Papillary mucinous neoplasia (IPMN) was firstly described by Ohashi et al. in 1982. These kind of tumors of the
exocrine pancreas represent a group of ductal lesions, that only in 1996 were incorporated into the WHO classification. The lesions
may arise from the dysplasia and the invasive carcinoma as well and are characterized by intraductal papillary growth, mucin production
and cystic dilatation of the pancreatic ducts. IPMNs are cystic tumors involving the main pancreatic duct and/or the branch ducts. There are
three wide kinds of IPMNs, according to the extent of duct involvement:principal duct, secondary branches or mixed presentations.
Pancreas divisum (PD) has been recognized to be the most common congenital variant of the pancreas, consisting of a defect of
fusion between the ventral and the dorsal ducts. As a result, the major drainage of the pancreas comes from the dorsal duct, which flows into
the minor papilla, while the ventral duct drains the less part of it and flows into the major papilla. An incomplete PD may arise in some cases.
In this condition, only a narrow connection joins the ventral and the dorsal ducts, but most of the pancreatic drainage takes place through
the minor papilla.
Last date updated on July, 2014