Esophageal Polypoid Dysplasia of Gastric Foveolar Phenotype With Focal Intramucosal Carcinoma Associated With Barrett's Esophagus

Abstract

We describe a rare case of esophageal polypoid dysplasia with gastric phenotype and focal intramucosal carcinoma associated with Barrett's esophagus. A 69-year-old man with a long history of gastroesophageal reflux disease was initially seen at an outside institution for evaluation of significant dysphagia. Screening upper gastrointestinal endoscopic evaluation revealed a large intraluminal polypoid lesion occluding the distal portion of the esophagus. Surgery was performed with resection of the distal esophagus and proximal stomach. The histopathologic examination of this lesion revealed an exuberant polypoid gastric epithelium with areas of low-grade dysplasia, high-grade dysplasia, and focal intramucosal carcinoma. A few residual foci of specialized intestinal metaplasia consistent with Barrett's esophagus without dysplasia were identified at the proximal and distal ends of the lesion. Immunohistochemically, this lesion revealed a pattern of expression of apomucins (MUC5AC diffusely positive, MUC1 and MUC6 focally positive, and MUC2 negative) consistent with a gastric foveolar phenotype. In addition, in the dysplastic areas, there was high Ki-67 labeling index and no overexpression of p53 protein. In our opinion, this case represents a precursor lesion of an extremely well-differentiated adenocarcinoma of gastric foveolar phenotype that has been previously documented in the stomach and in the duodenum and that now for the first time we report in the esophagus in association with Barrett's intestinal metaplasia.