Minute carcinoid tumor of the stomach: report of two cases and review of the Japanese literature.

Two cases of minute carcinoid tumor of the stomach were reported and 167 cases of gastric carcinoid in Japan up to December 1984 were reviewed. In Case 1, two carcinoid tumors of the body were found as sessile polyps of 4.2 and 4.8 mm in diameter, respectively, the latter having been detected two years previously. Case 2 had 60 polypoid lesions on the body and the fundus, ranging from 1.0 to 4.5 mm in diameter. In both cases the tumor invasion was limited to the mucosa and submucosa, although many micronests were found around the polypoid lesions. Among 167 cases of gastric carcinoid in Japan, 12 were 5 mm or less in size and 12 were 6 to 10 mm in size. In the former cases, there was no metastasis while in the latter, metastasis to the lymph nodes was found in 25.0%. We propose that the minute gastric carcinoid should be defined as a tumor not exceeding 5 mm in size with the invasion limited to the mucosa or submucosa. In addition, we emphasized that radical gastrectomy should be performed even for the minute carcinoid tumor because of its multicentricity and invasiveness.