Liver & intrahepatic bile ducts

Dysplasia

Low grade dysplastic nodule



Topic Completed: 25 January 2021

Minor changes: 26 January 2021

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PubMed search: Low grade "dysplastic nodule" liver


Naziheh Assarzadegan, M.D.
Raul S. Gonzalez, M.D.
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Cite this page: Assarzadegan N, Gonzalez RS. Low grade dysplastic nodule. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/livertumorlowgradedysplasticnod.html. Accessed December 2nd, 2021.
Definition / general
  • Discrete nodules in cirrhotic livers containing mild architectural changes
Essential features
  • Dysplastic nodules (both low grade and high grade) are associated with higher risk of development of hepatocellular carcinoma
  • Low grade dysplastic nodules have a significantly lower risk to transform into carcinoma than high grade nodules (J Hepatol 2003;39:208)
Terminology
  • Also called macroregenerative nodule type I, adenomatous hyperplasia, hepatocellular pseudotumor
Clinical features
  • Usually ages 40 and older; 67% arise in males
  • May progress to hepatocellular carcinoma but usually stabilize or disappear over time instead
Radiology description
  • Usually isovascular or hypovascular compared to surrounding parenchyma, whereas hepatocellular carcinoma appears hypervascular
Treatment
  • Follow by imaging
Gross description
  • Often distinct nodules (can be vague), separated from the surrounding liver by a rim of thin fibrous scar (not a true capsule)
  • Usually multiple, 0.5 to 1.5 cm, occasionally up to 5 cm
  • Similar in color and texture to surrounding liver; may be pale or bile stained
  • Usually found in cirrhotic livers, rarely in acute liver injury or precirrhotic livers
Microscopic (histologic) description
  • Monotonous cell population lacking architectural atypia, with mild increase in cellularity compared to surrounding cirrhotic liver (Hepatology 2009;49:658, Dig Liver Dis 2011;43:S361)
  • Portal tracts can be identified within the nodules
  • Liver cell plates 1 - 2 cells thick (highlighted on reticulin stain)
  • Features of hepatocellular carcinoma (pseudoglands or markedly thickened trabeculae) absent
  • May have large cell changes in hepatocytes
  • Unpaired arteries, which have no accompanying bile ducts, can be prominent in number and size (unlike cirrhotic nodules)
  • May have diffuse iron or copper retention (Arch Pathol Lab Med 2011;135:704)
Microscopic (histologic) images

Contributed by Naziheh Assarzadegan, M.D.

Mild increase in
cellularity compared
to surrounding
cirrhotic liver



Images hosted on other servers:

Low grade dysplastic nodules

Molecular / cytogenetics description
  • May be clonal
  • Inactivation of p21 checkpoint in contrast to cirrhotic nodules, which show activation
Sample pathology report
  • Liver, native, orthotopic transplantation:
    • Cirrhosis with mild chronic inflammation and three low grade dysplastic nodules (see comment)
    • Negative for high grade dysplasia or malignancy.
    • Margins of resection unremarkable.
    • Comment: The findings are consistent with the patient’s reported history of chronic hepatitis C infection. A trichrome stain confirms cirrhosis. An iron stain is unremarkable.
Differential diagnosis
Board review style question #1
Which of the following is true about low grade dysplastic nodules in the liver?

  1. If unresected, they will always progress to hepatocellular carcinoma
  2. They are grossly distinct from background cirrhotic nodules
  3. They are hypervascular radiologically
  4. They have prominent architectural atypia histologically
Board review style answer #1
B. They are grossly distinct from background cirrhotic nodules

Comment Here

Reference: Low grade dysplastic nodule
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