Sea‐Blue Histiocytes in Familial Lecithin: Cholesterol Acyltransferase Deficiency

Histiocytes containing large blue‐green granules on Wright or Giemsa stain have been described in several different clinical conditions, some of them with hepatosplenomegaly and thrombocytopenia. These conditions have been ill‐defined with no common characteristics. In the present report evidence is given for the presence of ‘sea‐blue histiocytes’ in all five patients with familial lecithin: cholesterol acyltransferase deficiency examined. From electron microscopic studies it is suggested that the characteristic cytological appearance of the histiocytes in the spleen and bone marrow in these patients may be due to increased phagocytosis and decomposition of blood cells, or more probably to uptake of phospholipid‐containing membraneous material directly from plasma.