Abstract
A man in his late 70s was diagnosed as having gastric carcinoma following a medical checkup. Based on preoperative upper gastrointestinal endoscopy, the patient was diagnosed as having multiple, well-differentiated, early gastric carcinomas at three sites (two sites in the upper part of the body of stomach and one in the gastric pylorus), and total gastrectomy was performed. Histopathological analysis showed multiple early gastric carcinomas at a total of five sites, including two lesions that had not been diagnosed preoperatively. All lesions were well-differentiated mucosal carcinomas, had no metastases, and were staged as fT1N0H0P0CY0M0 fStage Ia. In addition, Schistosoma japonicum eggs were found dispersed from the submucosa to the subserosa, and the number of eggs tended to be greater around the carcinomas. Although few changes indicating atrophy or intestinal metaplasia were seen in the background gastric mucosa, immunostaining showed that the tumors had an intestinal-type mucosa. The patient has been healthy for three years postoperatively without signs of recurrence. Synchronous multiple mucosal gastric carcinomas in which all lesions are well-differentiated are extremely rare. The present case was not associated with intestinal metaplasia and may have been a case of multiple early intestinal-type gastric carcinomas caused by the presence of S. japonicum eggs. We report the present case with reference to the literature because it was a rare case, and also because it was considered valuable from the perspective of elucidating the mechanism of gastric carcinogenesis.
