PATHOMORPHOLOGY OF LYSOSOMAL STORAGE INCLUSIONS IN THE RETICULOENDOTHELIAL CELLS OF SPHINGOLIPIDOSES

Abstract

For the purpose of clarifying intralysosomal accumulation of intermediary catabolites in the reticuloendothelial cells of sphingolipidoses, 23 cases of Gaucher's disease, 7 of Fabry's disease, 2 of Sandhoff's disease, 4 of generalized gangliosidosis, 2 of Farber's disease and 11 of Niemann-Pick disease were studied histopathologically, histochemically or electron microscopically. In Gaucher cells characteristic of Gaucher's disease, the storage inclusions contained tubules of about 200 to 600A in diameter. In Fabry's disease, pleomorphic osmiophilic lamellated inclusions, which were histochemically of heterogenous nature, were stored, while Sandhoff's disease was characterized by accumulation of miniature but somewhat pleomorphic membranous cytoplasmic bodies in foam cells. As for generalized gangliosidosis, vacuolar inclusions similar to those seen in genetic mucopolysaccharidoses accumulated in the infantile type, but Gaucher-like cells predominated in the juvenile type, which contained fibrillar inclusions. In Farber's disease, curvilinear tubular structures were characteristic in the inclusions of foam cells. Myelin-like figures were found in the storage inclusions of Niemann-Pick cells. The variegated inclusions stored in the reticuloendothelial storage cells of these diseases were mostly surrounded by a delimiting membrane and enzyme cytochemically showed localization of acid phosphatase, indicating that they are transformed secondary lysosomes. Possible sources of the inclusions are discussed in most of the diseases.