Identification and analysis of precursors to invasive pancreatic cancer.

Precursor lesions of pancreatic cancer have been recognized about a century ago. The development of a consistent reproducible nomenclature and classification system for these lesions has been a major advance in the study of these noninvasive precursors. Pancreatic intraepithelial neoplasia (PanIN) as microscopic precursor lesions can be distinguished from mucinous cystic neoplasms (MCNs) and intraductal papillary mucinous neoplasms (IPMN) that are cystic and can often be recognized on imaging. Since precursor lesions harbor the unique chance to treat a patient before a fatal pancreatic cancer can arise a molecular characterization is essential to understand the biology and to find diagnostic and therapeutic targets to fight this disease of near uniform lethality. In order to study precursor lesions on a molecular level a meticulous isolation of the neoplastic cells is inevitable. We present the salient histopathologic and molecular features of precursor lesions of pancreatic cancer as well as methods that have proved to be useful within experimental studies.