S6055 When Retention Reveals More: A Neuroendocrine Tumor Diagnosed Following Capsule Endoscopy

Introduction: Video capsule endoscopy (VCE) is a widely utilized, non-invasive modality for evaluating the small bowel, particularly in cases of small bowel bleeding. While generally considered safe, one of its most concerning complications is capsule retention, with an estimated incidence of approximately 2%. Though uncommon, small-bowel tumors may underlie such retention events. These neoplasms account for only 0.6% of all new cancer diagnoses in the United States and represent about 3% of all gastrointestinal malignancies. Herein, we describe a case in which capsule retention led to the diagnosis of a previously undetected small intestinal neuroendocrine tumor (SI-NET), emphasizing the importance of early recognition of retention events. Case Description/Methods: A 73-year-old man with end-stage renal disease on hemodialysis presented with a 15-day history of intermittent melena. He was hemodynamically stable, denied abdominal pain or prior surgical history, and laboratory evaluation revealed microcytic anemia. Esophagogastroduodenoscopy demonstrated moderate gastritis and duodenitis with non-diagnostic biopsies, while colonoscopy revealed multiple small polyps without significant findings. Due to ongoing bleeding, VCE was performed and revealed granular, nodular, and congested mucosa in the proximal small bowel. The capsule did not reach the cecum after 11 hours and 23 minutes. Computed tomography abdomen confirmed capsule retention in the distal ileum without signs of obstruction. Upper device-assisted enteroscopy showed mild duodenal inflammation and normal jejunal mucosa up to 390 cm beyond the pylorus. Lower device-assisted enteroscopy reached 100 cm proximal to the terminal ileum, with a tattoo placed near the point of maximal insertion. An exploratory laparotomy was performed for persistent capsule retention, revealing tattooed areas and a freely mobile capsule located just proximal to an intestinal stricture. Small bowel resection was completed, and pathology revealed a well-differentiated ileal neuroendocrine tumor (WHO Grade 1) positive for chromogranin, synaptophysin, and CAM5.2, with Ki-67 <1% and no lymphovascular invasion. The patient was referred to oncology for ongoing evaluation. Discussion: This case highlights the importance of early recognition of capsule retention during the evaluation of obscure gastrointestinal bleeding. Although rare, capsule retention should prompt investigation for underlying pathology, as it may reveal significant findings such as small bowel tumors.