Discordance of histo-pathological diagnosis of patients with soft tissue sarcoma referred to tertiary care center.

Abstract

11064 Background: Reaching to the correct histo-pathological diagnosis of soft tissue sarcomas (STS) is a great challenge and is cornerstone for treatment planning. Need of expertise for diagnosis is limited by lack of expert pathologists and dedicated sarcoma oncologists in India. Through this study we highlight the pattern of pathological diagnosis and accuracy outside specialist centre. Methods: We did retrospective analysis of all patients referred to us with diagnosis of STS in the last 12 months (January 2016 to 2017). According to protocol, all patients had pathology review from our institute. If blocks were available then they were reviewed and if necessary, fresh biopsy was performed. Besides, pathological diagnosis was reviewed in joint clinic, giving clinico-radiological inputs to sarcoma pathologists. For patients diagnosed outside and had discordant report, we divided them into major discrepancy (including change of diagnosis of sarcoma to benign or other histological entity that could potentially change the treatment plan) or minor discrepancy (like mild change in grade or histopathological diagnosis not affecting the treatment plan). Results: There were 149 patients registered with median age of 36 years (14-77 years) and 93 patients (62.4%) were males. 85(57%) patients had localized disease. Most common subtypes were synovial sarcoma 16%, liposarcoma 9%, soft tissue ewings sarcoma 9%, MPNST 9%, leiomyosarcoma 8%, pleomorphic undifferentiated sarcoma 8% etc. Of 149 patients, 42 had not been worked up outside and thus comparison was not possible while 4 patients couldn’t retrieve blocks and repeat biopsy could not be performed. Of 97 patients (biopsy = 84, FNAC = 13) who had diagnosis from outside, 37% had major discrepancy and 24% had minor discrepancy compared with our biopsy review. Major discrepancy was more in non extremity than extremity STS (p = 0.003). Conclusions: Pathological diagnosis of more than half of patients referred from outside was discordant with respect to diagnosis of our centre with major implications on 37%. We believe this is due to lack of sarcoma pathology experts and virtually non-existent multidisciplinary clinics in set up outside tertiary care centres.