[Sea-blue histiocytes and Gaucher-like cells. Occurrence and significance]

Sea-blue histiocytes (SBH) and Gaucher-like cells are macrophages containing a pigment related to or identical with ceroid or lipofuscin. While an occasional cell may be found in the normal bone marrow, large numbers of SBH can be observed in various conditions mainly associated with increased cellular breakdown or with disturbances of lipoid metabolism. We have examined smears and/or sections of bone marrow and spleens of 722 patients with various hematological disorders. In only four instances large numbers of SBH could be found, twice in the bone marrow, once in the spleen and once in both organs. Two of these patients were suffering from immune thrombocytopenia. Gaucher-like cells have a different morphologic appearance although the pigment shows the same cytochemical characteristics as in SBH. Gaucher-like cells are mainly found in patients with chronic myeloid leukaemia and are thought to be related to the increased breakdown of granulocytes. The exact mechanisms responsible for the formation of these pigment macrophages are not yet known. In the author's view it does not seem justifiable to speak of a special "syndrome of the blue macrophages".