[A case of large diverticular stone of the anterior urethra].

A case of large diverticular stone of anterior urethra is reported. A 70-year-old man was admitted for dysuria, miction pain and hard mass beneath the scrotal skin. Retrograde urethrogram revealed a large stone in anterior urethral diverticulum and extravasation of contrast medium through the fistula from diverticulum. Open resection of diverticulum was performed and the stone was removed. Three months after the operation, the urethrogram showed no abnormal findings. The stone was 40 x 19 x 17 mm in size, weighed 16 g and was mainly composed of calcium phosphate.