Pancreas, Intraductal papillary mucinous neoplasm

Pancreatic cysts are common in adult patients (up to 25% in some autopsy studies). While most of these are benign pseudocysts, those with a mucinous lining are important to recognize (either by imaging or cytologic sampling) because they are precursors to invasive carcinoma. The two major types of pancreatic mucinous cysts are IPMNs, which communicate directly with the pancreatic ductal system, and mucinous cystic neoplasms, which generally are not in continuity with the ducts. IPMNs can be further classified into 4 subcategories based on the predominant cytology (gastric, intestinal, pancreatic-biliary, and oncocytic). This is an example of an oncocytic type IPMN with high grade dysplasia. These lesions have a high risk for associated invasive carcinoma.