Abstract
The histiocytosis represents the rare diseases with large biological behavior and clinical symptoms, as well. The Langerhans cell histiocytosis is the most frequent entities in children in this category.
The paper does the summary of the etiology, biology, clinical aspects, diagnostic possibilities, and therapeutic outcomes of LCH. The crucial prognostic value represents disease extension: single-system in compare with multi-system LCH.
The role of treatment in some LCH forms is questinable but in other forms the chemotherapy is important. Histiocytosis affects all age groups but more than 50% cases concern children up to 15 years of age.
There are not gender predominance but exist age dependent predisposition (e. g. bone disease in children 5-15 years of age or multi-system disease in children less than 2 years of age). Multi-system LCH incidence is aproximately 2.6 children/1 milion children/year (9 in chidren less to 1 year of age and 0.7 in age group 10-14 years).
In the Czech Republic supposed 10-20 children per year. Histiocytosis characterized abnormal accumulation mononuclear phagocytic cells (dendritic cells and macrophages) which are derivate from primary CD34+ hematopoietic stem cells.
The basic point in the differentiation process has large scope of cytokines. LCH was considered as malignant disease, reactive or aberrant immunological answer of organism in the previous time.
The last review showed disease with pathological Langerhans cells in granulomatous lesion together with common inflamantory elements as eosinophils, lymphocytes and macrophages. The cell infiltration and clinical symptoms are explained as outcome of aberant secretion these cells and activated T-lymphocytes.
Therefore clinical symptoms showed different type of manifestation from spontaneous regression through recurrent behavior to malignant multi-system disease with fatal outcome. Diagnosis is done by histopathological investigation with proof of intracellular Birbecks granules, imunohistochemical S-100 protein positivity, and CD1a+ as well.
But the Langerhans cell histiocytosis etiology and pathogenesis in unknown so far. The treatment strategy depends on the spread of disease.