Demographic features and diagnostic criteria of Primary Eosinophilic Colitis among adult patients with emphasis on clinicopathological correlation

Abstract

Objective Primary Eosinophilic Colitis (PEC) is the rarest and least understood entity in the spectrum of eosinophilic gastrointestinal diseases. This study aims at describing the clinicopathological characteristics of this disease and to explore histological criteria that can improve its diagnostic accuracy. Methods: In this retrospective clinico-pathological study, we describe the clinical and histological features of 22 cases of PEC. The computerized system of the Histopathology Department at Jordan University Hospital was searched for cases diagnosed as tissue eosinophilia (130 cases). The medical records were reviewed to check the final diagnosis and only cases with PEC were included. The demographic features were documented, and all the histopathological slides were reviewed and the main histological features, mainly the number of eosinophils per high power field were recorded. Results: 16.9% of cases of tissue eosinophilia turned out to be PEC. These were distributed equally between genders with the median age being 49.5 years. The most common presentation was diarrhea and/or abdominal pain. Colonoscopy was normal in 72.7 % of cases. 40.9% of Patients had associated allergic conditions, mostly milk intolerance, and 18.2 % had peripheral eosinophilia. Histologically there was dense eosinophilic inflammation with features of eosinophil activation including degranulation and eosinophilic cryptitis and crypt abscesses. There was no correlation between the density of the eosinophilic infiltrate and these histological features. Conclusion: Gastroenterologists and pathologists should keep a high index of suspicion when faced with cases of unexplained diarrhea and/ or abdominal pain. Pathologists reporting colonic biopsies should actively search for eosinophils in the colonic biopsies when faced with such history. However, diagnosis cannot be made on histological grounds alone, and clinico-pathological correlation is essential to diagnose PEC after excluding all possible secondary causes.