[Carcinosarcoma of the prostate. Immunophenotype, morphologic course and clinico-pathologic differential diagnosis].

The observation of a patient with a malignant tumor of the prostate initially classified as adenocarcinoma with desmoplasia, reclassified as adenocarcinoma with a malignant spindle cell component of uncertain cell line following two large tumor recurrences over a period of 4 months, and subsequently as carcinosarcoma with heterologous mesenchymal areas has prompted us to review the 11 reported cases of prostatic carcinosarcoma and the diagnostic algorithm of the proliferative processes of the prostate with elongated cells in order to recognize (from the histological features and the inclusion and exclusion immunophenotypes) the pseudosarcomatous stromal reactions, fusicellular changes of the carcinoma, benign and malignant phyllodes tumors and carcinosarcoma.