Pancreas
Exocrine tumors / carcinomas
Intraductal oncocytic papillary neoplasm

Author: Deepali Jain, M.D. (see Authors page)

Revised: 13 December 2017, last major update August 2012

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Intraductal oncocytic papillary neoplasm[TIAB] pancreas

Cite this page: Jain, D. Intraductal oncocytic papillary neoplasm. PathologyOutlines.com website. http://pathologyoutlines.com/topic/pancreasiopn.html. Accessed December 15th, 2017.
Definition / general
  • First recognized in 1996 (Am J Surg Pathol 1996;20:980); also occurs in bile duct
  • WHO classifies as oncocytic type of IPMN, with complex and arborizing papillae with delicate stroma; papillae are lined by 2 - 5 layers of cuboidal to columnar cells with abundant eosinophilic granular cytoplasm; nuclei are round, large and fairly uniform and typically contain single, prominent, eccentrically located nucleoli
  • Mean age 62 years, no gender preference
  • Low malignant potential
  • Surgery may be curative
  • Invasive in 20%, usually limited in extent with nested oncocytic pattern
IPMN vs. IOPN
  • IPMN more often invasive (50% vs. 20%)
  • IPMN invades with a ductal or colloid pattern, not the oncocytic pattern of IOPN
  • IPMN usually have intestinal papillae, not the pancreaticobiliary type of IOPN
  • IOPN have intraepithelial lumina and are oncocytic
  • IOPN does not have KRAS mutation
Case reports
Gross description
  • Usually in head, mean 6 cm
  • Mucin filled cysts with nodular papillary projections
  • Often with dilated ducts communicating with main tumor
Gross images

Images hosted on other servers:

Partial gastrectomy, duodenum, pancreas, spleen and partial omentum;
pancreas shows solid area in head and multilocular lesion in tail with thick mucin
and soft grey brown luminal papillary masses (arrow); papillary mass also present
in ductus choledochus (arrowhead), close to the surgical resection margin (*)

Cystic mass in body of pancreas contains coagulated blood with fibrin, mucus and nodular papillary projection

Microscopic (histologic) description
  • Unilocular or multilocular papillary ducts composed of arborizing papillary structures with focal cribriform pattern, papillae lined by stratified and pseudostratified oncocytic cuboidal cells with intraepithelial lumina (highly specific, may contain mucin), abundant finely granular pink cytoplasm (due to mitochondria), prominent eccentric nuclei, microcystic spaces of 1 - 3 cell size (Stanford University: Intraductal Oncocytic Papillary Neoplasm of the Pancreas [Accessed 13 December 2017])
  • Architecturally complex with atypical cytology, mitotic figures, hyaline globules (negative for mucin) produce bud-like appearance (Pathol Int 2010;60:48)
  • Intraductal papillae may fuse and form large solid areas replacing the papillary architecture
  • Invasive component, if present, may resemble intraductal component
Microscopic (histologic) images

Images hosted on PathOut server:

Oncocytic carcinoma



Images hosted on other servers:

Various images

MUC6+ (fig C)


Arborizing papillae and invasive areas characterized by small nests of cells with extracellular mucin accumulation; invasion front composed of cells with abundant eosinophilic cytoplasm surrounded by abundant mucin; perineural invasion exists as a peritumoral desmoplastic stromal reaction


Fig a: cyst wall lined by columnar pancreas duct epithelium with papillary projections; fig b / c: tumor has variably complex, arborizing structures lined by plump cells with abundant eosinophilic cytoplasm; fig d: cytoplasm is positive for antimitochondrial antibody

Positive stains
Negative stains
  • p53, acinar cell markers (lipase, trypsin, chymotrypsin), neuroendocrine markers
Electron microscopy description
  • Cells frequently packed with mitochondria
Electron microscopy images

Images hosted on PathOut server:

Oncocytic carcinoma in pancreatic tail

Molecular / cytogenetics description