Treatment for Langerhans Cell Histiocytosis of Single System Disease

Abstract

Langerhans cell histiocytosis (LCH), a most common histiocytic disease, consists of single-system disease (affecting only one organ/system) or multi-system (with involvement of two or more organs/systems). The incidence ratio of single-system to multi-system disease is about 2 to 1. The single system disease occurs, as either single or multiple lesions, in the bones, skin, lymph nodes or lungs, but the majority (90%) is found in the bones. Currently, the multi-focal single system disease is a candidate for systemic chemotherapeutic treatment, where it isessential to increase the cure rate by reducing the high incidence of reactivation and permanent sequelae, such as diabetes insipidus (DI), central nervous system dysfunction and orthopedic disabilities. Regardless of systemic chemotherapy, the patients with multi-focal bone disease are known to inter reactivation of about 40% and DI of about 10%during the treatment. In particular, care must be taken for patients with craniofacial bone lesions, both for single and multi-focal diseases, because of the high incidence of DI and/or neurological sequelae. In this review, we overview the various issues in relation to the treatment of single-system LCH.