THE RELATION OF LANGERHANS CELL HISTIOCYTOSIS TO ACUTE-LEUKEMIA, LYMPHOMAS, AND OTHER SOLID TUMORS - THE LCH-MALIGNANCY STUDY-GROUP OF THE HISTIOCYTE-SOCIETY

The frequency of Langerhans cell histiocytosis (LCH) and a malignant n eoplasm occurring in the same individual appears to be greater than pr eviously recognized. To define the occurrence and the pattern of these events, a Study Group of the Histiocyte Society initiated a registry of patients in whom this association occurred synchronously or asynchr onously. Evaluation of 54 patients detected two patterns of associatio ns between LCH and other disorders. First, it is possible that therapy of LCH promotes a secondary malignancy. Second, it is possible that a genetic predisposition, with or without the immunosuppression associa ted therapy for the malignancy, plays a role in the development and ex pression of disseminated LCH. Data collected by the LCH Malignancy Stu dy Group may provide insights into the etiology and pathophysiology of LCH.