We have previously demonstrated that gastric and intestinal endocrine cell (End-cell) marker expression is important for assessment of the histogenesis of endocrine cell tumors. However, the End-cell phenotypes of carcinoid tumors in the rectum remain largely unclear. We therefore examined marker expression of rectal carcinoid tumors. We evaluated 20 rectal carcinoid tumors (as well as 8 from the stomach for comparison) phenotypically, using gastrin, gastric inhibitory polypeptide (GIP) and glucagons-like peptide-1 (GLP-1) as End-cell markers. Rectal carcinoid tumors were divided into 3 endocrine-gastric (e-G), 16 endocrine-gastric-and-intestinal mixed (e-GI), 1 endocrine-intestinal (e-I), and 0 endocrine-null (e-N) types, thus 19 (e-G+ e-GI types, 95%) had gastric phenotypic expression, while 17 (e-GI+ e-I types, 85%) harbored intestinal elements. Stomach carcinoid tumors were classified as 6 e-G and 2 e-N types, respectively. In conclusion, most rectal carcinoid tumors exhibited the e-GI type, suggesting the importance of gastric End-cell marker expression for histogenesis of the rectal carcinoid tumors. Further studies of pathological and biological analyses are needed to clarify the histogenesis of the carcinoid tumors.
All Science Journal Classification (ASJC) codes
- Cancer Research