NSAID Aids in Diagnosis of Gastrointestinal Stromal Tumor (GIST)

Abstract

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract and may present either asymptomatically or with nonspecific GI symptoms. The subepithelial nature of these tumors and wide range of localization within the GI tract make the diagnosis of GIST difficult. A 53-year-old gentleman, with a history of non-steroidal anti-inflammatory drugs (NSAID) use for chronic pain, presented with lightheadedness. A week prior, he underwent tooth extraction secondary to severe periodontal disease. Patient noted increased NSAID use since surgery. Further, he also reported melanotic stool. Labs showed hemoglobin of 5.8 G/DL. The esophagogastroduodenoscopy found a large 3 cm duodenal ulcer with visible vessel. Biopsies were taken at the ulcer edge and due to the friability of the tissue, bleeding ensued. The brisk bleeding lead to difficulty localizing the site of bleeding, thus a hemo-clip was deployed near the ulcer site as a fiduciary marker. Subsequently, interventional radiology performed celiac / gastric duodenal artery (GDA) and superior mesenteric artery arteriogram with successful GDA embolization and cessation of bleeding. Computerized tomography of the abdomen with contrast, revealed a 5.0 x 5.5 cm mass adjacent to the pancreatic head/peri-ampullary. A duodenal GIST was suspected from biopsies, and the patient subsequently underwent a pylorus-sparing Whipple procedure with biopsies confirming GIST. GISTs occur in 15 per 1 million people. GI bleeds are encountered due to tumor erosion into the mucosal surface of the GI tract. GISTs are localized to the stomach in about 60-70% of cases with localization to the duodenum in only about 3-5% of cases. Due to the subepithelial localization that is typical for these tumors and the nonspecific nature of symptoms, diagnosis can be difficult with metastatic disease encountered upon initial diagnosis in approximately 50% of cases. Surgical resection is the primary treatment of choice for localized GISTs. Our patient's NSAID use led to a GI bleed that unmasked a duodenal ulcer which, subsequently, aided in the diagnosis of a GIST early enough for curative resection.2990_A Figure 1. Endoscopic view of ulcer base within duodenum.2990_B Figure 2. Lateral View CT imaging showing duodenal gastrointestinal stromal tumor (black arrow) and hemoclip (white arrow).2990_C Figure 3. Coronal View CT imaging showing duodenal gastrointestinal stromal tumor (black arrow) and hemoclip (white arrow).