A child who was given aspirin died , pathological autopsy done,which shows the characteristic feature which can be used for making diagnosis of death. This feature is ?

Reye syndrome occurs most often in small children after an acute febrile illness that has been treated with aspirin. It presents with hepatic failure and encephalopathy, but the pathogenesis of this syndrome and its relation to aspirin are not understood. The liver biopsy consistently shows microvesicular steatosis(fatty change). Electron microscopy reveals changes in liver mitochondria.