Abstract
A 34-year-old man was referred to the hospital for an abdominal tumor, which was detected at another hospital when he visited there because of abdominal pain and diarrhea, on February 1, 2000. A retroperitoneal tumor in the pelvis was revealed by abdominal ultrasonography, CT, magnetic resonance imaging, and angiography. The patient underwent a surgical operation on March 28. The huge tumor was found to fill the almost entire pelvic cavity. It was removed by a transabdominal method. The extirpated tumor was 12×15×9cm in size, 1100g in weight and elastic soft. It had a yellowish white appearance and was well encapsulated on a cut section. It was histologically composed of spindle cells which were arranged in short bundles or interlacing fascicles. The tumor cells showed slight nuclear atypsim but no mitosis. Immunohistochemically, the tumor cells showed a positive stain for S-100 protein, Vimentin, and NSE. The definite diagnosis was benign schwannoma of Antoni type A and B. The postoperative course was uneventful. The patient was discharged from the hospital on 14th hospital day. There have been no signs of recurrence as of 18 months after the operation.
