Sarcomatoid carcinoma of the urinary tract

Sarcomatoid carcinoma is a rare variant of malignant tumor arising from the urinary tract. This tumor had been termed carcinosarcoma because of its carcinomatous and sarcomatous components. There is still some confusion in the terminology between true carcinosarcoma and sarcomatoid carcinoma; however, the latter is now regarded as primarily a malignant epithelial tumor with pseudosarcomatous transformation. Four cases of sarcomatoid carcinoma arising from the urinary tract are reported. The patients were a 77 year old female, and three males aged 62, 69 and 80 years. All but the eldest patient complained of gross hematuria. Surgical removal was performed in the younger three cases, and an autopsy was done in the remaining case. All the tumors were macroscopically polypoid. Histopathologic examination revealed fasciculated spindle-cell tumors with myxoid stroma or malignant fibrous histiocytoma-like spindle cell tumors. The epithelial nature was proven in these sarcomatous cells by immunohistochemical and/or electron-microscopic examinations. Only a small amount of squamous cell carcinoma components was also evident in the latter three cases. Although the younger three patients were alive at 44, 23 and 39 months' follow-up, respectively, constant careful monitoring is recommended.