Ultrasound diagnosis of a prostatic cyst causing acute urinary retention.

A 31-year-old man was referred to our genitourinary department in acute urinary retention. One week previously he had had a similar episode relieved by bladder catheterization. For 1 month prior to that he had been having frequency of micturition, postmicturition dribbling, and a feeling of incomplete bladder emptying. He had some dysuria and nocturia. His past medical history was otherwise unremarkable. On examination, he had suprapubic dullness due to a distended bladder. Remainder of physical examination, including rectal examination, was nonnal. Pelvic ultrasound and i.v. urography were perfonned prior to catheterization. Real-time ultrasound, using a 3.5-MHz transducer, showed a 2-cm cyst in the bladder, closely related to the prostate and lying slightly to the left of the bladder neck (Fig. 1). This did not change during the examination. The urogram was nonnal. Following catheterization, urine examination was nonnal, including microscopy and culture. Repeat ultrasound showed no change in the cyst.