ALVEOLAR RHABDOMYOSARCOMA - DEMONSTRATION OF THE MUSCLE TYPE OF INTERMEDIATE FILAMENT PROTEIN, DESMIN, AS A DIAGNOSTIC-AID

Abstract

Three human cases of soft-tissue sarcomas with the characteristic histologic features of alveolar rhabdomyosarcoma, but lacking cytoplasmic cross-striations, were studied ultrastructurally and immunohistochemically to confirm the diagnosis and evaluate the histogenesis. It was not possible to judge the skeletal muscle derivation of the cells at the ultrastructural level. Immunohistochemically, the results of every case were positive for desmin-the muscle type of the intermediate filament protein. Demonstration of desmin may be a helpful adjunct tool in the diagnosis of poorly differentiated alveolar rhabdomyosarcomas.