LANGERHANS CELL HISTIOCYTOSIS IN IDENTICA L TWIN SISTERS

Background. - Histiocytosis of Langerhands cells includes a range of c linical manifestations that have been described as bone eosinophilic g ranuloma, Hand-Schiller-Christian syndrome, Letterer-Siwe syndrome and Hashimoto-Pritzker histiocytosis. These syndromes represent a spectru m of severity and prognosis of the same underlying disorder which is u sually sporadic. It has occurred in monozygotic twins and in a familia l pattern. This report describes monozygotic twins who developed the d isease a few months after their family was found to be suffering from Hodgkin's disease. Case n degrees 1. - A 4 month-old girl was admitted because of fever, disseminated lymphadenopathy and hepatomegaly. She also had interstitial pneumonia. Infiltrating abnormal histiocytes wer e demonstrated in lymph node and bone marrow biopsies. X-rays showed l ytic areas in the skull. Serology for EBV infection was negative. Spec ial studies with immune markers of lymph node histiocytes confirmed th e diagnosis of Langerhans cell histiocytosis, and more precisely, Lett erer-Siwe syndrome. The patient was given prednisolone followed by vin blastine without success. She was given etoposide 11 weeks later, whic h induced remission. This treatment was replaced by vinblastine when t he patient was aged 2 years 9 months. Case n degrees 2. - The monozygo tic twin of the case n degrees 1 was also admitted at 4 months of age because of the same manifestations. Laboratory findings were identical to those of her sister, as was her response to the same drugs. The fa ther was diagnosed as having Hodgkin's disease 3 months before the fir st manifestation of Langerhans cell histiocytosis in his daughters. Hi s maternal uncle has also been treated for Hodgkin's disease. Immunolo gic studies of the twin were negative. Conclusion. - These cases of La ngerhans cell histiocytosis in monozygotic twins have no apparent rela tionship with the Hodkin's disease of their father. Etoposide seems to be useful for treating such severe forms of the disease.