A Case of Retroperitoneal Schwannoma (20 cm) Accompanied by Vertebral Scalloping

Abstract

It is not unusual to encounter a retroperitoneal tumor, but it is comparatively rare to find a tumor so large that it is accompanied by vertebral scalloping. We experienced such a case in which a one-stage resection was performed by a 4 divisions-joint surgery. The patient was a woman in her sixties. She was transported by ambulance to hospital due to abdominal pain and vomiting, and was diagnosed with acute pancreatitis. Computed tomography (CT) revealed a large retroperitoneal tumor. After remission of pancreatitis, we performed a retroperitoneal tumor resection. On the day prior to the surgery, we embolized the feeding vessels with coils by interventional radiology, and on the day of the surgery, we inserted a right ureteral stent before the surgery commenced. At first, we detached the tumor that had invaded the vertebral body with the patient in the dorsal position. Then, with the patient in the supine position, by ligating the perforating branches from the inferior vena cava we incised the anterior longitudinal ligament of vertebra, and removed the tumor without membrane damage. The specimen was a sandglass-type tumor over 20 cm in size and weighing 1,756 gm. The pathological examination revealed the spindle-type, disordered cell proliferation, positive S-100 protein staining, and a MIB-1 index of less than 1%. Therefore, the tumor was diagnosed as a benign schwannoma. Three years after surgery, the patient was free from numbness, and alive without recurrence. Although a giant schwannoma accompanied by vertebral scalloping is rare, we successfully resected it using one-stage surgery. Thus, we report the case with a review of the literature.