Pancreatic cysts are increasingly diagnosed due to the widespread prevalence of radiologic imaging for unrelated conditions. Although there are many uncommon types of pancreatic cysts (solid pseudo papillary neoplasms, cystic lymphangioma), pancreatic cysts can be classified broadly as either malignant/premalignant (intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm or malignant degeneration of a solid tumor (adenocarcinoma, endocrine)) or low/no malignant potential (pancreatic pseudo cyst or serous cystadenoma). For IPMNs arising predominantly from the main pancreatic duct (main duct IPMN), there is a very high risk of coincident cancer. For IPMN arising from the branches of the pancreatic duct (branch duct IPMN), the risk of having or developing cancer is much lower than main duct IPMN. Mucinous cystic neoplasms typically occur in the pancreatic body and tail in middle aged women and carry a high risk of malignancy. Pancreatic pseudocysts typically arise in the setting of acute pancreatitis but often no history of pancreatitis is available at the time of presentation. Serous cystadenoma is predominantly microcystic lesions often with a central stellate scar on imaging. They are often asymptomatic but may present abdominal discomfort or biliary obstruction.
The presumptive diagnosis of pancreatic cysts is made based on a combination of clinical (previous history of pancreatitis), radiologic, endoscopic (gaping “fish mouth ampulla”) of IPMN, endosonographic and pancreatic cyst fluid analysis. Typically elevated pancreatic cyst fluid CEA > 192 mg/ml favors a mucinous lesion such as an IPMN or an MCN ( with an 80% accuracy), but the absolute cyst fluid CEA level does not correlate with the presence of malignancy. A very low CEA (<5 ng/ml) is seen in patients with serous cystadenoma.
All presumed main duct IPMN (MD-IPMN) and MCNs should be considered for surgical resection based on the extend of pancreas involvement. For branch duct IPMNs, surgical resection should be considered for patients with symptoms referable to their pancreatic cyst, for pancreatic cyst size >3 cm, and for pancreatic cyst size < 3 cm when there is associated evidence of a focal mass or a dilated pancreatic duct. Otherwise yearly surveillance with a combination of MRI or CT is indicated for these presumed branch duct IPMN. For presumed serous cystadenomas, surgical resection is indicated for symptomatic cysts such as abdominal pain or biliary obstruction. Symptomatic pancreatic pseudocysts can be drained endoscopically, percutaneously or surgically.
At the Yale Pancreas Disease Program, we offer expert multidisciplinary evaluation, diagnosis, and treatment of patients with pancreatic cystic neoplasms and pseudocyst.