Microscopic Colitis: Endoscopic Performance and Diagnostic Yield

Aims Colon biopsies for microscopic colitis (MC) are indicated for patients with chronic diarrhoea. However, there seems to be some discredit on its accomplishment. This can be justified by a subjective perception on a low frequency of MC diagnosed by random biopsies.

This study aims to evaluate the rate of biopsies for the diagnosis of MC and to evaluate their diagnostic yield.

Methods Retrospective study that included complete colonoscopies (with/without random biopsies) due to chronic non-bloody diarrhoea, and normal mucosa, between 2013 and 2019. Endoscopic and histological reports were analysed.

Results 174 complete colonoscopies were included (62.1 % women, mean age 59.7 ± 18 years). Random biopsies were performed in 61.5 % (n = 107) and ileoscopy in 30.5 % (n = 53). Biopsies were obtained in all segments in 91.5 % (n = 97), and in 8.41 % (n = 9) were not performed on the ascending colon.

There was a prevalence of 12.1 % of microscopic colitis (n = 13/107; 69.2 % men, mean age 58.69 ± 14.7 years). Most patients had biopsies in 2 bottles (left + right) or 4 bottles (4 segments) (38.5 % and 30.8 %, respectively). All patients had microscopic lymphocytic colitis, and it was diffusely distributed in 76.9 % of cases. Sigmoid and transverse were not affected in 3 patients (23.1 %). On average, each bottle had 2.8 fragments (range 1-8). Diagnostic performance did not depend on performance or performing physician (p > 0.05).

Conclusions The performance of random biopsies (61.5 %) for microscopic colitis diagnosis was low in this study. The prevalence of MC was not inferior to the one described by literature, but it may be underestimated. Microscopic colitis was prevalent in all ascending colon patients, but in 23.1 % it was not extended to distal segments. So, biopsies for the diagnosis of MC may eventually be performed only in the right colon.

Citation: Linhares M, Ramos D, Pereira F etal. eP270 MICROSCOPIC COLITIS: ENDOSCOPIC PERFORMANCE AND DIAGNOSTIC YIELD. Endoscopy 2021; 53: S187.

Publication History

Article published online:
19 March 2021