Letterer-Siwe disease in an octogenarian.

The case of an 81-year-old woman suffering for about 1 year from a typical form of Letterer-Siwe disease (LSD) is reported. The only important systemic involvement was hepatosplenomegaly. The patient was treated with steroids and vinblastine and then with thymopoietin pentapeptide. This last drug proved useful for decreasing the dose of steroid and thus for checking the appearance of new skin lesions. The ultrastructural investigations, carried out before and after vinblastine, showed the presence in some histiocytosis X cells (HXC) of coated Birbeck granules (BG). Immunoelectron microscopy showed about 90% of HXC to be OKT6+ and the OKT6 labeling of these cells to be similar to that of the Langerhans cells of normal skin. Five percent of OKT6+ cells apparently contained no Langerhans granules.