New York-Presbyterian/Weill Cornell Medical Center New York, NY
Benjamin Gordon, MD1, Alyson Kaplan, MD1, David Wan, MD2; 1New York-Presbyterian/Weill Cornell Medical Center, New York, NY; 2Weill Cornell Medical College, Cornell University, New York, NY
Introduction: Collagenous colitis (CC) is a syndrome of chronic noninfectious watery diarrhea. As its designation as a microscopic colitis suggests, CC has minimal, if any, endoscopic findings. Here, we report the case of a woman with watery diarrhea, found to have severe colonic ulcers on colonoscopy, with pathology consistent with CC.
Methods: A 55-year-old woman with type 1 diabetes mellitus and Hashimoto’s thyroiditis presented with non-bloody watery diarrhea for a month. She was empirically treated for small intestinal bacterial overgrowth and Giardia. Yet, stool fat, gastrointestinal pathogen PCR panel, C. difficile toxin PCR, and celiac serologies were negative. She had no improvement and thus, returned to the hospital. Medications included insulin and levothyroxine. Exam showed lower abdomen tenderness. Laboratory studies were notable for WBC 13.2, Hb 13.4, CRP 6.7, ESR 27, fecal calprotectin > 1250, and repeat negative infectious stool studies, including Giardia and ova/parasites. CT abdomen/pelvis demonstrated diffuse wall thickening and mucosal hyperenhancement, most prominent in the descending colon through rectum. Flexible sigmoidoscopy showed multiple petechiae, ulcerations and severely altered vascular mucosa in the descending and sigmoid colon (Images 1, 2). Pathology was consistent with CC with patchy erosions and focal pseudomembranes (Image 3). The patient was started on steroids with marked improvement within days. Discussion: CC is one of the two major microscopic colitides, characterized by chronic non-bloody watery diarrhea and less often weight loss and abdominal pain. It has a female predominance and up to half of patients have autoimmune conditions. No laboratory value is specific, but anemia and elevated inflammatory markers are common. As a microscopic colitis, CC typically appears normal endoscopically, with most patients having no macroscopic changes. In those with endoscopic findings, they tend to be subtle, including mucosal erythema/edema or abnormal vascular pattern. Major endoscopic findings, such as those found in our patient, include mucosal ulcers, mucosal fractures/tears and cat-scratch mucosa, occurring in less than 2% of CC patients. Thus, CC remains a histologic diagnosis. In conclusion, though this case has a classic presentation and risk factors for CC, gross endoscopic changes make it an unexpected diagnosis, reinforcing the importance of pathology to properly diagnose patients with colonic ulcers.
Multiple petechiae and ulcerations are found in the descending colon.
Severely abnormal vascular pattern is seen in the sigmoid colon.
Pathology showed collagenous colitis with patchy erosions and focal pseudomembranes.
Disclosures: Benjamin Gordon indicated no relevant financial relationships. Alyson Kaplan indicated no relevant financial relationships. David Wan indicated no relevant financial relationships.