Steatohepatitis

Steatohepatitis is a fatty change of the liver and is due to a number of different causes.

Steatohepatitis
Diagnosis in short
Treatment	dependent on underlying cause

General

• Steatohepatitis is a label for a set of histopathologic findings.
• Fat accumulation in hepatocytes.
  • It may be a pattern seen in drug toxicity, e.g. methotrexate toxicity.

Etiology:

1. Alcohol = alcoholic steatohepatitis (ASH).
2. Not alcohol = non-alcoholic steatohepatitis (NASH).
3. Drug/toxin.

Notes:

• Pathologists can comment on the etiology; however, the histomorphology is not distinctive. In other words, ASH and NASH are clinical diagnoses.
• Steatohepatitis is a misnomer. It is not an -itis; inflammation is not the (predominant) pathologic process.

Microscopic

Features:

• Steatosis (usually macrovesicular) - key feature.
  • If less than 10% ... consider alt. diagnosis/disease process.
• Hepatocyte injury:
  • Ballooning degeneration - key feature (see introduction to liver).
  • Mallory bodies.
    • Mallory body wannabes: "occasional cytoplasmic clumping".
• +/-Chicken-wire perisinusoidal fibrosis +/- zone III (centrilobular) fibrosis (early).
  • Late-stage disease - portal bridging.

DDx:

• Wilson disease.
• Hepatitis C.
• Drug-induced liver disease.

Grading steatohepatitis

Grading inflammation:

• Grade 1 - steatosis, occasional ballooning degeneration, PMNs.
• Grade 2 - obvious ballooning, obvious PMNs, chronic inflammation.
• Grade 3 - panacinar steatosis.

Image

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  Steatohepatitis. (WC)

See also

• Medical liver disease.
• Alcohol abuse.