S3024 No Dermatologist Needed for This Collagen Filler: The Rare Presentation of Collagenous Gastritis in a Patient With Eosinophilic Esophagitis

Abstract

INTRODUCTION: Collagenous gastritis is a rare disease characterized by subepithelial collagen deposits within the gastric mucosa and chronic inflammation. While this disorder has similar histologic characteristics to the more common collagenous colitis, little is known about collagenous gastritis given its rarity. Fewer than 100 cases of collagenous gastritis have been reported to date, and our understanding of the disease is limited. The disease typically manifests with nonspecific symptoms including abdominal pain, diarrhea, and iron deficiency anemia (IDA). It is diagnosed histologically, and has been linked to various autoimmune disorders. We will describe a case of collagenous gastritis to further knowledge of this rare disease. CASE DESCRIPTION/METHODS: A 32-year-old man with a history of partial right lower lobectomy for carcinoid tumor 11 years prior, was referred for IDA, upper abdominal pain, and dysphagia. Initial endoscopy with biopsies revealed esophageal eosinophilia, consistent with eosinophilic esophagitis ( EoE). Gastroduodenal biopsies were unremarkable, and colonic biopsies revealed no collagenous or lymphocytic colitis. He was started on a PPI for 8-weeks and iron supplements, with improvement of symptoms. Following treatment, repeat EGD demonstrated resolution of his esophageal eosinophilia, and iron supplementation was discontinued. He re-presented 2 years later, with similar symptoms and recurrence of IDA. Repeat EGD demonstrated esophageal eosinophilia consistent with EoE. Endoscopy also revealed gastric erythema with nodularity (Figure 1), and subepithelial collagen deposition within the gastric body and fundus, consistent with collagenous gastritis (Fig 2a, 2b). He was restarted on iron supplement and a PPI, with improvement of symptoms. DISCUSSION: Collagenous gastritis has been associated with autoimmune disorders, and may be linked to EoE as described in this case. While diagnosis is histological, endoscopic features include gastric mucosal nodularity and erythema. Currently there is no clear consensus on the treatment of collagenous gastritis. Multiple therapies have been attempted including acid suppression, iron supplementation, hypoallergenic diets, among others, however to date there are no randomized control trials demonstrating treatment efficacy, and overall prognosis remains unclear. Awareness of this disorder is essential in its recognition. More information is needed to understand collagenous gastritis and determine how best to treat patients affected by this rare disease.Figure 1.: Endoscopic view of the gastric body, depicting moderately erythematous mucosa, with slight mucosal nodularity as seen (arrow).Figure 2a.: Gastric antrum/body endoscopic biopsy demonstrating thickened subepithelial collagen deposition (arrow) and inactive chronic gastritis. (H&E stain, 200x).Figure 2b.: Gastric antrum/body endoscopic biopsy with trichrome stain, demonstrating thickened subepithelial collagen. (Trichrome stain 2A, 200x).