Duodenal Gastrointestinal Stromal Tumor Treated by Wedge Resection in a Patient with Neurofibromatosis Type 1: Report of a Case and Review of the Japanese Literature.

A case of duodenal gastrointestinal stromal tumor (GIST) treated by wedge resection in a patient with neurofibromatosis type 1 (NF-1) is reported. A 55-year-old man with a history of NF-1 was admitted for surgery for a duodenal tumor. Upper gastrointestinal endoscopy revealed a 2.5 cm duodenal submucosal tumor. Abdominal computed tomography showed a homogenously enhanced mass in the third portion of the duodenum. The patient successfully underwent wedge resection of the duodenal tumor. Histological examination revealed proliferation of spindle tumor cells arranged in a bundle pattern. This tumor was immunohistochemically positive for c-Kit and CD34, and negative for S-100 and α-SMA. A mitotic count showed 3 mitoses per 50 high-power fields. The tumor was diagnosed as a low-risk GIST. The patient's postoperative course was uneventful. GIST in a patient with NF-1 is rare, only 27 cases being reported in the Japanese literature.