intraductal tumors of the pancreas

There are three types of pancreatic neoplasms that predominantly have an intraductal growth pattern:
 the common, usually cystic, intraductal papillary mucinous neoplasm (IPMNs);
 the rare, usually solid intraductal tubulopapillary neoplasm (ITPNs);
 and the rare intraductal tubular pyloric gland-type adenoma .

In addition to these three tumor types, pancreatic neoplasms with a usually solid growth pattern such as acinar cell carcinomas, neuroendocrine tumors, and undifferentiated carcinomas may present, though very rarely, as predominantly intraductally growing neoplasms.

IPMNs

Intraductal papillary mucinous neoplasms (IPMNs) can be subclassified into main duct and branch duct tumors; into low- and high-grade dysplasia groups; and into tumors with intestinal, pancreatobiliary, oncocytic, or gastric cellular differentiation.

The intestinal-, pancreatobiliary-, and oncocytic-type IPMNs occur predominantly in the main duct of the head of the pancreas and more commonly progress to invasive adenocarcinomas.

The gastric-type IPMNs are frequently multifocal, occur predominantly in the branch ducts of the uncinate process, and have a low risk of progressing to invasive carcinoma.

The prognosis for patients with an IPMN depends largely on the subtype and the presence and the stage of an invasive carcinoma. ITPNs are nodular tumors, often in the pancreatic head, and composed of densely packed tubular glands.

Molecular genetics reveal KRAS, GNAS, and RNF43 as the most frequently mutated genes in IPMNs, while ITPNs show wild-type KRAS.

See also

 intraductal tubulopapillary neoplasm (ITPN) of the pancreas

References

 http://www.semdiagpath.com/article/S0740-2570(14)00079-3/fulltext