[A case of retroperitoneal schwannoma: diagnostic usefulness of magnetic resonance imaging].

A 36-year-old man visited our hospital with a chief complaint of difficult urination. He was admitted for further examination because ultrasonography showed a heterogeneous solid mass in the lower abdomen. Intravenous urography showed the right ureter and bladder to be pushed leftward without hydronephrosis. Computerized tomography showed a giant solid mass in the retrovesical space. Magnetic resonance imaging revealed a round, well-encapsulated tumor, showing low intensity on the T1-weighted image, heterogeneously high intensity on the T2-weighted image and irregular enhancement with Gd-DTPA. Histopathology of the extirpated tumor was benign schwannoma.