Acquired lipidosis of marrow macrophages: birefringent blue crystals and Gaucher-like cells, sea-blue histiocytes, and grey-green crystals.

Three varieties of compound lipid inclusions occurring as a secondary phenomenon in marrow macrophages are detectable and distinguishable by Romanowsky staining, ultraviolet fluorescence, and polarised light. Birefringent blue crystals and Gaucher-like cells form one variety, sea-blue granules another, and grey-green crystals a third. All occur chiefly in myeloid leukaemias, either acute or chronic.