S2830 Hematochezia of Unknown Origin

Abstract

INTRODUCTION: The estimated incidence of neuroendocrine tumors in the United States ranges from 2.5 to 5 cases per 100,000. Although relatively rare, the most common location for them is the small bowel, specifically the ileum. Rarely do they present with hemodynamically significant bleeding or at a young age. The following case is a rare presentation of substantial hematochezia from a small bowel neuroendocrine tumor in a young, otherwise healthy male. CASE DESCRIPTION/METHODS: The patient is a 26 year old male who presented to hospital complaining of bloody stools.His hemoglobin on admission was 6.9 dg/L. Patient underwent a CTA that was read as 1.6 cm mesenteric mass and right colon extravasation, but subsequent angiography was negative for active bleeding. A follow-up Meckel’s scan was also negative. Within 3 days, the patient had 12 bloody stools and required transfusion of 6 units of blood. An EGD and colonoscopy revealed no sources of acute bleed. Decision was then made to transfer the patient to a higher acuity facility for push enteroscopy and video capsule endoscopy. VCE on transfer was remarkable for 3 areas of fresh blood mixed with mucosa in the distal small bowel. Decision was made for a push enteroscopy the next day, however it revealed a normal small bowel from the ileocecal valve to about 100cm into the ileum. The patient was stabilized and a few weeks later underwent an exploratory laparotomy where a mesenteric mass and 2 lymph nodes were biopsied. There was also appreciable denseness to the mid and distal jejunum. Subsequent biopsies were remarkable for a well-differentiated, G2 neuroendocrine tumor likely representing a metastatic tumor from the adjacent small intestine. Since surgery, the patient reports no further episodes of hematochezia. DISCUSSION: The most common site of small bowel neuroendocrine tumors is the ileum, approximately 60-100cm from the ileocecal valve. While abdominal pain is the most common presentation, GI bleeding is the initial symptom in 23-29 percent of cases. One study of neuroendocrine tumors found it took an average of 2.3 tests before a diagnosis was determined. In this case, the patient underwent multiple imaging and endoscopic evaluation before ascertaining a cause for his bleeding. These tumors are typically found in the 6th or 7th decade of life, which is one of the unusual facets of this case. For a tumor of this size, surgery with extensive lymph node resection is associated with low local recurrence.Figure 1.: Mesenteric tumor pathology report.