Background/aims: The aim of this study was to investigate the specificity and sensitivity of eosinophil cutoff points defining the colonic tissue eosinophilia (TE) and compare the yield of reporting the highest count versus the mean of five high-power fields (HPFs).
Materials and methods: One hundred and seventy-one cases of colonic TE, including 22 primary eosinophilic colitis (PEC) cases, were compared to one hundred and twenty-one normal controls in the University of Jordan. The highest eosinophil count (EC) and the mean of five HPFs were recorded. The receiver operating characteristic curve (ROC) analysis was used to find the cutoff point with the best sensitivity and specificity.
Results: There was no significant advantage of counting five fields over counting the most densely populated HPF. Using 30 eosinophils per HPF achieved 80% sensitivity and 65% specificity. This point is close to the mean in normal controls plus one standard deviation (SD) (29 per HPF). However, there was overlap between normal counts and TE, using 30 as a cutoff point resulted in 35% false-positive rate. There was no reliable cutoff point to differentiate PEC from secondary TE.
Conclusion: We recommend reporting the highest EC in colonic biopsies and using 30 as a cutoff point, bearing in mind the overlap with normal and correlating with the clinical team to not treat asymptomatic patients. Clinicopathological correlation is essential to separate PEC from secondary TE.
Keywords: Colon; eosinophils; primary eosinophilic colitis; tissue eosinophilia.
Conflict of interest statement
Distribution and variability of esophageal eosinophilia in patients undergoing upper endoscopy.Mod Pathol. 2015 Mar;28(3):383-90. doi: 10.1038/modpathol.2014.110. Epub 2014 Sep 12. Mod Pathol. 2015. PMID: 25216228 Free PMC article.
Primary Colonic Eosinophilia and Eosinophilic Colitis in Adults.Am J Surg Pathol. 2017 Feb;41(2):225-233. doi: 10.1097/PAS.0000000000000760. Am J Surg Pathol. 2017. PMID: 27792062
Eosinophilic gastritis: histopathological characterization and quantification of the normal gastric eosinophil content.Mod Pathol. 2011 Apr;24(4):556-63. doi: 10.1038/modpathol.2010.221. Epub 2010 Dec 17. Mod Pathol. 2011. PMID: 21169993
Eosinophilic colitis and colonic eosinophilia.Curr Opin Gastroenterol. 2019 Jan;35(1):42-50. doi: 10.1097/MOG.0000000000000492. Curr Opin Gastroenterol. 2019. PMID: 30480590 Review.
Diagnosing eosinophilic colitis: histopathological pattern or nosological entity?Scientifica (Cairo). 2012;2012:682576. doi: 10.6064/2012/682576. Epub 2013 May 9. Scientifica (Cairo). 2012. PMID: 24278727 Free PMC article. Review.
- Conner JR, Kirsch R. The pathology and causes of tissue eosinophilia in the gastrointestinal tract. Histopathology. 2017;71:177–99. - PubMed
- Samiullah, Bhurgri H, Sohail U. Eosinophilic disorders of the gastrointestinal tract. Prim Care. 2016;43:495–504. - PubMed
- Alfadda AA, Storr MA, Shaffer EA. Eosinophilic colitis: An update on pathophysiology and treatment. Br Med Bull. 2011;100:59–72. - PubMed
- Silva J, Canao P, Espinheira MC, Trindade E, Carneiro F, Dias JA. Eosinophils in the gastrointestinal tract: How much is normal? Virchows Arch. 2018;473:313–20. - PubMed