Laparoscopic Resection for an Extragastrointestinal Stromal Tumor of the Retroperitoneum—A Case Report—

Abstract

A 37-year-old woman was diagnosed with a retroperitoneal tumor at the dorsal side of the stomach and pancreas measuring 85 mm in diameter, which was 38 mm in diameter 3 years previously. We performed laparoscopic resection, which revealed that the tumor was located in the anterior pararenal extraperitoneal space at the dorsal aspect of the omental bursa. There was no continuity between the tumor and stomach, pancreas, and left adrenal gland. Histologically, the tumor consisted of spindle cells arranged in short fascicles. Immunohistochemical analysis revealed positive staining for c-kit and DOG-1. Mitotic figures were observed in 2/50 high-power fields. Based on these findings, the final pathologic diagnosis was of a high-risk extragastrointestinal stromal tumor (EGIST) of the retroperitoneum. Following the surgery, the patient has been taking imatinib mesylate and has remained alive without recurrence for 12 months. Since most EGISTs develop in the mesentery or omentum, EGISTs located in the retroperitoneum are more uncommon. We present this rare case of EGIST of the retroperitoneum that was laparoscopically resected.