• Fibrosis begins as zone 3 perivenular/pericellular (chicken wire) fibrosis (with exception of pediatric patients); may progress to bridging fibrosis, cirrhosis
• If portal inflammation is accentuated, think of advanced disease or concomitant chronic liver disease
• Nonalcoholic steatohepatitis in pediatric population has different injury pattern
Inflammation, fibrosis accentuated in portal region
Ballooning degeneration and perisinusoidal fibrosis not obvious
Macrovesicular Steatosis Macrovesicular steatosis is common in nonalcoholic steatohepatitis (NASH). It frequently begins in zone 3, particularly in adults, and may extend to become panzonal.
Hepatocyte Ballooning Ballooned hepatocytes are common in NASH and may be associated with Mallory-Denk bodies. Note the steatosis and glycogenated nuclei as well.
Pericellular Fibrosis Trichrome stain highlights the pericellular fibrosis that is typical of steatohepatitis and NASH. In adults, the fibrosis typically begins in zone 3.
Glycogenated Nuclei Glycogenated nuclei , featuring clear, vesicular nuclei within hepatocytes, are a common, but nonspecific, finding in NASH.
TERMINOLOGY
Abbreviations
• Nonalcoholic steatohepatitis (NASH)
Definitions
• Steatosis, inflammation, and ballooning in absence of history of alcohol use
ETIOLOGY/PATHOGENESIS
Mechanism
• Hepatic accumulation of lipids provides source of oxidative stress and leads to injury/inflammation
• Subsequent activation of TGF-β and hepatic stellate cells results in fibrosis
are common in NASH and may be associated with Mallory-Denk bodies. Note the steatosis and glycogenated nuclei as well.
, featuring clear, vesicular nuclei within hepatocytes, are a common, but nonspecific, finding in NASH.
