Prostatic embryonal rhabdomyosarcoma in adults. A clinicopathologic review.

Embryonal rhabdomyosarcoma of the prostate is a rare, highly malignant tumor that occurs predominantly in male infants and children, in whom it is the most common prostatic sarcoma. Six cases occurring in adults have been published, and the authors report three additional cases. The natural history is characterized by rapid growth, with the typical formation of large pelvic or abdominal masses, often leading renal failure due to bilateral ureteric obstruction. The tumor eventually disseminates widely, mainly to the lungs, bone, liver, and serosal surfaces, and unlike most other sarcomas, regional lymph node metastases are common. Combined modality therapy has resulted in marked improvement in survival rates and reduced surgical morbidity for children with these tumors. However, in adults the prognosis remains poor, with all patients dying of disseminated disease within 16 months of histologic diagnosis (mean survival, 8 months).