. 2012;3(9):415\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKang N, et al. A rare case of numerous thoracolithiasis with chest discomfort. Respir Med Case Rep. 2018;25:264\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHsu F, Huang TS, Pu TW. Formation of a rare curve-shaped thoracolith documented on serial chest computed tomography images: a case report. World J Clin Cases. 2023;11:2329\u0026ndash;35.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTsuchiya T, et al. A case of migrated thoracolithiasis. J Thorac Imaging. 2009;24(4):325\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKosaka S, et al. Thoracolithiasis Jpn J Thorac Cardiovasc Surg. 2000;48(5):318\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOgushi A, Sugioka T, Nishiyama M, Thoracolithiasis. J Gen Fam Med. 2019;20:122\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Baseline demographic, clinical, radiologic, and surgical characteristics of patients with thoracolithiasis (N = 20)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003en (%) / Mean\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e± SD\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e64.0\u0026nbsp;±\u0026nbsp;10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Male\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14 (70)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Female\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (30)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLaterality\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Right\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Left\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (45)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Bilateral\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLesion characteristics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean maximum diameter (mm)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e29.4 ± 17.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean number per patient\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.2 ± 0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCalcified\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (40.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eNon-calcified\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (60.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMobile\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAssociated thoracic pathology\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Lung cancer\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (40.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Other thoracic disease\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; None\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eClinical presentation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSymptomatic (chest pain, cough, dyspnea)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (25.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Asymptomatic / incidental\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (60.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Not recorded\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (15.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSmoking history\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Active or former smoker\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15 (75.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Non-smoker\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (25.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSurgical approach\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;VATS\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14 (70.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Thoracotomy\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ePrimary surgical indication\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Diagnostic exploration\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10 (50.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Lobectomy\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (35.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Wedge resection\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (15.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eData are presented as mean ± SD or n (%).\u003cstrong\u003e\u003csup\u003e\u0026nbsp;a\u003c/sup\u003eSD:\u003c/strong\u003e Standard Deviation; \u003cstrong\u003e\u003csup\u003eb\u003c/sup\u003eVATS:\u003c/strong\u003e Video-Assisted Thoracoscopic Surgery\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e Comparison of demographic, clinical, radiologic, and surgical characteristics according to sex\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eMale (n=14)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eFemale (n=6)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e(years, mean ± SD\u003csup\u003ea\u003c/sup\u003e)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e66.1 ± 9.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e59.0 ± 11.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.212\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLesion size (mm, mean ± SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e30.2 ± 18.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e27.5 ± 16.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.758\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eNumber of thoracoliths (mean ± SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.3 ± 0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.0 ± 0.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.480\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSmoking history\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e14 (100 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (16.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.00038\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLung cancer\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (57.1 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.018\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eNo associated thoracic disease\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (14.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (66.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.022\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eData are presented as mean ± SD or n (%).\u003cstrong\u003e\u003csup\u003e\u0026nbsp;a\u003c/sup\u003eSD:\u003c/strong\u003e Standard Deviation\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Comparison of demographic, clinical, radiologic, and surgical characteristics between isolated and secondary thoracolithiasis\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIsolated (n = 6)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSecondary (n = 14)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e(years, mean ± SD\u003csup\u003ea\u003c/sup\u003e)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e61.5 ± 9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e65.3 ± 10.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.431\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex (male)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (33.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (85.