Macroscopic Findings in Lymphocytic Colitis

Abstract

A57-year-old man with intermittent watery diarrhea for 6 weeks presented for colonoscopy. He denied any symptoms of blood or mucous in the stools, tenesmus, or severe abdominal pain. There was no weight loss, nausea, vomiting, or loss of appetite. Symptoms were stable for the last 6 weeks. Patient was hemodynamically stable without any evidence of dehydration or orthostasis. Abdominal examination was unremarkable with soft, nontender abdomen without any organomegaly. Prior evaluation was negative for stool Clostridium difficile, ova, and parasites. Colonoscopy was performed, which showed extensive linear “furrowed” mucosal pattern (Figure A), unassociated with trauma, extending from transverse colon to the rectum. The changes were more prominent in the distal colon and the rectum with elaborate mosaic pattern seen in the rectum (Figures B and C). Multiple random biopsies were taken with histology confirming lymphocytic colitis (Figure D). Patient was treated conservatively with resolution of symptoms. Lymphocytic colitis is a type of microscopic colitis characterized by watery diarrhea and increased subepithelial lymphocytes on colon biopsies. Typically, it is associated with a normal endoscopic appearance. Recently, case reports have described evidence of macroscopic abnormalities in patients with microscopic colitis, with most cases being collagenous colitis. To our knowledge, this is the first case describing a “furrowed” and “mosaic” mucosal pattern that may be seen in patients with lymphocytic colitis. Lymphocytic colitis may not be all that microscopic after all!