BENIGN SCHWANNOMA SURROUNDING AND OBSTRUCTING THE URETEROPELVIC JUNCTION - FIRST CASE-REPORT

With a varied presentation and a difficult preoperative diagnosis, sch wannoma accounts for only a small percentage of retroperitoneal tumors . Moreover, malignant schwannoma of the adrenal gland, kidney and rena l pelvis has previously been described. We report the first case of be nign schwannoma causing obstruction by external compression of the ure teropelvic junction. A case report of a male patient who complained of a 3-month history of dull lumbar pain on the right side is reported. Using intravenous pyelogram, sonography and computed tomography a beni gn tumor of the retroperitoneum was suspected. Upon exploration, the s uspected diagnosis of the tumor's retroperitoneal origin was confirmed . After the histological and immunohistochemical studies the diagnosis was verified. The diagnosis, treatment and histological features of b enign schwannoma are discussed. A brief review of the literature is al so included.