More recently, it has been reported that intraductal papillary neoplasms of the bile duct [25], [26], pyloric gland adenoma of the stomach and duodenum [27], and low grade appendiceal mucinous neoplasms [28] resembled IPMN histologically and that these neoplasms had a high frequency of GNAS mutations. This evidence concerns the gene GNAS and bile duct papillary neoplasm.