Reply to Kadayifci and Brugge

We thank Drs. Kadayifci and Brugge for their valuable comments. They discussed the utility of performing endosonography-guided fine-needle aspiration (EUS-FNA) for the differential diagnosis of cystic lesions in the pancreas. We agree that the differential diagnosis of pancreatic cystic lesions can be aided by analyzing fluids for carcinoembryonic antigen and amylase levels, and by performing cytology, GNAS mutation analysis, and confocal endomicroscopy [1] [2] [3]. In our study [4], patients with branch duct intraductal papillary mucinous neoplasms (IPMNs; cystic lesions connected to the pancreatic duct) underwent surgery because they had symptoms, mural nodules, or concomitant pancreatic ductal adenocarcinomas (PDACs). Pathological diagnosis of all of the resected cystic lesions connected to the pancreatic duct showed that they were branch duct IPMNs. During the same study period, some patients who had pancreatic cystic lesions that were not connected to the pancreatic duct underwent surgery; however, in these cases, the cystic lesions consisted of serous cystic neoplasms, mucinous cystic neoplasms, branch duct IPMNs, and other types of cystic lesions. In other words, the differential diagnosis of cystic lesions that are not connected to the pancreatic duct is difficult and sometimes requires interventional diagnostic methods [1] [2] [3], as mentioned by Drs. Kadayifci and Brugge.