Liver cell adenoma in a neonate--report of an autopsy case.

A case of liver cell adenoma that was incidentally found at postmortem examination of a neonate who died of E. coli sepsis is described. The adenoma was a sharply demarcated, not encapsulated mass located subcapsularly in the right lobe, and was pale tan to light yellowish round nodule of 0.9 cm in diameter. Microscopically, the tumor was composed of sheets and cords of uniform and slightly enlarged hepatocytes separated by dilated sinusoids. There were no portal zones or central veins to suggest the normal lobular architecture. The nuclei were bland and the cytoplasm varied from clear to acidophilic, containing lipid vacuoles. Ultrastructural examination showed that the hepatocytes of the tumor had highly differentiated organelles, reminiscent of normal hepatocytes.