p53 immunoreactivity in Barrett's metaplasia, dysplasia, and adenocarcinoma--a case report.

Barrett's esophagus is a condition in which the stratified squamous epithelium of the esophagus is replaced by a columnar epithelium with malignant potential. Mutations of the tumor-suppressor gene p53 have been implicated in the evolution of esophageal carcinomas. The aim of this study was to determine whether p53 immunoreactivity in Barrett's esophagus is a marker of neoplasia and, if so, when it occurs in the metaplasia-dysplasia-carcinoma sequence. We treated a patient with esophageal carcinoma arising from the Barrett's esophagus. Consecutive evidence existed for a metaplasia-dysplasia-carcinoma in the same specimen. Immunohistochemical staining with the monoclonal antibody was used to detect the intranuclear protein product of mutated p53. No p53 immunoreactivity was seen in specimen of Barrett's mucosa. p53 immunoreactivity was found only in specimen of dysplasia and carcinoma. Immunoreactivity occurs late in the metaplasia-dysplasia-carcinoma sequence, during the transition to high-grade dysplasia.