Immunohistochemical presentation in non-malignant and malignant Barrett's epithelium

Barrett's esophagus, which is histologically characterized by metaplastic columnar epithelium, is a common condition observed in approximately 10-20% of patients with gastroesophageal reflux disease. These lesions can typically progress from metaplasia with atypia to low-grade dysplasia, high-grade dysplasia, and adenocarcinoma. It is of great clinical importance to correctly grade these lesions and to identify changes with a high risk of malignant transformation, inasmuch as high-grade dysplasias and early adenocarcinomas in patients with Barrett's esophagus have a high chance for cure. The identification of high-risk lesions in Barrett's esophagus by histologic evaluation has drawbacks, especially regarding sampling errors and frequent intra- and interobserver discrepancies in the histopathologic grading/staging of these lesions. Immunostaining with a variety of antibodies provides a better understanding of the process of malignant transformation and helps to identify early markers of malignant transformation in Barrett's esophagus lesions. In this review, we will summarize the current knowledge about the value of immunostaining in the diagnosis of malignant and non-malignant Barrett's epithelium and its role to better define lesions with high risk for malignancy in this disorder.