BCOR upregulation in a poorly differentiated synovial sarcoma with SS18L1-SSX1 fusion-A pathologic and molecular pitfall.

ABSTRACT: The diagnosis of poorly differentiated synovial sarcoma (PD-SS) may be challenging due to overlapping morphologic features with other undifferentiated round cell sarcomas (URCS). Particularly relevant is the histologic overlap and shared BCOR overexpression between a subset of SS and URCS with various BCOR genetic abnormalities. Here, we report a case of PD-SS lacking the canonical SS18-SSX gene fusion, but showing strong BCOR immunoreactivity and BCOR gene abnormalities by FISH, which were misinterpreted as a URCS with BCOR gene rearrangements. The tumor had an unusual clinical presentation arising as an intraneural tumor in the ankle of a 29-year-old female. The tumor displayed a mixture of fascicular spindle cells and undifferentiated round cell components. FISH studies showed no SS18 g

SUBMITTER: Kao YC 

PROVIDER: S-EPMC5546405 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature