Progressive macrophage accumulation in lysosomal acid lipase deficiency

Lysosomal acid lipase (LAL) deficiency (LAL-D) is a lysosomal lipid storage disorder in which the accumulation of cholesteryl esters and triglycerides predominantly in hepatocytes and cells of the macrophage-monocyte system is observed. The disturbance in the synthesis and trafficking of cholesterol and other lipids (triglycerides as well as phospholipids) as well as the systemic lipoprotein dysregulation, reflects the pathophysiology of LAL-D. The aim of this study was to present the occurrence of macrophage derived structures in LAL-D patient, and to provide an overview on underlying mechanisms, as the literature about the presence of such cluster cells in LAL deficiency is sparse. We describe the case of LAL-D patient diagnosed at 3 years of age, in whom the massive macrophage accumulation resulting in the abdominal lymphadenopathy, subcutaneous papules and hepatosplenomegaly, have been observed within 4 years since diagnosis. Histopathological examination of the excised lymph nodes and subcutaneous papules revealed them to be diffusely infiltrated by lipid-overloaded histiocytes. The immunohistochemistry revealed the macrophages to be CD68-positive. This study comprises one of the first reports of accumulation of lipid-laden macrophages throughout the body in the course of LAL-D.