There are a large number of reports in the literature that patients with dermatomyositis often have various malignant tumors, and reports of gastric cancer are not rare. At present, the widely recognized gastric cancer occurrence patterns are: normal gastric mucosa-chronic superficial gastritis-chronic atrophic gastritis-intestinal metaplasia-dysplasia-gastric cancer, so the research about the gastric mucosal performance of patients with dermatomyositis is clinically meaningful

Inclusion Criteria:

• 1、18-70years old，no gender limit. 2、Clinical diagnosis of dermatomyositis. 3、dermatomyositis group conform to 1 and 2，control group conform to 1 .

Exclusion Criteria:

• Contraindications for gastroscopy.

  • Past history of malignant tumors of the esophagus and stomach and or history of surgery.

    • Pregnant or lactating women. ④ Participated in other clinical studies within 3 months. ⑤Patients cannot express their main complaints correctly and cannot cooperate with the research.

Dermatomyositis patients in the Department of Rheumatology, the Second Affiliated Hospital of Zhejiang University School of Medicine。 Healthy people undergoing physical examination at the Physical Examination Center of the Second Affiliated Hospital of Zhejiang University School of Medicine。