2612 Gastrointestinal Stromal Tumor Causing Obscure Gastrointestinal Bleeding: An Uncommon Way of Diagnosing an Uncommon Disease

Abstract

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are neoplasms which arise from the tissue of the gastrointestinal tract or, rarely, from other intra-abdominal tissues. CT angiography can be utilized as an alternative imaging study when endoscopic and colonoscopy results are non-diagnostic. We report a case of a 59 year-old-female who presented with recurrent episodes of obscure overt gastrointestinal bleeding and was found to have a GIST. CASE DESCRIPTION/METHODS: A 59-year old woman with history of gastro-esophageal reflux disease presented to the emergency room with bright red blood per rectum and lower abdominal pain for one month. She reported one episode of melenic stool. Physical examination was unremarkable. Laboratory findings revealed a hemoglobin of 9.4 g/dL and a positive fecal occult blood test. Esophagogastroduodenoscopy (EGD) was non-diagnostic. Colonoscopy revealed fresh blood with clots at the terminal ileum, but no evident source of bleeding was identified. As the source of bleeding could not be accurately diagnosed with routine colonoscopy and EGD, an abdominal computed tomography angiography (CTA) was obtained. Abdominal CTA revealed a large exophytic, necrotic mass with hypervascularity to the right of the uterine fundus along with extensive vessels within the bowel wall. The mass, distal portion of the distal jejunum, portion of the terminal ileum were resected. Postoperative pathological examination revealed gastrointestinal stromal tumor (high grade, spindle cell variant). The patient is doing well at a four-month follow-up. DISCUSSION: Patients with GISTs can often be asymptomatic leading to a missed initial diagnosis. When symptomatic, patients often present with bleeding, anemia, mucosal ulceration or mass effect, depending on location. Occasionally they are discovered as incidental findings in radiologic imaging or as incidental findings during surgery or autopsy. Bleeding is the most common presenting symptom and is attributed to the erosion of the gastrointestinal tract lumen with tumor invasion, resulting in hematemesis, melena or anemia. This case offers a unique perspective of GIST diagnosis. In cases where a colonoscopy and EGD along with abdominal series is undiagnostic and capsule endoscopy/balloon enteroscopy are not available - CT angiography can be considered an alternative imaging procedure for the management of GIST tumors. In our case, CT angiography provided exact tumor location preoperatively allowing for appropriate surgical resection.