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