Management of Multicentric Small Bowel Carcinoids: Use of Capsule and Intraoperative Endoscopy

Abstract

Purpose: Carcinoid tumors are rare neuroendocrine tumors most commonly found in the gastrointestinal tract, namely the ileojejunum and appendix. Up to 30% of cases of small bowel carcinoids are multicentric. We present two cases that illustrate the utility of video capsule endoscopy (VCE) in the localization of multicentric carcinoids not detected by somatostatin receptor scintigraphy. Case 1: A 57 year old female was referred for obscure occult gastrointestinal bleeding and intermittent abdominal pain. Upper endoscopy and colonoscopy were unremarkable. VCE revealed multiple umbilicated polyps, ranging from 3 mm to 1.5 cm, throughout the mid to distal small bowel. Retrograde double balloon enteroscopy (DBE) was performed with polypectomy of the distal most polyp 45 cm proximal to the IC valve. Pathology revealed well-differentiated neuroendocrine tumor. Indium-111 pentetreotide scintigraphy did not show any specific uptake. Serum chromogranin A (CGA) and 24-hr urine 5-HIAA level were normal. To aid with surgical resection, intraoperative enteroscopy was performed to locate the position of the most proximal tumor, enabling primary resection of 70 cm of involved small bowel. Pathology confirmed fifty-seven (57) metastatic carcinoid tumors along the resected segment. Case 2: A 56 year old female with no prior medical history presented with acute abdominal pain, with associated vomiting and obstipation. Abdominal CT scan showed small bowel obstruction with a transition point in the distal ileum. Exploratory laparotomy revealed two areas of stricture secondary to mass effect. Primary resection of the affected small bowel was performed. Pathology showed a total of eleven carcinoid tumors without mesenteric spread. Biochemical markers (CGA and 5-HIAA) were normal. Although octreotide scan did not show any residual foci, VCE revealed a 1-cm polypoid mass in the terminal ileum. Colonoscopy with biopsy was performed with histopathology confirming carcinoid tumor. Conclusion: Carcinoids comprise about one-third of small intestinal tumors, and often are multicentric. Symptoms may be nonspecific, ranging from abdominal pain to bowel obstruction. Surgery is the cornerstone of therapy for small bowel carcinoids, with the extent of resection dependent on tumor size and location. Therefore, accurate localization of the primary tumors is essential to management. Somatostatin receptor scintigraphy has a high sensitivity for primary and metastatic disease, although the yield for multicentric tumors has not been specifically studied. These cases illustrate the utility of pre- or postoperative VCE along with intraoperative enteroscopy in the detection and localization of multicentric small bowel carcinoid tumors.