A Caucasian American patient with celiac disease diagnosed in Japan and successfully treated with a gluten-free diet.

We report the case of a 33-year-old Caucasian American man diagnosed with celiac disease in Japan. He presented to a community hospital because of chronic watery diarrhea and weight loss for 6 months. The laboratory data showed low serum albumin and serum cholesterol. A colonoscopy was normal. He was referred to our hospital for further work-up. Serum tissue transglutaminase immunoglobulin A (IgA) and endomysial antibody were positive. The HLA type was DQ2. Esophagogastroduodenoscopy (EGD) revealed nodular and mosaic-patterned mucosa from the bulb to the second part of the duodenum. The histopathological findings were consistent with Marsh type 3c of the modified Marsh classification for celiac disease. The patient was instructed to follow a gluten-free diet (GFD). Six months after the initiation of the GFD, his symptom and the levels of serum albumin and cholesterol were improved, and the serum tissue transglutaminase IgA and endomysial antibody became negative. However, EGD showed little improvement. Capsule endoscopy also revealed mosaic-patterned mucosa, nodular mucosa, and scalloping of the folds of the duodenum and proximal small intestine. There was no definite improvement in histopathological findings. Collectively, the GFD was effective in this patient with celiac disease, but it should be maintained to achieve endoscopic and histopathologic healing.