A Tale of Two Colitides

Abstract

Inflammatory bowel disease (IBD) and microscopic colitis (MC) are two distinct subgroups within the larger group of colitides. MC could manifest as collagenous colitis (CC) or lymphocytic colitis (LC). The co-occurrence of MC in patients with IBD is rare, with few cases reported. No concurrent case of MC and ulcerative colitis (UC) each presenting with distinct clinical manifestations was found in the literature review. We report a case of a 76-year-old male presenting with concurrent CC and UC. The patient's initial flare of UC was characterized by episodes of bloody diarrhea while his flare of CC was evidenced by watery diarrhea.

Keywords: chronic colitis; crohn’s disease (cd); inflammatory bowel disease; microscopic colitis; ulcerative colitis (uc).

Figure 1. Left colon biopsy from 2019. This is a hematoxyloin and eosin stain showing glandular architectural distortion, crypt abscess formation, and increased lamina propria lymphocytes and plasma cells with basilar accentuation demonstrating inflammatory bowel disease.

Figure 2. Sigmoid colon biopsy from 2021 with Masson Trichrome stain showing mildly thickened subepithelial collagen band, irregular at its base, with entrapped small capillary vessels and red blood cells. Focal surface epithelial attenuation and damage are noted as a mild background glandular architectural distortion from the quiescent inflammatory bowel disease.

Figure 3. Right colon biopsy from 2019 with trichrome stain showing UC and CC.

UC, ulcerative colitis; CC, collagenous colitis