Adult Niemann-Pick disease: its relationship to the syndrome of the sea-blue histiocyte.

Three unrelated female patients with adult Niemann-Pick disease are described. All the patients had reduced coagulation factors and involvement of the marrow, liver, spleen and lungs. Two patients were shown to have abnormal platelet function; two patients also had pingueculas and a late onset of a menarche. Foam cells and sea-blue histiocytes were seen in the marrow and livers in all three patients, in the spleen in two patients in the lymph nodes in one patient. The clinical presentation, the histologic appearance, the histochemical staining reactions, the lipid analysis and the ultrastructure were all consistent with a diagnosis of adult Niemann-Pick disease. On the basis of these observations, it is clear that adult Niemann-Pick disease is a cause of the syndrome of the sea-blue histiocyte. The existence of the syndrome of the sea-blue histiocyte as a separate entity is also questioned.