[Seminal vesicle cyst associated with ipsilateral renal dysplasia and vena cava malformation : a case report].

We report a rare case of seminal vesicle cyst associated with ipsilateral renal dysplasia and vena cava malformation. A 76-year-old man was hospitalized because of difficulty in urination. We diagnosed benign prostate hyperplasia with vesical diverticulum and administered medication that was found to improve urination. However, positron emission tomography-computed tomography showed a large mass in the pelvic region ; therefore, additional examinations were performed. Urethrocystography showed a filling defect in the bladder. Computed tomography revealed the absence of the right kidney and the presence of a double vena cava and a large seminal vesicle cyst on the same side. Magnetic resonance imaging showed a cystic ectopic ureter associated with the seminal vesicle cyst. Therefore, we diagnosed the patient with a seminal vesicle cyst associated with ipsilateral renal dysplasia and performed cyst puncture. The patient is currently free from urinary symptoms at 12 months after surgery.