Neoplastic changes in the stomach after gastrectomy. Partial gastric resection for benign ulcer disease has been associated with an increased incidence of mucosal dysplasia and invasive adenocarcinoma, particularly 15 to 20 years after resection. These remnant carcinomas are particularly virulent with little hope of resection or cure once symptoms occur. Using a planned protocol of routine endoscopic surveillance with biopsy, the goal was to identify early markers of neoplasia, that is, dysplasia, and a diagnosis of adenocarcinoma of the gastric remnant, while both resection and cure were possible. Between July 1980 and August 1988, yearly flexible gastroscopic examination and random biopsy have been performed on 163 patients at least ten years after gastrectomy for benign ulcer disease. All biopsy results were interpreted for findings of dysplasia and early gastric adenocarcinoma. Results of this ongoing screening program revealed dysplasia of the gastric remnant in nine patients with eventual findings of adenocarcinoma in four of this group. These patients underwent total gastrectomy with findings of limited disease. Five patients with mucosal dysplasia continue to be observed at six month intervals. Three additional gastric carcinomas were found on initial gastroscopic screening, while one patient had adenocarcinoma diagnosed during a third yearly gastroscopic examination. These eight asymptomatic patients with adenocarcinoma in the gastric remnant had a postgastrectomy interval which ranged from 15 to 29 years (mean of 26.5 years). The results of this study support the concept of neoplastic change in the gastric remnant as a function of time from initial gastric resection. Findings of dysplasia on random biopsy indicate a greater likelihood of development of carcinoma of the gastric remnant and identify a subset of patients requiring aggressive endoscopic surveillance. 