Intraductal Oncocytic Papillary Neoplasm

 Often classified as having high-grade dysplasia given architectural complexity

• Neoplastic cells have abundant granular eosinophilic cytoplasm with large nuclei, prominent nucleoli

• Both intracytoplasmic and intercellular lumina found, many containing mucin, with scattered goblet cells

• Stroma can be edematous or myxoid at tip &/or base of papillae

• Invasive carcinoma, often minimally invasive, present in 25-50%

• Stain strongly with MUC6

• Variable staining with MUC1, MUC2, MUC5AC, CEA, CA19-9

Gross Appearance
A tan-red luminal papillary mass image partially involves the dilated main pancreatic duct image .

Dilated Branch Duct
Intraductal oncocytic papillary neoplasms (IOPNs) consist of architecturally complex, thick papillae, seen here growing in a dilated branch duct that is, in part, lined by relatively flat epithelium image .

Higher Magnification
Higher magnification of IOPN exhibits architecturally complex growth with cribriforming &/or solid nests. The neoplastic epithelial cells have abundant granular eosinophilic cytoplasm and large nuclei with prominent nucleoli.

MUC6 Expression
IOPNs demonstrate strong MUC6 expression.



• Intraductal oncocytic papillary neoplasm (IOPN)


• Grossly cystic neoplasm consisting of architecturally complex papillary intraductal growth of oncocytic (oxyntic) epithelium

• Grouped with intraductal papillary mucinous neoplasm (IPMN) in most recent WHO classification but considered distinct entity by others



• Incidence
image Rare entity with ∼ 40 cases reported in literature

Apr 20, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Intraductal Oncocytic Papillary Neoplasm

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