Intraductal papillary-mucinous neoplasms: a new and evolving entity among the pancreatic tumors.

: The intraductal papillary-mucinous neoplasms of the pancreas have only recently been recognized as a clinical and pathological entity. They show an adenoma-carcinoma sequence, but have a much more favorable prognosis than ductal adenocarcinoma. Moreover, it has become clear that they constitute a heterogeneous group with at least four histopathological subtypes that have different biological properties with different prognostic implications.