Urogenital involvement by desmoplastic small round-cell tumor

Purpose: We strove to characterize the clinicopathologic features of a rare malignant tumor involving the urogenital system. Materials and Methods: Of 109 reported cases of desmoplastic small round-cell tumor, 25 have involved organs ordinarily evaluated and treated by urologists. Experience based on these cases plus 2 from our files forms the basis of this review. Results: The term desmoplastic small round-cell tumor has been applied to a rare, highly malignant neoplasm that occurs most often in the abdominal cavity and is described in the nonurological literature. This cancer has distinctive histological, immunohistochemical and ultrastructural features. Several reports suggest a characteristic genetic abnormality. All reported patients who have tumors involving the genitourinary structures have been treated with chemotherapy, but prognosis has been poor. Conclusions: The literature on desmoplastic small round-cell tumor indicates that a significant percentage of these rare malignancies involve genitourinary organs. In most cases, tumors have been unresectable surgically and treatment has been multidrug chemotherapy. Response to treatment has been poor, with only 3 of 25 determinate cases free of disease when reported.