Reye Syndrome

 Most often seen in children

image Classic syndrome involves combination of resolving viral illness and salicylate therapy


• Pathogenesis unknown

• Mitochondrial injury is a key feature

• Frequent antecedent viral infection

• Salicylate exposure appears to play role although no causal connection proven

Clinical Issues

• Clinical picture dominated by neurologic rather than hepatic manifestations
image Clinical evidence of hepatic disease may be very subtle

• Biphasic pattern: Viral prodrome followed by neurologic manifestations
image Prodromal febrile illness

image Vomiting and neurologic alterations 3-5 days later

• Mortality ∼ 30%
image Death usually due to cerebral edema and complications


• Diffuse, panlobular microvesicular steatosis

• No significant inflammation

Top Differential Diagnoses

• Congenital metabolic conditions

• Acute fatty liver of pregnancy

• Alcoholic foamy degeneration

• Drug/toxin-mediated injury

• Sepsis

Diagnostic Checklist

• Presumptive diagnosis can be made based on clinical and laboratory findings

• Microvesicular fatty change in context of neurologic alterations/encephalopathy

• Necessity of liver biopsy for diagnosis is controversial

Microvesicular Steatosis
Diffuse microvesicular steatosis image and occasional acidophil bodies image are seen in a case of Reye syndrome. Cholestasis is rare in this disorder.

Absence of Portal Inflammation
An intact portal tract with no portal inflammation is seen in a biopsy from a patient with Reye syndrome. Portal inflammation is typically absent. Diffuse background microvesicular steatosis is also seen.

Microvesicular Steatosis
Microvesicular steatosis is characteristic of Reye syndrome. Numerous tiny fat vacuoles surround the hepatocyte nucleus image, which retains its central location within the hepatocyte. This change can be subtle and may be mistaken for hepatocyte swelling or an artifact.

Microvesicular Steatosis on Electron Microscopy
This electron micrograph shows numerous lipid droplets image within a hepatocyte in a patient with Reye syndrome. (Courtesy E. Sengupta, MD.)



• Acute and potentially life-threatening disorder characterized by fatty liver and encephalopathy
image Most common in infants and children under 17 years

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Apr 20, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Reye Syndrome

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