Intraductal Oncocytic Papillary Neoplasm
Mari Mino-Kenudson, MD
Key Facts
Terminology
Grossly cystic neoplasm with intraductal growth pattern and oncocytic epithelium
Clinical Issues
Rare entity with ˜ 40 cases reported in literature
Majority present with nonspecific symptoms or are discovered incidentally
5-year survival rate of noninvasive IOPN approaches 100%; invasive IOPN > 70%
Microscopic Pathology
Oncocytic epithelium that forms architecturally complex papillary growth pattern as well as areas of cribriforming and solid growth
Neoplastic cells have abundant granular eosinophilic cytoplasm with large nuclei, prominent nucleoli
Invasive carcinoma, often minimally invasive, present in 25-50%
 A tan-red luminal papillary mass  partially involves the dilated main pancreatic duct  . |
 IOPNs consist of architecturally complex, thick papillae, seen here growing in a dilated branch duct that is, in part, lined by relatively flat epithelium  . |
TERMINOLOGY
Abbreviations
Intraductal oncocytic papillary neoplasm (IOPN)
Intraductal papillary mucinous neoplasm (IPMN)
