Histiocytosis X or Langerhans' cell histiocytosis - Evaluation, treatment and prognosis

Objectives: The pathology and the extreme clinical varieties of th is disease with em ph asis on head and neck manifestations are discussed. Material: A case of Langerhans' cell histiocytosis (LCH) with extensive destruction of temporal bones is presented. Results and Conclusions: LCH or histiocytosis X embraces a group of rare, mainly pediatric disorders of disputable nature. Granulomatous lesions can be detected in one (unifocal) or multiple organs or tissues (multifocal) with extreme clinical variety from self-healing monostotic lesions to multisystemic life-threatening disease. Lesions typically consist of dendritic antigen-presenting Langerhans' cells, eosinophilic granulocytes, lymphocytes, ordinary histiocytes, foam cells and multinucleated giant cells. No histopathologic criteria exist in regard to prognosis. Unpredictable behavior of LCH also defies a convenient clinical classification, but number of lesions, vital organ involvement and dysfunction seem to be prognostically and thus therapeutically relevant. Although proof of monoclonality indicates a true neoplastic process, no prognostic use results so far since clonality has been detected in all forms of LCH.