Detection of small-bowel neuroendocrine tumors by video capsule endoscopy

Abstract

Carcinoid tumors are the most common GI neuroendocrine tumors (NET). They often originate in the small intestine. The primary tumor is often difficult to locate, and resection in an early phase is recommended to prevent complications. This study evaluated the value of videocapsule endoscopy (VCE) in the detection of small-intestinal primary carcinoid tumor. Prospective descriptive study. Tertiary referral center. Twenty consecutive patients (13 men, 7 women; 60.5 +/- 9.3 years) with metastatic NET of unknown primary tumor. All patients underwent CT, enteroclysis, nuclear imaging, and VCE of the small bowel. CTs and enteroclysis did not detect a primary small-intestinal carcinoid tumor. Nuclear imaging demonstrated abnormalities in the abdominal area in 13 patients but was unable to relate this to an intestinal localization in any patient. VCE revealed a small-intestinal tumor in 9 patients. Three other patients showed external compression and erosions. At surgery, 5 patients had a small-intestinal carcinoid tumor, and, in 2 patients, a small-intestinal ischemic segment was present. The number of false-positive VCE findings was not clear, because not all patients underwent surgery. The absence of abnormalities at VCE in patients with abnormalities at nuclear imaging might be related to the presence of carcinoid tumor restricted to the mesenterium or to a false-negative VCE. VCE had a high diagnostic yield of 45% for identification of primary small-intestinal carcinoid tumors. Although nuclear imaging had a comparable diagnostic yield, it could not differentiate between intestinal and mesenterial localization of the carcinoid.