Diagnosis of desmoplastic small‐round‐cell tumor by cytogenetic analysis: a case report

Desmoplastic small‐round‐cell tumor (DSRCT) is a rare, highly aggressive intra‐abdominal neoplasm with an extremely poor prognosis, first described in 1989 1. It frequently occurs in the abdominal cavity and pelvis with an undetermined histologic origin, and its incidence in males (>80%) and females differs 2, 3, 4, 5, 6. In one comprehensive study, the typical immunohistochemical features were epithelial marker positivity (cytokeratin, 91%; epithelial membrane antigen [EMA], 88%), mesenchymal marker positivity (desmin, 91%; vimentin, 84%), and various results for neural antigens 6. Atypical histologic and immunohistochemical features can pose a diagnostic dilemma. We herein report a case of epithelial marker – negative DSRCT, only a few cases of which have been reported worldwide. Cytogenetic profiles could provide useful diagnostic information in such cases.