Pathology of the liver in Reye's syndrome.

A study of six patients with Reye's syndrome indicated that, by light microscopy, inflammation and necrosis of liver cells are especially prominent in fatal cases. Contrary to previous reports, electron microscopic examination indicated that, aside from loss of matrix dense granules, alterations in mitochondrial structure were minimal or absent. Although an increase in the number of liver cell microbodies has been reported, no such increase was apparent in the present study. The most unusual ultrastructural change in microbodies in the present study was the appearance of noncrystalline cores in the matrix. No ultrastructural features served to distinguish patients who died from those who survived. Although derangement of mitochondrial function may be important in the pathogenesis of Reye's syndrome, such derangement is not necessary reflected in the ultrastructure of mitochondria.