Primary pancreatic cystic neoplasms revisited: part II. Mucinous cystic neoplasms.

Mucinous cystic neoplasms (MCNs) of the pancreas represent one of the most common primary pancreatic cystic neoplasms, accounting for approximately half of these cases. MCNs are observed almost exclusively in women, and most commonly are located in the body/tail of the pancreas. In contrast to SCNs, MCNs have malignant potential. Proliferative changes (hyperplasia with or without atypia, borderline changes, non-invasive or carcinomas in-situ, and invasive carcinomas) can often be observed within the same neoplasm. Several risk factors for the presence of underlying malignancy within an MCN have recently been recognized. Cross-sectional imaging is of key importance for the diagnostic evaluation of patients with a cystic pancreatic lesion. Cyst fluid examination (cytology, biochemical/genetic analysis) is possible by using fine needle aspiration of the MCN, usually under endoscopic guidance, and may provide useful information for the differential diagnosis. Since MCNs have malignant potential, surgical resection is the treatment of choice.