Intra-abdominal embryonal rhabdomyosarcoma in an adult

Rhabdomyosarcoma is an uncommon neoplasm in the adult population. Sporadic cases of primary rhabdomyosarcoma arising in the abdomen have been reported , but these cases are limited almost exclusively to the pediatric populatio n. We report a well-documented case of primary intra-abdominal rhabdomyosar coma in a 57-year-old woman. The patient presented with a pelvic mass and a n elevated serum CA 125 and was referred to gynecologic oncologists at our institution for a presumed primary gynecologic malignancy. Intraoperatively , amorphous gelatinous tumor comprised a large portion of the peritoneal ca vity. Surgical exploration of the abdomen failed to implicate any specific organ as the site of origin of the tumor. The overall histologic pattern of the resected tumor was most consistent with embryonal type rhabdomyosarcom a. To our knowledge this is the first well-documented case report of non-he patobiliary, adult, intra-abdominal embryonal rhabdomyosarcoma in the Engli sh language literature. The presentation of a rare adult sarcoma mimicking a gynecologic malignancy was an unusual feature that complicated the diagno sis in this case. (C) 1999 Academic Press.