A 63-year-old man with no past medical history was referred to our hospital for treatment of an esophageal adenocarcinoma. The endoscopic biopsy of the short segment Barrett's esophagus (SSBE) at the previous hospital showed poorly differentiated adenocarcinoma. Laboratory data showed no abnormal values, including tumor markers, such as CEA and CA19-9. On contrast-enhanced computed tomography, there was no evidence of metastasis to lymph nodes or other organs. Esophagogastroduodenoscopy (EGD), performed at our hospital 3 months after the first EGD, revealed an 8-mm reddish depressed region at the esophagogastric junction (EGJ). Magnifying narrow-band imaging endoscopy (ME-NBI) showed an invisible mucosal pattern and visible and irregular vascular patterns. The vascular irregularities did not have a mesh or loop pattern, which are commonly seen in Barrett's adenocarcinoma; instead, they had a wavy micro-vessel pattern, which are observed in gastric undifferentiated carcinoma (Fig. 1). Considering that the lesion was present in a patient with SSBE and the previous doctor's biopsy showed poorly differentiated adenocarcinoma, we diagnosed the lesion as suspicious for Barrett's adenocarcinoma. Endoscopic submucosal dissection (ESD) was performed 5 months after the first EGD. When ESD was