Subclinical course of cholesterol ester storage disease (CESD) diagnosed in adulthood. Report on two cases with remarks on the nature of the liver storage process.

An extremely benign variant of cholesterol ester storage disease (CESD) was diagnosed in two female patients aged 43 and 56 years. In one of them the course was entirely subclinical until a stroke at the age of 47, most probably a complication of secondary hyperlipoproteinaemia. The diagnosis was made accidentally in vivo during extensive examination for concomitant monoclonal gammapathy. The other patient (aged 56), still displays a fairly stable course with minor dyspeptic symptoms. The clinical findings in both patients were confined to moderate well tolerated hepatomegaly, hyperlipoproteinaemia of IIb type and xanthelasmata. Acid lipase activity was markedly deficient in peripheral leukocytes and cultured fibroblasts. These cases represent a rare adult variant the existence of which should be borne in mind in the differential diagnosis of chronic liver disease in advanced age and of hyperlipoproteinaemic states. The diagnostic criteria for the routine clinicopathological steps are summarized with emphasis on a special lipopigment deposition pattern, encompassing inhibition and modification of lipofuscin generation in hepatocytes and an excess of ceroid production in both portal and intralobular histiocytes. The varied ultrastructural appearance of the lysosomal limiting membrane complex is described.