[Eosinophilic esophagitis: the diagnostic contribution of pathology]

Eosinophilic esophagitis is a chronic, clinically and histologically defined, inflammatory condition of the esophagus. The histological hallmark of eosinophilic esophagitis is a relevant, often patchy infiltration of the esophageal mucosa with eosinophils. In a consensus report a threshold value of approximately 120 eosinophils per mm(2) was arbitrarily fixed as a diagnostic criterion. Noteworthy for the quantification of the eosinophilic infiltration are several technical facts, for instance size and covering extent of the biopsy specimen of the high-power field (hpf) and quality of embedding of biopsy specimens have to be considered. In order to establish the histological diagnosis several additional abnormalities must be included in the assessment and gastrointestinal reflux disease is the main differential diagnosis of eosinophilic esophagitis. Finally it is emphasized that for an affirmative diagnosis of eosinophilic esophagitis, in addition to the histological findings the clinical facts must be included.