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