Abstract

We reviewed a total of 36 cases of gastrointestinal carcinoid tumors during a period of ten and a half years at Seoul National University Hospital, looking at their histologic and ultrastructural features, as well as immunohistochemical results, then we correlated these with location. The primary sites of carcinoid tumors were rectum(39%), stomach(25%), appendix(22%), small intestine(8%) and colon(6%), in order of frequency. The predominant histologic types by organ were mixed and solid(A) types in all location, the solid type(type A) in the stomach, and tubular type(type C) in the rectum. Six out of 8 cases of appendiceal carcinoid were type A and the other two cases were mucinous carcinoid. Tubular adenoma or adenocarcinoma was associated with 36% of the rectal carcinoids, with one case of carcinoid in the small intestine, and one(11%) of the gastric carcinoids was found near an adenocarcinoma. Metastasis was found in one case of ileal carcinoid(100%), one case of cecal carcinoid, 3 of gastric carcinoid(33%) and 2 of rectal carcinoid(14%). Primary tumor size ranged from 1 to 7 cm. Tumor necrosis and endolymphatic tumor emboli were found in 57% and 43% of the metastatic carcinoids, respectively. PCNA index showed a borderline significant difference between metastatic and nonmetastatic groups(P value=0.063). The low prevalence of appendiceal carcinoid and the relatively high prevalence of gastric-rectal carcinoid may reflect a low chance of incidental appendectomy and frequent detection of gastrointestinal endoscopy.

• Keywords: Gastrointestinal tract;Carcinoid;Pathology;