Accumulation of sphingomyelin in spleen and liver is found in:

Niemann-Pick diseases are genetic diseases which are classified in a subgroup of LSDs called sphingolipidoses or lipid storage disorders in which harmful quantities of fatty substances, or lipids, accumulate in the spleen, liver, lungs, bone marrow, and brain.In the classic infantile type A variant, a missense mutation causes complete deficiency of sphingomyelinase. Sphingomyelin is a component of cell membrane including the organellar membrane and so the enzyme deficiency blocks degradation of lipid, resulting in the accumulation of sphingomyelin within lysosomes in the macrophage-monocyte phagocyte lineage.Histology demonstrates lipid laden macrophages in the marrow, as well as "sea-blue histiocytes" on pathology.