Increased mucosal eosinophils in colonic diverticulosis and diverticular disease

Aims Eosinophils contribute to tissue homeostasis, damage, and repair. The mucosa of colonic diverticula has not been evaluated for eosinophils by quantitative histology. We aimed to investigate whether mucosal eosinophils and other immune cells are increased in colonic diverticula. Methods Hematoxylin and eosin stained sections from colonic surgical resections (n = 82) containing diverticula were examined. Eosinophils, neutrophils, and lymphocytes, in five high power fields in the lamina propria were counted at the base, neck, and ostia of the diverticulum and counts compared to non‐diverticula mucosa. The cohort was further subgrouped by elective and emergency surgical indications. Results Following an initial review of 10 surgical resections from patients with diverticulosis, a total of 82 patients with colonic resections containing diverticula from the descending colon were evaluated (median age 71.5, 42 M/40F). Eosinophil counts for the entire cohort were increased in the base and neck (median 99 and 42, both P =