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.0374\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSmoking history (active/former)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (33.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13 (92.9 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.0139\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLesion size (mm, mean ± SD)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e33.3 ± 18.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e27.7 ± 17.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.471\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCalcified lesion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (16.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (50.0 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.197\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSymptomatic presentation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (33.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3 (21.4 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.598\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSurgical procedure\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Diagnostic exploration\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (100 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (35.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.0253\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Lobectomy\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7 (50.0 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Wedge resection\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (14.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eTiming of diagnosis\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Preoperative\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (16.7 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (42.9 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e.291\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp;Intraoperative\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5 (83.3 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8 (57.1 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eData are presented as mean ± SD or n (%).\u003cstrong\u003e\u003csup\u003e\u0026nbsp;a\u003c/sup\u003eSD:\u003c/strong\u003e Standard Deviation\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-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Thoracolithiasis, pleural loose body, non-mobile thoracolith, pleural nodule, VATS","lastPublishedDoi":"10.21203/rs.3.rs-8314067/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8314067/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eThoracolithiasis is a rare benign pleural condition classically described as a freely mobile, calcified intrapleural loose body. Systematic data on non-mobile thoracolithiasis and its clinical context are scarce. This study aimed to characterize the clinical, radiologic, etiologic, and geographic features of non-mobile thoracolithiasis, to explore isolated versus secondary (malignancy-associated) forms, and to identify scenarios in which these lesions mimic malignant pleural nodules.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eThis retrospective, observational study included adult patients diagnosed with thoracolithiasis at a tertiary thoracic surgery center between January 2010 and December 2024. Eligible cases had radiologic and/or surgical confirmation and complete clinical and imaging data. Demographic, clinical, radiologic, and surgical variables, including asbestos exposure and coexisting thoracic disease, were collected. Patients were stratified by sex, symptom status, calcification, and isolated versus secondary thoracolithiasis. Statistical comparisons used the Mann\u0026ndash;Whitney U test and Chi-square or Fisher\u0026rsquo;s exact test (two-tailed p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). A comparative literature review of PubMed and Scopus was performed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTwenty patients with pathologically confirmed thoracolithiasis (mean age 64.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.5 years; 70% male; 75% ever-smokers) were included. All lesions were non-mobile; 60% were non-calcified, with a mean maximum diameter of 29.4\u0026thinsp;\u0026plusmn;\u0026thinsp;17.8 mm. Thoracolithiasis coexisted with lung cancer in 40% and with other thoracic disease in 30%; 30% were isolated. Patients with calcified lesions were older than those with non-calcified lesions (70.0 vs 60.0 years, p\u0026thinsp;=\u0026thinsp;0.0227). Lung cancer occurred exclusively in older male smokers and was associated with male sex (p\u0026thinsp;=\u0026thinsp;0.010) and smoking history (p\u0026thinsp;=\u0026thinsp;0.027). Isolated thoracolithiasis was more frequent in female non-smokers, and all isolated cases underwent diagnostic exploration (100% vs 35.7%, p\u0026thinsp;=\u0026thinsp;0.0253). Asbestos-exposed patients (25%) originated exclusively from inland provinces, whereas most non-exposed patients resided in a coastal, non\u0026ndash;asbestos-endemic region.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eNon-mobile thoracolithiasis exhibits two distinct clinical\u0026ndash;etiologic profiles: a secondary type in older male smokers with thoracic malignancy, and an isolated type in non-smoking women without additional thoracic disease. Non-mobile, often non-calcified thoracoliths in low-risk patients frequently mimic malignant pleural nodules and may lead to avoidable thoracoscopic or open exploration. Recognizing this broader spectrum of thoracolithiasis may help refine diagnostic algorithms and reduce unnecessary invasive procedures.\u003c/p\u003e","manuscriptTitle":"Thoracolithiasis: A Rare and Frequently Underrecognized Entity – A Retrospective Single- Center Study and Comprehensive Literature Review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-12 06:13:19","doi":"10.21203/rs.3.rs-8314067/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-12T17:38:59+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-17T20:26:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-11T09:12:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"47553444387617056908303066681542454118","date":"2026-01-07T11:37:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250853819083688900691374216855874795641","date":"2026-01-07T11:32:19+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-07T11:00:34+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-12-11T15:51:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-11T10:05:22+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-12-11T10:03:14+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Surgery","date":"2025-12-09T06:38:53+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"91da8a18-84fb-4486-9182-308035f421a4","owner":[],"postedDate":"January 12th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-17T15:25:51+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-12 06:13:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8314067","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8314067","identity":"rs-8314067","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}