Ileo-Ileal Intussusception Secondary to Neuroendocrine Tumor in Adult Patient

BACKGROUND Intussusception occurs when a proximal region of the intestine telescopes into a distal region. It is more common in the pediatric population, with only 5% of cases occurring in adults. The most frequent causes of adult intussusception are malignancy, polyps, or diverticula. A very rare cause is neuroendocrine tumor (NET). NETs are a diverse group of neoplasms that arise from endocrine cells throughout the body. Here, we present a case of a patient who presented with ileo-ileal intussusception due to a T3N1 NET, grade 1. CASE REPORT A 60-year-old man with a medical history of peptic ulcer disease presented for evaluation of lower abdominal pain, dark "maroon" colored stools, and hematemesis for the past 2 days. Computed tomography (CT) of the abdomen and pelvis showed ileo-ileal intussusception. Exploratory laparotomy revealed a small bowel mass approximately 30 cm from the ileocecal valve. After removal of 15 cm of small bowel and 13 lymph nodes, pathology confirmed the diagnosis of a T3N1 NET, grade 1. He was subsequently referred to the Oncology Department, where he was cleared, with no need for additional surveillance. CONCLUSIONS In adult patients presenting with nonspecific abdominal pain and concern for small bowel obstruction, a CT scan can be helpful in diagnosing intussusception. When dealing with adult intussusception, the etiology needs to be carefully investigated to search for an underlying malignancy. In rare occasions, small bowel NETs can be the cause of intussusception and can therefore be identified early, before they metastasize and present with carcinoid syndrome.