A 15-year-old with molecularly confirmed sarcoma with BCOR genetic alterations and aberrant positive panTRK immunohistochemistry, a case review

Sarcomas with BCOR genetic alterations are a group of rare, recently described, primitive round cell sarcomas that result in oncogenic activation and overexpression of BCOR. 1 We describe a case of a 15-year-old male presenting with spinal cord displacement and compression; the result of a sarcoma with molecularly confirmed BCOR::CCNB3 gene fusion. His sarcoma falsely expressed panTRK immunohistochemistry without a corresponding TRK molecular alteration, an immunohistochemical profile uncommonly described in literature. 2 In this case review we examine clinical behaviour, morphological spectrum and differential diagnosis for this rare entity.