Clinico-pathological Evaluation of Chronic Diarrhea with Microscopic Colitis: A Cross-sectional Study

Abstract

Introduction: Chronic diarrhea is common in the older population accounting for 7-9 % which often markedly affects their quality of life. The causes are many and include infectious, endocrine, metabolic, neoplastic, functional, drugs. Microscopic Colitis (MC) has emerged as a distinct diagnostic entity, where the colon appears endoscopically normal, but the biopsy reveals characteristic features in the mucosa. It has two histological forms i.e, Collagenous Colitis (CC) and Lymphocytic Colitis (LC). Aim: To study the clinico-pathological spectrum of lesions in random colonic biopsies of patients with chronic diarrhea having normal colonoscopy. Materials and Methods: This cross-sectional study was conducted in Department of Pathology at JSS Hospital, Mysuru, Karnataka, India, from October 2017 to September 2019. Multiple random biopsies were taken from 80 patients with chronic diarrhea who had normal colonoscopy. The slides were stained with Hematoxylin and Eosin (H&E) and Masson’s Trichrome Stain (MTS). The histological features were studied under light microscopy and using computer-assisted image analysis. The Chi-square test was used to statistically analyse the data. Results: The age of patients ranged from 11-82 years with a mean age of 43 years. Out of total 80 patients, 65 (81.25%) of the cases had non specific inflammation, 14 (17.4%) had microscopic colitis and one patient (1.25%) had probable eosinophilic colitis. The histological features were observed in computer-assisted image analysis using morphometry and interpreted by two pathologists with agreement. Conclusion: Random biopsies are required for the diagnosis of microscopic colitis in the absence of macroscopic abnormalities on colonoscopy, which may affect the treatment strategy. A histologic examination combined with histochemical stain MTS and interpretation utilising computerized image analysis program with morphometry is more effective in cases with diagnostic uncertainty.