Temporal changes in the histology of microscopic colitis

Area of Science:

• Gastroenterology
• Histopathology
• Colorectal Diseases

Background:

• Microscopic colitis (MC) can exhibit histopathological shifts between lymphocytic colitis (LC) and collagenous colitis (CC).
• Previous research indicates potential transitions between MC and inflammatory bowel disease (IBD).

Purpose of the Study:

• To determine the prevalence of histopathological transitions within microscopic colitis (MC).
• To investigate the frequency of phenotype changes between MC subtypes and inflammatory bowel disease (IBD).

Main Methods:

• Cross-sectional analysis of histopathology records from the Inform Diagnostics database.
• Evaluation of 4363 MC patients with at least two colonoscopies between 2008 and 2020.
• Prevalence calculated per 100 MC patients with 95% Poisson confidence intervals.

Main Results:

• 1.6% of MC patients shifted from LC to CC, and 0.5% from CC to LC.
• 9.5% of MC patients also had IBD diagnoses; 2.9% showed synchronous MC and IBD.
• 2.1% of MC cases transitioned to IBD, and 4.5% of IBD cases transitioned to MC.

Conclusions:

• The study confirms the coexistence and transitions between microscopic colitis (MC) and inflammatory bowel disease (IBD).
• Gastroenterologists should consider underlying phenotype changes in patients with treatment-resistant MC or IBD.