Carcinosarcoma of prostate. Immunohistochemical and ultrastructural observations

Carcinosarcoma of the prostate is a most uncommon disease, and only a few cases have been reported previously. We report the clinical and histopathologic findings in a seventy-three-year-old man with a prostatic carcinosarcoma. The mesenchymal component of the tumor was classified as malignant fibrous histiocytoma (MFH) by electron microscopy and immunohistochemical staining methods. This is to our knowledge the first case in which the stromal component of a prostatic carcinosarcoma has been classified as MFH.