Cystic and ductal tumors of the pancreas: diagnosis and management.

Incidentally discovered cystic tumors of the pancreas (CTP) are an increasingly frequent entity. It is essential to differentiate lesions whose malignant potential is either nil or negligible (pseudocyst, serous cystadenoma, simple cysts) from lesions with intermediate malignant potential (intraductal papillary mucinous tumor of the pancreas [IPMN] involving the secondary ducts, cystic endocrine tumor) or those with high malignant potential (mucinous cystadenoma, solid pseudopapillary tumors and IPMN involving the main pancreatic duct). The approach to defining malignant potential is based on diagnostic CT scan, magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS), often complemented by EUS-guided cyst puncture for biochemical and cytological analysis of cyst fluid. Surgery for diagnostic purposes should be avoided because of its significant morbidity. For pseudocysts, simple cysts and serous cystadenomas, abstention is the general rule. Resection, preserving as much pancreatic parenchyma as possible, is the rule for IPMN involving the main pancreatic duct, mucinous cystadenomas, solid and pseudopapillary tumors, and cystic endocrine tumors. Resection is rarely indicated at the outset for IPMN involving secondary pancreatic ducts; morphologic observation is the general rule and preventive excision may be indicated secondarily. Good collaboration between surgeons, radiologists and endosonographists is necessary for optimal management of CTP.