Langerhans-cell histiocytosis

Langerhans-cell histiocytosis (LCH) is a disease of the monocyte-macrophage system. It has a diverse spectrum of clinical presentations and histological confirmation of the diagnosis is obligatory. Disease extent dictates therapeutic choices and therefore requires uniform patient assessment. Localized LCH (involvement of a single organ or system) has an excellent prognosis regardless of therapy mode, thus advocating a conservative approach. The course of multisystem LCH is variable and difficult to predict. Unfavorable prognostic factors are involvement of the liver, spleen and hematopoiesis. Systemic application of a combination of prednisolone and vinblastine is the current standard treatment of multisystem LCH and administration is divided into a more intensive initial phase and a less intensive continuation phase for a total duration of 1 year. Failure of standard therapy can be rescued by the more intensive combination of cladribine and cytarabine or by allogeneic stem cell transplantation but these options can be delivered only in centers with corresponding expertise and adequate supportive care.