Prevalence of Soft Tissue and Bone Tumor Diagnostic Discrepancies from Initial to Referral Sarcoma Center

Objective: Diagnosing sarcoma can be challenging. This study evaluates pathological reviews of all sarcoma cases diagnosed at Siriraj Hospital, comparing initial diagnoses with those confirmed by a dedicated sarcoma pathologist Materials and Methods: Histopathological data from sarcoma patients at Siriraj Hospital were collected over five years. Initial diagnoses were compared to those determined by specialized sarcoma pathologists. Results: Among the 185 patients, 107 (57%) met the inclusion criteria and were then analyzed. Full concordance (perfect agreement between initial and sarcoma specialized pathologist) was observed in 28 (26.1%) cases, partial concordance (identical diagnosis with differences in classification and / or histopathological subtype differences) in 18 (16.8%) cases, and zero concordance (benign to malignant or vice versa, different histopathological type or invalidation of sarcoma diagnosis) in 61 (57%) cases. The rate of complete concordance was significantly higher in cases with initial complete immunohistochemical (IHC) studies (HR 4.17 and 95% CI 1.43-12.12; p = 0.009), tumors size 100 mm or more (HR 0.32 and 95% CI 0.10-0.99; p = 0.04) and younger than 18 years (HR 5.48, 95% CI 1.49-20; p = 0.01). The main discrepancies were histopathological type (n = 53, 49.5%), subtype (n = 8, 7.5%) and grade plus subtype (n = 4, 3.7%). The mean duration from diagnosis to treatment was 68 days (range: 0-272). Conclusion: The second opinion modified 73.8% of the initial diagnoses. However, no significant association was found between concordance of diagnosis and time to treatment initiation. Second opinion improves diagnostic accuracy and potentially enhance patient care.