Atypical histological features of ulcerative colitis

The diagnosis of ulcerative colitis is based on combination of clinical, endoscopic and pathological findings. However cases have been reported showing atypical endoscopic and histological features in ulcerative colitis. Hence the objective of this study was to determine the atypical features of new onset ulcerative colitis in adult population.

A total 110 newly diagnosed cases of ulcerative colitis were enrolled in the study over a period of five years. The diagnosis of ulcerative colitis was made by correlating clinical, endoscopic and histological features. Biopsies from representative areas were processed routinely. Endoscopic and histological evaluation was carried out for atypical features.

Majority of the patients (75.4%) were between 21-50 years of age with male to female ratio of 2.2:1. A significant number of patients showed atypical endoscopic findings in the form of rectal sparing in 12 (10.9%) and skip lesions in 24 (21.8%) patients. Atypical features noted on histology included normal surface epithelium in 8 (7.3%), predominant polymorphs in 42 (38%), predominant eosinophils in 7 (6.3%), normal crypt architecture in 1 (0.9%) and well preserved goblet cells in 30 (28%) cases.

A significant number of patients with new onset ulcerative colitis showed atypical pattern of disease endoscopically as well as histologically. Pathologists should be aware of these atypical findings in cases of ulcerative colitis so as to avoid misdiagnosis.