A case of non-esophageal eosinophilic gastrointestinal disease diagnosed by mucosal incision-assisted biopsy.

A 46-year-old woman presented at our hospital with anorexia, vomiting, and diarrhea. Blood tests indicated markedly increased eosinophil counts, and esophagogastroduodenoscopy revealed slight erythema in the gastric body. Computed tomography showed edematous thickening of the stomach and small intestinal walls and peritonitis. Thus, eosinophilic gastrointestinal disease was suspected. Endoscopic biopsies from the esophagus, stomach, and duodenum were collected, but no significant increases in eosinophil counts were observed. Little ascites effusion was detected and puncture cytology was difficult to perform. Thus, a sample of the muscularis propria layer was obtained by mucosal incision-assisted biopsy. Histopathological examination of the biopsy revealed significant eosinophilic infiltration within the muscularis propria layer of the stomach, confirming the diagnosis of non-eosinophilic esophagitis eosinophilic gastrointestinal disease. The patient was treated with a leukotriene receptor antagonist and prednisolone, and her clinical symptoms and gastrointestinal wall thickening rapidly improved. The Japanese diagnostic guideline for non-eosinophilic esophagitis eosinophilic gastrointestinal disease requires endoscopic biopsy or eosinophilic infiltration of ascites fluid. When diagnosis is difficult using conventional methods, as in this case, mucosal incision-assisted biopsy is useful as a next step.