RESUMEN
OBJECTIVE: To report a rare case of primary round cell liposarcoma of the urinary bladder. METHODS: A case of primary round cell liposarcoma of the urinary bladder in an 80-year-old female with hematuria is presented. The patient had a large, solid, non-circumscribed bladder tumor of 6.5 cms. The radiological, histological and immunohistochemical findings are discussed. RESULTS: The neoplasm was composed of isolated lipoblasts among numerous small round cells that were positive for S-100 and vimentin, and a high proliferation rate was demonstrated by Ki-67. The patient died 10 months after the histologic diagnosis. CONCLUSION: Primary liposarcoma of the urinary bladder is a very rare tumor with a poor prognosis that usually presents as a large tumor mass.
