Differentiating Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) may represent malignant or premalignant neoplasms and require diagnostic evaluation. Patient’s demographics and clinical presentation should be considered when diagnosing PCLs. Radiologically, location, ductal relation, external contour, wall, and septal enhancement give important clues for each type of lesion. Imaging features that suggest a high malignancy risk and warrant additional investigation are mural nodules, nearby mass, thick septa, and a dilated main pancreatic duct. Pseudocysts, intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and serous cystadenoma are the most frequently encountered cystic lesions. Pseudocysts are most likely to follow a history of pancreatitis and have high amylase and lipase values. Intraductal papillary mucinous neoplasms are usually connected to the pancreatic duct and are associated with a GNAS mutation. Mucinous cystic neoplasms generally present as a solitary distal cystic pancreatic lesion in a middle-aged woman and lack ductal communication. Serous cystadenomas are associated with high vascular endothelial growth factor levels and a VHL mutation and have a cyst content rich in glycogen. This review describes performance of various imaging modalities and pathological markers for diagnosing and detecting malignant potential of PCLs and illustrates typical pathological and radiological features of the most common PCLs, including primary issues in the differential diagnosis of these lesions.