Decreased E-cadherin expression permits dissociation and widespread dissemination of gastric adenocarcinoma cells. We studied the relationship between paranuclear E-cadherin distribution and the histopathologic characteristics of gastric adenocarcinomas. E-cadherin immunostains of 173 gastric adenocarcinoma sections revealed paranuclear; punctate to vesicular staining in 18% (16/87) of the intestinal-type adenocarcinomas, 30% (17/56) of the diffuse-type adenocarcinomas, and 30% (9/30) of the mired adenocarcinomas. These data suggest that in some gastric adenocarcinomas, there is a defect in transport of E-cadherin to the cell surface, which may prevent intercellular adhesion and encourage dissemination. Of 34 cancers with paranuclear E-cadherin staining, 20 (59%) had paranuclear staining within the nonneoplastic epithelium, but only 22.0% of 100 carcinomas with absent or membranous E-cadherin staining were accompanied by morphologically benign epithelium with paranuclear E-cadherin. In surface epithelium, paranuclear E-cadherin staining colocalized with Griffonia simplicifolia lectin II in the Golgi apparatus. The presence of paranuclear E-cadherin in cancer-associated benign epithelium suggests that the alteration in the E-cadherin molecule responsible for the paranuclear distribution may be an early change in gastric adenocarcinoma progression.