Gastric carcinoids: a statistical evaluation of 1,094 cases collected from the literature.

Gastric carcinoids are a rare gut endocrinoma, and only a few series dealing with limited aspects have been published. This study evaluates the present status and characteristics of gastric carcinoids in a statistically reliable series of 1,094 cases that were carefully evaluated, computerized, and analyzed by the "Gut-Pancreatic Endocrinoma Analyzing System." Routine statistical analysis was carried out on 1,011 patients, excluding 83 with atypical carcinoids, focusing on clinical manifestations, location, depth, and size of the lesions in relation to metastases, immunohistochemistry, carcinoid syndrome, serotonin activity, electron microscopy, multicarcinoid complex with type A gastritis, and postoperative outcome. A tumor size of 20 mm or less comprised 60.8% of the series, with a metastasis rate of 15.1%, and depth of invasion to the submucosa occupied 53.8%, with a metastasis rate of 13.2%. Carcinoid syndrome was encountered in 4.0% of the patients. Elevated serotonin activity was detected in 22.3% overall and in 67.7% of the patients with carcinoid syndrome (P < 0.01). Multicarcinoid complex with type A gastritis was detected in 140 of 347 patients with multicarcinoid complex, and 97.1% had associated lesions in the nonantral regions of the stomach. A comparative evaluation between patients with and without type A gastritis indicated a number of significant differences including male to female ratio, age distribution, location, tumor size, depth of invasion, metastasis, and prognosis.