Spontaneous transient remission of disseminated histiocytosis X during pregnancy

Disseminated histiocytosis X with cutaneous and lymph node involvement was diagnosed in a 25-year-old women. The diagnosis was established on the basis of a positive cell-surface staining with OKT 6 and typical signs on electron microscopy. Both the specific skin rash and lymph node swelling completely disappeared during pregnancy, but recurred 2 weeks before delivery. Therapeutic trials with 0.25 mg ethinylestradiol/day and a later application of human chorionic gonadotropin up to 5000 IU i.m. twice weekly as well as prednisolone 25 mg three times per day were unsuccessful. A second pregnancy was not desired. Polychemotherapy with initial high-dose prednisolone plus vincristine and a consolidation therapy with 5-mercaptopurine 300 mg/day led to full recovery. The observation of transient remission of histiocytosis X during pregnancy suggests that at least some forms of this disease may have prevailing immunological features where an immunosuppressive effect of pregnancy could be beneficial.