Langerhans cell histiocytosis: presentation and evolution of radiologic findings with clinical correlation.

Radiologic images and medical records of 42 children with Langerhans cell histiocytosis (LCH) (histiocytosis X) were reviewed to evaluate the presentation of the disease and the evolution of the radiologic findings. There were 26 male and 16 female patients aged 3 months to 18 years. Twenty-two patients presented with localized disease; 20 presented with multifocal disease. Four patients developed diabetes insipidus. Two patients had organ dysfunction. The radiologic findings were largely due to destructive bone lesions; 83% of the patients had at least one affected bone. Isolated soft-tissue masses, interstitial lung disease, and central nervous system abnormalities were also seen. Of patients in whom results of appropriate follow-up were available, 91% showed improvement in their lesions, 43% developed new lesions, and 92% had good clinical outcomes. LCH is usually a self-limited disease with a varied clinical and radiologic presentation. The prognosis is generally poor in children with organ dysfunction. In the absence of organ dysfunction, children with either localized or multifocal LCH have an excellent prognosis.