Abstract
A 63-year-old man underwent esophagogastroduodenoscopy, which revealed a type 0-Is lesion (indefinite for neoplasia), 5mm in size, in the superior duodenal angle. Four years later, the lesion increased in size to 7mm, and it was diagnosed as suspected adenocarcinoma at endoscopic biopsy. It was considered to be a mucosal lesion in the endoscopic ultrasound performed one month later. Therefore, we decided to resect it by endoscopic treatment. Two months later, at the time of treatment, the lesion had changed to 0-IIa+IIc-type. En bloc resection was performed using the endoscopic mucosal resection technique. Histopathological examination of the resected specimen verified well-differentiated tubular adenocarcinoma, SM. We report a very rare case of early duodenal cancer showing morphological change in a short period of two months.
