S2806 A Case of Ileocecal and Distal Sigmoid Carcinoid Tumor With Liver Metastasis

Abstract

INTRODUCTION: Carcinoid tumors are rare, slow-growing neuroendocrine tumors (NET), often asymptomatic and may not become apparent until there is evidence of metastatic disease or carcinoid syndrome. Digestive involvement is most common in the appendix, mesentery and the ileum. We present a case of carcinoid tumor in the ileocecal valve and distal sigmoid colon, complicated by liver metastasis. CASE DESCRIPTION/METHODS: A 55 year-old African-American with no significant past medical history, presents for eight months of progressive weight loss, subjective fever, chronic watery diarrhea and episodes of flushing. Physical exam was significant for thin habitus. Laboratory tests revealed macrocytic anemia and progressive increase in transaminases (ALT 224 U/L, AST 217 U/L). Right upper quadrant US was showed scattered small indeterminate liver lesions of 1.5 cm. CT abdomen/pelvis revealed a 2.3 × 2.1 cm focal mass and thickening of the terminal ileum and a 2.1 cm mass in the distal sigmoid colon, in addition to multiple liver lesions. Percutaneous liver biopsy consistent with two minute clusters of NET cells at 0.15 mm and 0.10 mm showed positive immunohistochemistry (IHC) positive for synaptophysin an chromogranin. Further laboratory investigation included elevated urine 5-HIAA (60 mg/24 h) and elevated levels of serum chromogranin (167 ng/mL). Colonoscopy with terminal ileum intubation showed a 7 mm pedunculated broad based polyp in the sigmoid colon and a protruding polypoid irregular ileocecal valve. Histopathology from colonic mucosa showed non-specific chronic inflammation and immunoreactivity for CD45, which supports the diagnosis of NET. The patient was treated with Sandostatin injections monthly with significant clinical improvement, and is followed by Oncology and Gastroenterology services. DISCUSSION: Carcinoid tumors although rare, can be found throughout the gastrointestinal tract, generally in the appendix or ileum. Our patient presented with clinical and immunohistochemical characteristics consistent with carcinoid tumor, and apparent unusual localization in the ileocecal valve and distal sigmoid colon. Associated liver metastasis was evident. Recent literature reports that the overall incidence of carcinoid tumors has been steadily increasing likely due to advances in testing, however most cases are being detected after wide-spread disease.CONCLUSION. Further description of the biological and histopathological characteristics of carcinoid tumors is needed for implementation of early detection techniques.