Langerhans Cell Histiocytosis in childhood

Abstract

Histiocytoses are rare and heterogeneous group of disorders in childhood. The clinical presentation of Langerhans cell histiocytosis (LCH) is highly variable, from asymptomatic to clinically significant symptoms and consequences. As it can involve nearly every organ of the body, the clinical manifestations depend on the site of the lesions, on the organs and systems involved and whether their function is affected. The most common sites of involvement in LCH are bone, skin, lymph nodes, lung, bone marrow and hypothalamic-pituitary region. The classical presentation of LCH is a unifocal bone disease, previously known as eosinophilic granuloma. LCH can be divided according to disease extent: single- or multi-system disease. There is very high chance of spontaneous resolution and favourable outcome for single-system disease involving the skin or bone. In many cases, no therapy or only local therapy is enough. For patients with multi-system disease currently systemic therapy is the treatment of choice. The goal of treatment is to relieve clinical symptoms, to increase survival and prevent complications. Currently cooperative international trials of the Histiocyte Society are used for treatment of LCH based on a€˜risk group stratification' with therapeutic agents have generally paralleled those used for the treatment of malignancies. There is no standardized therapy for chronic relapsing, acute refractory and progressive disease, some alternative approaches have been tested. Childhood LCH is a well treatable disease and the survival rate is high. This article summarizes the classification, pathophysiology, diagnostic criteria, different clinical manifestations, treatment possibilities, prognosis and long-term sequelaes of LCH in children.