Malignant phyllodes tumor of the prostate

Phyllodes tumor of the prostate is rare. We have recently experienced a cas e of phyllodes tumor of the prostate in a 57-year-old man who complained of urinary retention for 1 year. The epithelial components were positive reac tivity for prostate specific antigen. The stromal cells showed nuclear atyp ia with increased mitotic activity. The tumor was diagnosed as a malignant phyllodes tumor as it invaded into the urinary bladder and rectum, and grew rapidly immediately after operation. We describe the morphological feature s and immunohistochemical findings of malignant phyllodes tumor and review the literature.