[Langerhans-cell histiocytosis in twin sisters]

BACKGROUND--Histiocytosis of Langerhans cells includes a range of clinical manifestations that have been described as bone eosinophilic granuloma, Hand-Schüller-Christian syndrome, Letterer-Siwe syndrome and Hashimoto-Pritzker histiocytosis. These syndromes represent a spectrum of severity and prognosis of the same underlying disorder which is usually sporadic. It has occurred in monozygotic twins and in a familial pattern. This report describes monozygotic twins who developed the disease a few months after their father was found to be suffering from Hodgkin's disease. Case n. 1.--A 4 month-old girl was admitted because of fever, disseminated lymphadenopathy and hepatomegaly. She also had interstitial pneumonia. Infiltrating abnormal histiocytes were demonstrated in lymph node and bone marrow biopsies. X-rays showed lytic areas in the skull. Serology for EBV infection was negative. Special studies with immune markers of lymph node histiocytes confirmed the diagnosis of Langerhans cell histiocytosis, and more precisely, Letterer-Siwe syndrome. The patient was given prednisolone followed by vinblastine without success. She was given etoposide 11 weeks later, which induced remission. This treatment was replaced by vinblastine when the patient was aged 2 years 9 months. Case n. 2.--The monozygotic twin of the case n. 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 father was diagnosed as having Hodgkin's disease 3 months before the first manifestation of Langerhans cell histiocytosis in his daughters. His maternal uncle had also been treated for Hodgkin's disease. Immunologic studies of the twin were negative. CONCLUSION--These cases of Langerhans cell histiocytosis in monozygotic twins have no apparent relationship with the Hodgkin's disease of their father. Etoposide seems to be useful for treating such severe forms of the disease.