Histopathologic features of eosinophilic esophagitis and eosinophilic gastrointestinal diseases.

Eosinophilic esophagitis (EoE) shows characteristic microscopic pathologic features in endoscopically obtained esophageal biopsies, including an eosinophil-rich inflammatory infiltrate in esophageal epithelium, but other inflammatory cells are also increased. Additional alterations are found in epithelium and lamina propria. Esophageal biopsy pathology is a sensitive but not specific marker for EoE related to antigen exposure. Several of the pathologic features of EoE correlate with dysregulated genes in the EoE transcriptome. Eosinophilic gastrointestinal diseases affecting the remainder of the gastrointestinal tract are less well characterized; this article discusses pathologic features in mucosal biopsies that could form the basis for diagnosis and future study.