A Case of Medullary Carcinoma with Lymphoid Stroma of the Stomach Showing 2 Tumors Which were Connected with Intraepithelial Spread

Abstract

A 60-year-old man medicated for a gastric ulcer and admitted due to an abnormality seen in gastroendoscopic examination was found in endoscopic and radiographic examination of the stomach to have 2 elevated adjacent lesions, on the lesser curvature of the gastric body. The proximal lesion was covered partially with normal epithelium having a linear depression in the center with gradual marginal elevation. The distal lesion had a deep circular depression in the center of the lesion with round marginal elevation resembling a small Borrmann type 2 tumor. The epithelium between the 2 lesions, which seemed separate appeared normal under a diagnosis of early gastric cancer, we conducted proximal gastrectomy. Histopathologically, both tumors were poorly differentiated adenocarcinoma, with severe lymphocytic infiltration and lymphoid follicles. The 2 tumors were connected with intraepithelial spread. Epstein-Barr virus encoded RNA (EBER-1) was detected in both tumor cells by in situ hybridization. This suggests that Epstein-Barr virus infection is related to carcinogenesis.