[Anterior urethral diverticular stones and retrocaval ureter in male: a case report and review of literature in Japan].

A case of diverticular stones in the male anterior urethra with retrocaval ureter is reported. A 26-year-old man visited our hospital for examination, who had experienced spontaneous stone discharge a few days earlier. Computed tomographic (CT) scan with ureteral catheterization and urethrography revealed a retrocaval ureter and urethral diverticular stones. Resection of urethral diverticulum with 7 stones and right ureteroplasty were performed. The urethrography and drip infusion pyelography (DIP) 9 months after operation showed no abnormal findings. The largest stone was 28 x 22 x 20 mm in size and 20 g in weight. The main components were ammonium dihydrogen-urate (70%), carbonate apatite and struvite. Histological feature of the epithelium of the urethral diverticulum indicated normal skin with hairs. Pathological diagnosis was para-urethral dermoid cyst. Our case is the 67th case of the male urethral diverticular stones and the first case of those with retrocaval ureter in Japan.