[A clinicopathological study of signet-ring cell carcinomas of the stomach].

Surgically resected signet-ring cell carcinomas of the stomach have been clinicopathologically investigated. Although this type of carcinoma was found to be widely spread in the propria mucosa, a deeper invasion beyond the submucosa appeared more slowly than in other types of carcinomas. For example, the larger the early carcinoma in which the invasion was restricted to within the submucosa, the greater the incidence of a signet-ring cell carcinoma increase, especially in cases involving the mucosa. The incidence of a nodal metastasis was found to be lower than in cases of a moderately and poorly-differentiated adenocarcinoma in the early stage. However, when the signet-ring cell carcinomas invaded beyond the submucosa, the tumor cells spread rapidly and widely in the wall with a subsequent abdominal implantation, causing ascites and peritonitis carcinomatosa. It seemed likely that this deep invasion was accelerated by cellular change, such as the enlargement of nucleus, cellular atypy, and a decreased mucin production. As signet-ring cell carcinoma arise from the neck of glands and infiltrate the propria mucosae under the superficial epithelium, diagnosis by the barium enema and an endoscopic examination is very difficult in the case of small-size lesions. In lesions greater than 1 cm in diameter, these carcinomas usually showed an erosive and/or ulcerated appearance.