Cystosarcoma phyllodes of the prostate with rhabdomyoblastic differentiation

A 36-year-old man presented with recurrent urinary obstruction and an enlar ged, partially cystic prostate tumour on ultrasonography. Microscopically, the tumour was composed of cystically dilated ducts with leaf-like stromal projections in the lumen. A portion of the stroma was very cellular with at ypia and a high mitotic rate. In addition, there was a small focus with wel l differentiated rhabdomyoblasts. This case is the second description of a cystosarcoma phyllodes of the prostate with rhabdomyoblasts differentiation . With radical surgery and chemotherapy only partial remission could be obt ained.