A Case of Small Intestinal Neuroendocrine Tumor Operated on Urgently due to Strangulated Bowel Obstruction

Abstract

An 80-year-old man visited his previous physician 3 years earlier with a complaint of abdominal pain, and contrast-enhanced computed tomography (CT) showed enlarged upper mesenteric lymph nodes. Upper and lower endoscopies and capsule endoscopy showed no abnormal findings, and the patient was followed. The patient presented to our emergency department with abdominal pain, and contrast-enhanced CT showed narrowing of the ileum and a weakening of the contrast effect of the bowel wall, but no obvious paraneoplastic lesions were noted. A diagnosis of strangulated bowel obstruction was made, and emergency surgery was performed. The abdominal cavity was opened, and an enlarged lymph node of about 3 cm in the mesentery of the small intestine was found adhering to the surrounding mesenteric tissue from around the ileocolonic arteriovenous root and infiltrating toward the superior mesenteric artery. The mesentery and small intestine were distorted, starting from the enlarged lymph node. The torsion was released, but the small intestine was necrotic, and resection of the small intestine and right hemicolectomy was performed. Histopathological examination showed a small intestinal neuroendocrine tumor (NET) G2 with peritoneal dissemination. The patient underwent re-operation due to postoperative suture failure, and is doing well after the re-operation. NETs of the small intestine are relatively rare in Japan, and ileal NETs are reported to account for 0.6% of gastrointestinal tract NETs. The present case of a small intestinal NET with strangulated bowel obstruction is rare, and it is reported along with a review of the literature.