Bladder carcinosarcoma: histologic variation in metastatic lesions.

Carcinosarcoma is a tumor composed of malignant epithelial and mesenchymal elements, which occurs rarely in the bladder. Although the prognosis of bladder carcinosarcoma is known to be poor the histology of metastatic lesions is not well described. We report 2 cases of bladder carcinosarcoma with pelvic lymph node involvement. Pure sarcomatous metastasis was present in 1 patient and only carcinoma in the other. The histologic composition of metastatic lesions may be of significance in treatment planning in patients with bladder carcinosarcoma.