Primary pancreatic cystic neoplasms revisited. Part III. Intraductal papillary mucinous neoplasms.

Intraductal papillary mucinous neoplasms (IPMNs) represent about 25% of all primary pancreatic cystic neoplasms and are increasingly recognized during the last two decades. They are characterized by intraductal proliferation of neoplastic mucinous cells forming papillary projections into the pancreatic ductal system, which is typically dilated and contains globules of mucus. IPMNs may be multifocal and have malignant potential. Modern imaging is essential in establishing preoperative diagnosis and in differentiating different subtypes of IPMNs (i.e., main-duct vs. branch-type disease). Endoscopic retrograde or magnetic resonance cholangiopancreatography accurately delineate the morphologic changes of the pancreatic ductal system. Endoscopic ultrasonography (usually used in conjunction with image-guided FNA and analysis of the aspirated material) is commonly used for differential diagnosis of IPMNs from other pancreatic cystic lesions. Surgical resection (usually anatomic pancreatectomy, depending on the location of the disease) is the treatment of choice. Total pancreatectomy may occasionally be required in selected patients, but is associated with formidable long-term morbidity. A conservative approach has recently been proposed for carefully selected patients with branch-duct IPMNs. Recurrences following surgical resection can be observed, especially in patients with multifocal disease or in the presence of underlying malignancy.