[Congenital Letterer-Siwe disease].

Observations of congenital Letterer-Siwe disease in girls of 15 and 10 months are presented. In both infants the skin, lungs, lymph nodes, and spleen were involved; besides, one of them had the liver affected, the other the bones. Both girls had cachexia, pancytopenia. One infant received hormone and chemotherapy for 1 1/2 months, the other was given no specific treatment. Microscopic examinations of the affected organs revealed focal-diffuse outgrowth of cells of the histiocyte type with disorders in the normal structure of the organs. Electron microscopic examinations of foci of lesions in the lungs and of the affected lymph node demonstrated two predominant types of proliferating cells: differentiated histiocytes and moderately differentiated histiocytes.