Langerhans’ Caenldl histiocytosis: case reports literature review

L angerhans’ cell histiocytosis (LCH), formerly known as histiocytosis X, is one of a group of poorly understood diseases of histiocytes. The clinical spectrum of disease ranges from the chronic, localized form to an acute leukemia-like disease with a fatal outcome. Alfred Hand was the first to report a case of histiocytosis in 1893.1 Later, in 1941, Farber described this condition when reporting the overlap among diseases that would later be termed histiocytosis X.2,3 Since that time, numerous case reports have appeared in the dental literature, each having a diverse focus and using inconsistent terminology. The purpose of this review article is to enhance the understanding of LCH and to report two cases of very young children demonstrating skull and jaw lesions. LCH previously has been considered a reactive polyclonal disease of immune regulation and not a true neoplasm. More recent evidence, however, has demonstrated clonal proliferation, a key neoplastic feature. 4-6