An autopsy case (55-year-old man) of congestion of the liver, resulted from acute myocardial infarction, with severe vacuolar degeneration and hyaline protein droplets in the hepatocytes was reported, and the relationship between vacuolar degeneration and hyaline protein droplets was also discussed. It is well known that hyaline protein droplets are rarely recognized, although vacuolar degeneration is frequently observed, in the human livers. Pathogenesis and morphogenesis of vacuolar degeneration have been clarified by us, but those of hyaline protein droplets are still obscure. It is, however, thought that hyaline protein droplets relate closely to vacuolar degeneration, because hyaline protein droplets coexist with vacuolar degeneration in many cases and both lesions consist of blood plasma. In the present case, transition from vacuolar degeneration to hyaline protein droplets and many hyaline protein droplets being present in vacuoles were observed. Accordingly, we believed that vacuolar degeneration was present prior to the formation of hyaline protein droplets and some factor, e.g. condensation and other unknown metabolic process, is essential to formation of hyaline protein droplets from vacuolar degeneration.
