Preoperative diagnosis of mucinous gastric adenocarcinoma by endoscopic ultrasonography

The aims of this study were to investigate the characteristic features of mucinous gastric carcinoma on endoscopic ultrasonography (EUS) and to demonstrate the usefulness of EUS in the preoperative diagnosis of this disease.

Twelve patients with mucinous gastric carcinoma who underwent EUS examination between April 1984 and April 1995 were enrolled in this study. All patients subsequently underwent surgery. Histopathologically, tumors were classified according to the mucin content (high or moderate) and the glandular formation of the tumor cells (well or poorly differentiated). Finally, the histological and endosonographic features were compared.

In all patients, the infiltrated wall appeared echogenic because of diffusely distributed, reticular, highly echoic speckles in the submucosa and muscularis propria. The presence of mucinous lakes surrounded by reactive fibrous tissue correlated well with reticular, highly echoic speckles on EUS. There was an increase in echogenicity and thickness of the muscularis propria, depending on the invasion of the mucin. Although the boundary between submucosa and muscularis propria was distinct and the five-layered gastric wall structure was generally preserved, the mucosal layer was not discriminated in patients with poorly differentiated mucinous carcinoma with high mucin content.

As a preoperative diagnostic procedure, EUS may be useful in recognizing the mucinous component of gastric tumors and may facilitate the differentiation of mucinous carcinoma from other gastric epithelial tumors.