Niemann-Pick diseases are genetic diseases primarily due to deficiency of sphingomyelinase resulting in the accumulation of sphingomyelin within lysosomes in the macrophage-monocyte phagocyte system, mainly the brain, spleen, liver, lung, and bone marrow. Histology demonstrates lipid laden macrophages in the marrow, as well as "sea-blue histiocytes" on pathology. The infantile form with a dominant neurologic expression is rapidly fatal. In older patients, cases of ILD have been reported [131] .