Advances in our understanding of cystic neoplasms of the pancreas

Our changing understanding of cystic abnormalities within the pancreas, and especially for cystic neoplasms of the pancreas, has led to a sea change in recognition, management, and interest in these lesions over the last 30 years. Unimagined improvements in cross-sectional imaging, better understanding of the natural biology, aggressiveness of mucinous versus serous epithelial neoplasms, and acknowledgment of the premalignant mucinous neoplasm led to tremendous interest in cystic neoplasms in all realms of pancreatology, including gastroenterologists, radiologists, pathologists, and surgeons alike. The introduction of evermore-sensitive imaging modalities, diagnostic maneuvers, and laboratory tests have led to new considerations in management, no longer limited to mucinous versus serous epithelial pathologies. The following unanswered questions remain: (1) How aggressively should small (<3 cm) asymptomatic lesions be approached and managed? (2) Are intraductal papillary mucinous neoplasms (IPMN) a localized field defect or a global abnormality potentially affecting the entire pancreatic ductal tree? (3) Does IPMN involve a different etiopathogenesis than the pancreatic intraepithelial neoplasia (PANin) progression? (4) Is there a familial form of IPMN involving a genomic or epigenetic change? and (5) Does the predilection to extrapancreatic neoplasms in patients with IPMN involve an underlying, more global genomic or epigenetic phenomena? This treatise will address these concepts.