Sea-blue histiocyte disease is a clinical entity characterized by splenomegaly, mild purpura secondary to thrombocytopenia, and most often with a relatively prolonged benign course. Numerous sea-blue histiocytes are observed in many organs including the bone marrow, liver, and spleen. This disorder is classified as either primary or secondary; most cases are secondary to lipid metabolic diseases. A mutation in the APOE gene has been reported.
Most cases of sea-blue histiocytosis are secondary to lipid metabolic diseases, such as Niemann-Pick disease [DS:H00136], Fabry disease [DS:H00125], or ceroid strage diseases.
