S3448 An Unusual Presentation of a Rare Pathology

Abstract

INTRODUCTION: Although gastrointestinal stromal tumors (GISTs) are known to be the most common mesenchymal tumors of the GI tract, they account solely for approximately 1 percent of primary gastrointestinal cancers. GIST incidence is about 0.68 per 100,000 and they are found most commonly in middle aged and older patients. Most of these tumors are diagnosed incidentally via endoscopy, surgery, or imaging. This case report highlights an unusual presentation of an uncommon tumor. CASE DESCRIPTION/METHODS: A 66-year-old male patient with past medical history of hypertension, obesity, diabetes mellitus type II, and obesity hypoventilation syndrome presented to the emergency department due to a 1-week history of dark tarry stools. The patient reported about three episodes daily. Associated symptoms included palpitations and pressure-like, mid- sternal, intermittent chest pain without radiation. The patient denied use of aspirin, nonsteroidal anti-inflammatory drugs or anticoagulation. In 2015, he underwent an upper endoscopy due to melena and dyspepsia which showed evidence of non-erosive gastritis and duodenitis with a biopsy positive for H. pylori infection. Although he received treatment, there was no evidence of eradication. Two years later he had a colonoscopy without major findings. Initial labs upon arrival showed a Hgb of 7.6 g/dL (baseline value:15g/dL). BUN was not elevated and BUN/Cr was 15.3mg/dL. Rectal exam was negative for bleeding. He was started on a high dose proton pump inhibitor, placed NPO, and transfused two PRBCs. Initial upper endoscopy showed erosive gastropathy, duodenitis, and an inlet patch. The patient rebled 3 days after the procedure. A second look upper endoscopy showed evidence of blood beyond the second portion of the duodenum, reason for which the scope was changed to pediatric colonoscopy scope for further evaluation. A large subepithelial lesion was found at the third portion of the duodenum (Figure 1). The superior aspect of the lesion was ulcerated and oozing. Appearance was suggestive of a GIST. Pathology report confirmed the diagnosis of a gastrointestinal stromal tumor, spindle cell type C-KIT positive (Figure 2). DISCUSSION: This case is particularly relevant today as cases of GIST continue to increase given the availability of new diagnostic criteria. Although most GISTs are found incidentally, this uncommon entity should be included in the differential diagnosis of gastrointestinal bleeding when no other etiology is found.Figure 1Figure 2