Collagenous gastroduodenocolitis in a Korean adolescent: first pediatric case report in Asia

Abstract

Collagenous gastritis (CG) is a rare disease diagnosed histologically by the subepithelial deposition of collagen bands thicker than 10 µm and the infiltration of inflammatory mononuclear cells in the lamina propria. The definite pathophysiology is yet to be elucidated. However, recent studies have suggested that the collagen deposition may be the result of a reparative process in response to an earlier inflammatory, autoimmune, infectious, or toxic insult. CG is divided into the pediatric- and adult-type. While the pediatric-type is limited to the stomach, the adult-type involves not only the stomach but also the intestine and/or colon. We report a rare case of adult-type CG in a 15-year-old boy who initially presented with abdominal pain and iron-deficiency anemia. Esophagogastroduodenoscopy (EGD) revealed findings suspicious for Helicobacter pylori (H. pylori) gastritis. Although histology did not reveal the organism, campylobacter-like organism (CLO) test was positive. Based on the diagnosis of suspicious H. pylori gastritis, eradication was conducted using the triple drug regimen. However, symptoms of intermittent abdominal pain persisted and diarrhea newly developed one year later. Histologic results from biopsies from the stomach, duodenum, and colon revealed findings compatible with CG, collagenous duodenitis (CD), and collagenous colitis (CC). This is the first pediatric case of collagenous gastroduodenocolitis (CGDC) reported in Asia. It is no longer assumed that adult-type and pediatric-type CG should be classified as an independent disease, but should be considered as similar diseases on a continuous spectrum. Therefore, children and adolescents diagnosed with CG should also consider undergoing a colonoscopy for the evaluation of possible coexisting CC when concurrent lower gastrointestinal symptoms are present. Moreover, considering the possibility of negative findings on the first endoscopy, repeat endoscopy should be considered when symptoms persist.

Keywords: Case report; collagenous colitis (CC); collagenous duodenitis (CD); collagenous gastritis (CG); colonoscopy.

Figure 1

Medium to large sized gastric ulcers in the cardia with diffuse nodular hyperplasia were observed on EGD. EGD, esophagogastroduodenoscopy.

Figure 2

Microscopic images of the mucosal biopsy specimen from the stomach antrum. (A) A dense irregular eosinophilic band is noted below the gastric surface epithelium measuring 60 µm (double headed arrow), and there is chronic inflammation in the lamina propria (H&E, ×200). (B) The thickened subepithelial layer stain blue with Masson trichrome stain (×200). (C) Congo red stains are negative (×200).

Figure 3

Histopathological examination of colon biopsy shows acellular collagenous dense bands (double headed arrow) underneath the epithelium, measuring 30 µm in thickness (H&E, ×200).