Primary primitive neuroectodermal tumor of the urinary bladder: a case report and literature review.

Primitive neuroectodermal tumor (PNET) arising in the urinary bladder is extremely rare. Here, we report a case of primary PNET of the urinary bladder in an aged Asian man that showed an aggressive clinical course. A 74-year-old man presented with frequency, dysuria, and gross hematuria. Pelvic computed tomography showed a mass in the urinary bladder. Microscopically, the tumor revealed sheets of uniform, small, round, blue cells, and immunohistochemical examination demonstrated primary PNET of the urinary bladder. Palliative chemotherapy was administered. After three courses of chemotherapy, his disease progressed and he died 4 months after diagnosis.