Langerhans cell histiocytosis in adults. Report of 2 cases

Abstract

Langerhans cell histiocytosis (LCH) is a myeloid neoplasm of dendritic cells (DC), characterized by the clonal expansion of myeloid precursors that express the surface antigens CD1a+ and CD207+. LCH is a rare and infrequent disease, of predominantly pediatric onset with an annual incidence ranging between 2 and 9 cases per million, being even rarer in adults, with an estimated annual incidence of approximately 1 case per million, although this value probably reduced is due to an underdiagnosed disease in this population. The clinical course is heterogeneous, it can present from an indolent self-limited lesion (solitary eosinophilic granuloma) to a disseminated disease with rapidly progressive organ dysfunction, which can lead to death. The Histiocyte Society (HS) classifies the clinical forms of LCH according to the number and type of organs affected: single system LCH (SSLCH) if one organ/system is affected (either unifocal or multifocal) and multisystem LCH (MS- LCH) if two or more organ systems are involved. We will present two cases of HCL, one with involvement of a SS and another MS.