Presentation of CaseA 36-year-old man was admitted to the hospital because of urinary retention.He was well until one year earlier, when he became impotent. Three months before admission intermittent difficulty in voiding developed, with hesitancy, decreased force of stream, incomplete voiding, urinary frequency, and nocturia, and he became constipated. Two months before admission he began to have pain in the left flank that usually occurred on bending forward and was relieved by sitting. Two days before entry dysuria recurred, and on the next day he was unable to void or to move his bowels. He was taken to . . .