Pancreas
Exocrine tumors / carcinomas
Intraductal oncocytic papillary neoplasm


Topic Completed: 7 April 2020

Minor changes: 7 April 2020

Copyright: 2012-2020, PathologyOutlines.com, Inc.

PubMed Search: Intraductal oncocytic papillary neoplasm[TIAB] pancreas

Gokce Askan, M.D.
Olca Basturk, M.D.
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Cite this page: Askan G, Basturk O. Intraductal oncocytic papillary neoplasm. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreasiopn.html. Accessed August 8th, 2020.
Definition / general
  • Intraductal pancreatic lesion with papillary architecture and characteristic oncocytic epithelium
  • First described in 1996 by Adsay et al (Am J Surg Pathol 1996;20:980)
  • 2019 WHO recognizes as a distinct type of intraductal neoplasm
  • Accounts for 4.5% of intraductal neoplasms of the pancreas (Pancreas 2016;45:1233); also occurs in bile ducts (Surg Today 2012;42:1240)
Essential features
  • A rare and distinct type of intraductal neoplasm of pancreas
  • Distinctive cytologic features are oncocytic cells with large prominent nucleoli
  • Less mucin production than intraductal papillary mucinous neoplasms (IPMNs)
  • Lack genetic alterations commonly seen in IPMN
  • Indolent behavior even if associated with invasive carcinoma
Terminology
  • Intraductal oncocytic papillary neoplasm
  • Older term is oncocytic type of intraductal papillary mucinous neoplasm (WHO 2010)
ICD coding
    ICD-O:
  • 8455/2 - Intraductal oncocytic papillary neoplasm NOS
  • 8455/3 - Intraductal oncocytic papillary neoplasm with associated invasive carcinoma
Epidemiology
Sites
Etiology
  • No known etiological factors
Clinical features
Radiology description
  • Complex mass with both solid and cystic components that may lead to misdiagnosis of pancreatic ductal adenocarcinoma (Cancer Cytopathol 2016;124:122)
Prognostic factors
Case reports
Treatment
  • Treated primarily by surgical resection
Gross description
  • Cystic with friable papillary or exophytic nodular projections often within the main pancreatic duct
  • Median size 4.5 cm (Am J Surg Pathol 2019;43:656)
Microscopic (histologic) description
  • Multilocular or unilocular cysts containing complex and arborizing papillae with delicate ļ¬brovascular cores (Virchows Arch 2016;469:523)
  • Papillae are lined by multiple layers of neoplastic cells with voluminous granular oncocytic cytoplasm and prominent, large, eccentric nucleoli (Cancer Cytopathol 2016;124:122)
  • Cribriform structure and intraluminal mucin formation are not uncommon
  • Papillae may fuse and form solid growth pattern
  • Invasive carcinoma is seen in about 30% of cases (Am J Surg Pathol 2019;43:656)
  • True invasion seen in different patterns: small infiltrative tubules, mucinous and solid nests of oncocytic cells (Am J Surg Pathol 2019;43:656)
  • Tangential sectioning may mimic true invasion (Am J Surg Pathol 2019;43:656)
  • Abrupt transition from a normal epithelium to oncocytic epithelium, within the same duct, favors pseudoinvasion
Microscopic (histologic) images

Contributed by Gokce Askan, M.D. and Olca Basturk, M.D.
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Unilocular or multilocular cystic lesion

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Papillae lined by oncocytic epithelium

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Intracytoplasmic vacuoles

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MUC6

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Pseudoinvasion


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Tubular invasion pattern

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Mucinous invasion pattern

Cytology description
Cytology images

Images hosted on other servers:
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Oncocytic cell sheets with prominent nucleoli

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Punched out spaces, intracytoplasmic mucin

Electron microscopy description
Molecular / cytogenetics description
Sample pathology report
  • Pancreas and duodenum, pancreaticoduodenectomy:
    • Intraductal oncocytic papillary neoplasm of pancreass (IOPN) (see comment)
    • Comment: The pancreas was submitted entirely for microscopic evaluation and no associated invasive carcinoma is identified. The neoplasm involves the main pancreatic duct. The neoplasm measures 3.5 cm in greatest dimension. Adjacent pancreas reveals atrophy. Surgical margins are free of neoplasm. Twelve benign lymph nodes are identified (0/12).
    Differential diagnosis
    Board review answer #1
      Which of the following is true about intraductal oncocytic neoplasms of pancreas (IOPNs)?

    1. Cribriform structure is one of the most common histologic features
    2. They commonly occur in the tail of the pancreas
    3. They exhibit indolent behavior even if associated with invasive carcinoma
    4. They have mucin production as much as seen in intraductal papillary mucinous neoplasms (IPMNs)
    5. They have same genetic alterations that commonly seen in intraductal papillary mucinous neoplasms (IPMNs)
    Board review answer #1
    C. They exhibit indolent behavior even if associated with invasive carcinoma

    Comment Here

    Reference: Intraductal oncocytic papillary neoplasm
    Board review style question #2
      Which one of the following is positive in intraductal oncocytic neoplasms of pancreas (IOPNs)?

    1. Chromogranin
    2. Chymotrypsin
    3. MUC6
    4. Synaptophysin
    5. Trypsin
    Board review answer #2
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