[A case of giant bladder stone in a young man with neither lower urinary tract dysfunction nor foreign body in the bladder].

A 38-year-old man visited our hospital complaining of lower urinary tract symptoms. He had undergone extracorporeal shockwave lithotripsy to remove a right renal stone two times when he was 24 years old. Since examinations revealed right staghorn calculi and a giant bladder stone, vesicolithotomy was carried out. The removed stone measured 95 × 75 × 55 mm and weighed 250 g. We hypothesized that a fragment of the upper urinary tract stone had reached the bladder which could not be discharged spontaneously, and grew in the bladder. After the operation, uroflowmetry and voiding cystourethrography were performed and the results indicated no abnormalities in the lower urinary tract function.