[Undifferentiated Prostate Cancer Treated with Radiation Therapy].

We describe a 75-year-old man with undifferentiated prostate cancer that was treated with radiation therapy. He presented at a nearby general hospital with dysuria and pain upon micturition. He was diagnosed with undifferentiated prostate cancer by a needle biopsy and referred to our hospital for further examination and treatment. Enhanced computed tomography and magnetic resonance images showed prostate cancer and right obturator lymph node metastasis measuring 2.5 cm. Cystoscopy and colonoscopy revealed direct invasion of the urinary bladder and rectum. We constructed a vesical fistula and an artificial anus, and then treated the primary tumor and lymph node metastasis with radiation. Undifferentiated prostate cancer is extremely rare and to our knowledge only a few cases have been reported. We suggest that radiation might be effective for treating undifferentiated prostate cancer with or without local invasion and/or metastasis along with total body control.