Effusion cytology of epithelioid rhabdomyosarcoma.

We report a case of epithelioid rhabdomyosarcoma in a pleural effusion. In contrast to most rhabdomyosarcomas in effusions, the cells presented as cohesive clusters of atypical cells with abundant eosinophilic cytoplasm which mimicked an adenocarcinoma. Immunohistochemistry was positive for epithelial membrane antigen and muscle markers and negative for keratins.