A case of urachal cyst prolapsed from external orifice. Review of the literature of 172 cases in Japan

: A case of urachal cyst prolapsed from external orifice in a 15-year-old female is reported. She was admitted to the hospital with complaints of macrohematuria and palpation of a thumb's head size tumor prolapsed from external urethral orifice. An urachal cyst was suspected from the cystogram, CT and the cystoscopy. We extirpated the tumor with the bladder wall. Pathological examination demonstrated a urachal cyst.