Intraductal Papillary Mucinous Neoplasm

Intraductal Papillary Mucinous Neoplasm

Mari Mino-Kenudson, MD

In IPMN, main-duct type, the markedly dilated main duct image shows nodular mucosa with abundant mucin (stained with yellow dye). The ampullary orifice is indicated image.

IPMN, branch-duct type, features a small cyst with a smooth lining image connected to the main pancreatic duct image through a dilated branch duct image.



  • Intraductal papillary mucinous neoplasm (IPMN)


  • Grossly visible, mucin-producing epithelial neoplasm that primarily grows within main duct &/or its branches

  • Subclassification based on type of duct involvement

    • Main-duct type

      • Mucinous epithelium confined to main pancreatic duct

    • Combined type

      • Mucinous epithelium involving both main duct and branch ducts

    • Branch-duct type

      • Mucinous epithelium confined to branch ducts



  • Incidence

    • Most common cystic tumor of pancreas

      • Approximately 8-20% of all resected pancreatectomy specimens

  • Age

    • Range: 25-94 years

      • Average: 63 years

  • Gender

    • Slightly more common in men


  • Symptoms associated with intermittent pancreatic ductal obstruction

    • Abdominal pain

    • Back pain

    • Anorexia

    • Weight loss

    • Recurrent episodes of pancreatitis

  • Symptoms often present for months to years before diagnosis is established

  • Growing number of cases discovered incidentally during imaging for another indication

Endoscopic Findings

  • Mucin extravasation from patulous ampulla of Vater


  • Surgical resection is treatment of choice

    • 80-98% of IPMNs are surgically resectable


  • Noninvasive tumors: 5-year survival rate > 75%

  • Invasive tumors: 5-year survival rate is significantly lower (34-62%) than for noninvasive tumors

    • Still significantly better than that of conventional pancreatic ductal adenocarcinoma


CT Findings

  • Main-duct or combined type

    • Markedly dilated main duct often associated with dilated large branch ducts

  • Branch-duct type

    • Single or numerous cysts that represent dilated branch ducts

ERCP Findings

  • Dilated main pancreatic duct &/or branch ducts in absence of stricture

  • Filling defects due to papillary projections of neoplasm &/or mucous plugs

MRCP Findings

  • In addition to dilated ducts, mural nodules are better visualized

    • Indicative of higher grade lesion


General Features

  • Most common in pancreatic head

    • Often involve only a portion of pancreatic duct

    • Some are multifocal

    • Entire gland may be involved

  • Main-duct and combined types

    • Florid papillary projections, often in background of dilated ducts

  • Branch-duct type

    • Single or multiple peripheral cysts that connect to main duct, often with smooth lining

  • Mural nodules &/or solid components may be seen in IPMNs with invasion


Histologic Features

Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Intraductal Papillary Mucinous Neoplasm

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