Gastro-esophageal reflux disease and Barrett's esophagus: an overview with an histologic diagnostic approach

Abstract

The first part of this overview on non-neoplastic esophagus is focused on gastro-esophageal reflux disease (GERD) and Barrett's esophagus. In the last 20 years much has changed in histological approach to biopsies of patients with gastro-esophageal reflux disease. In particular, elementary histologic lesions have been well defined and modality of evaluation and grade are detailed, their sensitivity and specificity has been evaluated and their use has been validated by several authors. Also if there is not a clinical indication to perform biopsies in patient with GERD, the diagnosis of microscopic esophagitis, when biopsies are provided, can be performed by following simple rules for evaluation which allow pathologists to make the diagnosis with confidence. On the other hand, biopsies are required for the diagnosis of Barrett's esophagus. This diagnosis is the synthesis of endoscopic picture (which has to be provided with the proper description on extent and with adequate biopsies number) and histologic pattern. The current guidelines and expert opinions for the correct management of these diagnosis are detailed.

Keywords: Barrett’s esophagus; gastro-esophageal reflux disease (GERD); histology; intestinal metaplasia of the cardia; microscopic esophagitis.

Figure 1.

Elementary lesion - increasing grades of severity in basal cell hyperplasia: A) normal, epithelium basal layer thickness is less than 15% of the entire thickness; B) mild basal cell hyperplasia ranges between 15% and 30%; C) severe basal cell hyperplasia: basal cells occupy more than 30% of whole epithelial thickness. Magnification 20x. Reprinted from ref. 10 with permission from Virchows Archiv, Springer Nature.

Figure 2.

Elementary lesion - increasing grades of severity in papillae elongation: A) normal papillae occupy less than 2/3 of the total epithelial thickness; B) mild papillae elongation does not exceed 75% of total epithelial thickness; C) marked papillae elongation with the upper limit of papillae approaching the epithelial surface. Magnification 20x. Reprinted from ref. 10 with permission from Virchows Archiv, Springer Nature.

Figure 3.

Elementary lesion - increasing grades of severity in dilated intercellular spaces (DIS): (A) in normal squamous epithelium, cells are sealed one with the other; (B) small, irregular DIS are shown close to a papilla; (C) large DIS with bubbles and ladders larger than the diameter of a small lymphocyte. Magnification 40x. Reprinted from ref. 10 with permission from Virchows Archiv, Springer Nature.

Figure 4.

Landmarks (GEJ and Z-line) and the Prague C&M system for reporting ESEM length: on the left side GEJ and Z-line coincide in normal case; on the right side Z-line is proximally dislocated with respect to GEJ and a C2M4 ESEM is represented. Artwork by Federica Grillo.

Figure 5.

Pictorial representation of the diagnostic algorithm taking into account endoscopic and histologic findings to correctly interpret the columnar lined esophagus. (A-C) Columnar cardia-type epithelium; (B) Columnar intestinal-type epithelium. BE: Barrett’s Esophagus. Artwork by Federica Grillo.