Foam cells seen in -

Niemann-Pick DiseaseThis is also an autosomal recessive disorder characterized by the accumulation of sphingomyelin and cholesterol due to a defect in acid sphingomyelinase.Two types have been described: type A and B.Type A is more common and typically presents in infancy and is characterized by hepatosplenomegaly, lymphadenopathy, rapidly progressive deterioration of CNS and physical underdevelopment. About a quaer of patients present with familial amaurotic idiocy with characteristiccherry-red spots in the macula of the retina (amaurosis = loss of vision without apparent lesion of the eye).Type B develops later and has progressive hepatosplenomegaly with development of cirrhosis due toreplacement of the liver by foam cells, and impaired lung function due to infiltration in lung alveoli.Microscopy shows storage of sphingomyelin and cholesterol within the lysosomes, paicularly in the cells of the mononuclear phagocyte system. The cells of Niemann-Pick disease are somewhat smaller than Gaucher cellsand their cytoplasm is not wrinkled but is instead foamy. These cells are widely distributed in thespleen, liver, lymph nodes, bone marrow, lungs, bowel, and brain. Ref: Harsh Mohan - Textbook of Pathology, 6th Edition.page no.263