[A case of unilateral giant hydronephrosis with contralateral dwarf kidney].

A 54-year-old woman was admitted to our hospital for oliguria and left lower abdominal pain. She had renal dysfunction with a serum creatinine of 9.1 mg/dl and blood urea nitrogen of 96.5 mg/dl. Plain computed tomography and magnetic resonance imaging revealed right dwarf kidney and left giant hydronephrosis with extravasation of urine. MR-urography revealed left dilated ureter caused by ureterovesical junction (UVJ) stenosis. Therefore, percutaneous nephrostomy was immediately performed to treat postrenal failure, with resulting collection of approximately 1,650 ml of urine. Subsequently, left ureterocystoneostomy was performed for the treatment of UVJ stenosis because improvement of left UVJ stenosis had not been confirmed by nephrostography during follow-up. Judging from the past history of myoma operated and reactive fibrosis of stump of left ureter histopathologically, it was considered that acquired UVJ stenosis had led to giant hydronephrosis.