It depends on what the cyst is. There are 4 kinds of pancreatic cysts that may be cancer. They are serous cystadenoma, mucinous cystadenoma, intraductal papillary mucinous neoplasm (IPMN), and papillary cystic tumor. The likelihood of the latter 2 become cancer is very high. You should frequently monitor the cysts according to your physician's advice.