Conservative Surgical Approach for a Gastrointestinal Stromal Tumor (GIST) of the Third Duodenal Portion: A Case Report from August 2025

Abstract

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms, and their location in the duodenum accounts for less than 5% of cases. We report the case of a 50-year-old male patient with a 7-month history of progressive weight loss and intolerance to solid foods, later extending to liquids, culminating in postprandial vomiting 15 days prior to consultation. Physical examination revealed a constitutional syndrome, and laboratory tests confirmed severe protein-calorie malnutrition. Imaging studies (CT, EGD, MRI) demonstrated a stenotic mass in the third portion of the duodenum, which was impassable to the endoscope. Therefore, a feeding jejunostomy was performed for nutritional optimization prior to definitive surgery. Endoscopic biopsy showed no signs of malignancy. A distal duodenectomy with duodeno-duodenal anastomosis and pancreatic preservation was performed. Histopathological examination confirmed a low-grade GIST (pT2, pN0, R0) with positive immunohistochemistry for CD117 and DOG1. Postoperatively, the patient developed upper gastrointestinal bleeding from the suture line, which was successfully managed endoscopically, followed by a favorable clinical course. This case highlights the importance of considering GIST in the differential diagnosis of duodenal stenosis and demonstrates that complete surgical resection with negative margins is effective, even in anatomically complex locations.