Abstract
A 76-year-old-man underwent EGD, and it revealed an elevated lesion, most of which was covered by duodenal mucosa with irregular central depression in the duodenal bulb. Well differentiated adenocarcinoma was suggested histopathologically from biopsy specimen. Therefore segmental resection of the duodenum was performed. Histologically, well differentiated adenocarcinoma arose within the background mucosa consisted of foveolar epithelium and fundic glands. Immunohisto-chemical examination was performed, and both the cancerous region and background mucosa were positive for MUC5AC and MUC6. Thus, this tumor was considered to be derived from ectopic gastric mucosa in the duodenal bulb. We report here a case of early primary carcinoma of the duodenal bulb arising from ectopic gastric mucosa.
