Langerhans Cell Histiocytosis OMIM

Description: The Langerhans cell is a dendritic cell of the epidermis that was first described by a medical student, Paul Langerhans, who thought it was part of the nervous system (Langerhans, 1868). Birbeck et al. (1961) found that the Langerhans cell displays a unique electron-microscopic morphology. The discoveries that these cells are not confined to skin and that they make up a sizable portion of the cellular infiltrate in histiocytosis X (246400), along with other evidence, suggested that they play an immunologic role in protecting against environmental antigens. Egeler and D'Angio (1995) presented a classification of histiocytosis syndromes in children: class I, Langerhans cell histiocytosis (LCH); class II, histiocytosis of mononuclear macrophages other than Langerhans cells, including familial hemophagocytic lymphohistiocytosis (267700); and class III, malignant histiocytic disorders, including histiocytic lymphoma.