Retroperitoneal Schwannoma in the Renal Hilum: A Case Report.

A 73-year-old male was referred to our department for further treatment of a right retroperitoneal tumor. Contrast CT showed a tumor mass measuring 33 × 26 mm in size with poor contrast enhancement. Because we were unable to rule out tumor malignancy, we planned an operation. The tumor was easily separated and removed without nephrectomy. Histological study revealed a schwannoma. It is rare for this kind of tumor to arise from the retroperitoneum (approximately 0.7% of all cases), in particular at the renal hilum. We herein report a rare case of retroperitoneal schwannoma arising from the renal hilum.