Liver and intrahepatic bile ducts - tumor
Benign tumors/conditions
Mucinous cystic neoplasm (MCN)


Topic Completed: 1 October 2019

Revised: 10 December 2019

Copyright: 2019, PathologyOutlines.com, Inc.

PubMed Search: Mucinous cystic neoplasm (MCN) AND (free full text[sb])

Zachary Dong, M.D.
Kimberley J. Evason, M.D., Ph.D.
Page views in 2019: 351
Page views in 2020 to date: 379
Cite this page: Dong Z, Evason KJ. Mucinous cystic neoplasm (MCN). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/livertumorMCN.html. Accessed April 1st, 2020.
Definition / general
  • Cystic hepatic neoplasm with ovarian type stroma and mucinous epithelium that does not communicate with bile ducts
  • Usually benign (90%) (Mod Pathol 2011;24:1079) but may be associated with invasive carcinoma
Essential features
  • Multiloculated cystic neoplasm lined by biliary type or mucinous epithelial cells overlying ovarian type stroma
  • Complete surgical excision with extensive sampling for histology is required to reduce risk of recurrence and determine if associated invasive carcinoma is present
Terminology
  • Hepatobiliary cystadenoma
  • Hepatobiliary cystadenocarcinoma (if associated invasive carcinoma)
  • Biliary cystadenoma
  • Cystadenoma with mesenchymal stroma
ICD coding
    ICD-11:
  • 2E92.6 - benign neoplasm of gallbladder, extrahepatic bile ducts or ampulla of Vater
  • XH6NK7 - mucinous cystic neoplasm with low grade intraepithelial neoplasia
  • 2E61.Y - carcinoma in situ of other specified digestive organs
  • XH81P3 - mucinous cystic tumor with high grade dysplasia
  • 2C15.1 - mucinous cystic neoplasm with associated invasive carcinoma of distal bile duct
  • 2C18.1 - mucinous cystic neoplasm with associated invasive carcinoma of perihilar bile duct
  • 2C17.1 - mucinous cystic neoplasm with associated invasive carcinoma of other or unspecified parts of biliary tract

    ICD-0:
  • 8470/0 (page 64) - mucinous cystic neoplasm with low grade intraepithelial neoplasia
  • 8470/2 (page 65) - mucinous cystic neoplasm with high grade intraepithelial neoplasia
  • 8470/3 (page 65) - mucinous cystic neoplasm with associated invasive carcinoma
Epidemiology
Sites
  • Liver parenchyma
  • May rarely involve extrahepatic bile ducts or gallbladder
Pathophysiology
  • Ovarian type stroma may originate from developing gonads due to their close proximity to the liver during embryologic development (Dig Surg 2010;27:19)
Etiology
  • Unknown at this time
Clinical features
  • Typically present with abdominal pain and swelling
  • May have symptoms of biliary obstruction (jaundice)
Diagnosis
  • Fine needle aspiration and imaging studies cannot reliably distinguish mucinous cystic neoplasms from other types of liver cysts
  • Definitive diagnosis requires histopathologic confirmation of the ovarian type stroma, usually after surgical excision (Am J Surg Pathol 2018;42:95)
Laboratory
  • Serum CA19-9 may be elevated, especially if invasive carcinoma is present
Radiology description
Radiology images

Images hosted on other servers:
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CT with cystic mass

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CT with large lesion

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Cholangiogram

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Ultrasound

Prognostic factors
  • Complete surgical excision confers a favorable prognosis
  • Prognostic significance of invasive component is difficult to determine, as many reported cases with invasive carcinoma lack ovarian type stroma, occur in men and thus may represent intraductal papillary neoplasm rather than mucinous cystic neoplasm (Am J Surg Pathol 1994;18:1078)
Case reports
Treatment
  • Complete surgical excision
  • Incomplete excision is associated with local recurrence and risk of malignant transformation (World J Surg 2006;30:1560)
Gross description
  • Cystic with multiple communicating lobules of varying sizes with a smooth and glistening lining (J Surg Case Rep 2012;2012:5)
  • Cystic fluid usually clear and thin
  • Sampling should focus on areas of wall thickening / nodules, with potentially submitting the entire lesion
Gross images

Images hosted on other servers:
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Gross findings

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Cystic lesion

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Thin walled cystic mass

Microscopic (histologic) description
  • Multiloculated cysts lined by columnar, cuboidal or flattened biliary type or mucinous epithelial cells overlying ovarian type stroma (Am J Surg Pathol 2018;42:95)
  • Ovarian type stroma consists of densely packed, spindle-shaped to oval cells that may be focally luteinized
  • Should be sampled extensively to rule out high grade dysplasia (frequent mitotic figures, nuclear pleomorphism, complex tubulopapillary projections, etc.) and invasive carcinoma (usually ductal adenocarcinoma)
  • Epithelium of larger lesions can become traumatized, showing ulceration, inflammation with xanthogranulomatous reaction, extravasation of cyst fluid into the wall or stroma or scarring and calcifications
Microscopic (histologic) images

Contributed by Kimberley J. Evason, M.D., Ph.D.
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Cystic lesion

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Ovarian stroma

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Columnar epithelium

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PR

Cytology description
  • Few groups of bland, degenerated, columnar or cuboidal epithelial cells (Cancer 2002;96:37)
  • Inflammatory background (neutrophils, lymphocytes, macrophages) (Cancer 2002;96:37)
  • Stromal components (including ovarian type stroma) usually absent
  • Cyst fluid can be assayed for carcinoembryonic antigen and CA19-9 to help distinguish mucinous neoplasms from non neoplastic lesions
Cytology images
  • Not available at this time
Positive stains
Negative stains
Sample pathology report
  • Liver, left lobe, lobectomy:
    • Mucinous cystic neoplasm
    • No high grade dysplasia or invasive carcinoma present
Differential diagnosis
  • Endometriosis
    • Also may have cystically dilated spaces lined by columnar to cuboidal epithelium and surrounded by spindled cellular stroma
    • ER+ in both epithelium and stroma, whereas MCNs are ER+ only in stroma
    • Typically has stromal iron laden macrophages and CK10 positivity, whereas the stroma in MCNs is CK10-, inhibin+ and often more cellular
  • Intraductal papillary neoplasm (IPN)
    • Has dilated bile ducts that may resemble cystic space(s) of MPN
    • May be lined by biliary type epithelium, like MPN
    • Typically communicates with bile duct, unlike MPN
    • Lacks ovarian type stroma
  • Simple cyst, simple hepatic cyst, simple biliary cyst, bile duct cyst
    • Is lined by biliary type epithelium, like MCN
    • Lacks ovarian type stroma
Board review style question #1

    Which of the following is true about this liver lesion?

  1. It usually communicates with intrahepatic bile ducts
  2. The epithelium is usually CK20+
  3. The stroma is usually ER / PR-
  4. There is a strong female predominance
  5. These lesions are most commonly multifocal
Board review answer #1
D. There is a strong female predominance (this is a mucinous cystic neoplasm)

Comment Here

Reference: Mucinous cystic neoplasm (MCN)
Board review style question #2
    Mucinous cystic neoplasms of the liver most often occur

  1. After the sixth decade of life without sex predominance
  2. In association with invasive carcinoma
  3. In males before the 3rd decade of life
  4. Multifocally and associated with bile ducts
  5. With abdominal pain as the most common presenting symptom
Board review answer #2
E. With abdominal pain as the most common presenting symptom

Comment Here

Reference: Mucinous cystic neoplasm (MCN)
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