Reye Syndrome: Light and Electron Microscopic Studies of 7 Cases

ABSTRACT

Histopathological and electron microscopical studies were made on 7 cases of Reye syndrome. Histologically brain edema with neuronal degeneration and fatty change in the liver were constant findings, and fatty change of kidneys, heart and pancreas were variably observed. Electron microscopy revealed characteristic mitochondrial abnormalities in the hepatocytes, proximal convoluted tubular cells of kidneys, pancreatic acinar cells and nerve cells, in which the mitochondria were distended with expansion of matrix space and the matrix substance was converted to granular or flocculent material. Lipid droplets of small size were also observed in the various cells. In the hepatocytes abnormal shaped microbodies were noted and the rough endoplasmic reticulum was dilated. Virus-like particles were not found. It is suggested that Reye syndrome is not a rare disease-entity in Korea since the cases of Reye syndrome comprised 3.2 percent of all pediatric autopsies during the same period. The significance and the specificity of the mitochondrial changes in Reye syndrome are discussed.