Langerhans cell histiocytosis and the central nervous system in childhood:Evolution and prognostic factors. Results of a collaborative study

This retrospective study detailed clinical and radiologic involvement of th e central nervous system related to Langerhans cell histiocytosis in 18 Fre nch children. We excluded cases of isolated hypothalamic-pituitary dysfunct ion or spinal involvement. Cerebellar symptoms were the most common clinica l symptoms. Two different patterns of magnetic resonance or computed tomogr aphic images were identified: demyelination and gliosis or atrophy, describ ed as degenerative lesions, mostly located in the cerebellum in 10 children , or tumor-like lesions occurring in any Dart of the brain in 13 children. Six children had both types of lesion. The clinical cerebellar syndrome cor related will the specific imaging pattern suggestive of a cerebellar degene rative lesion, which did not show any changes after treatment. As suggested by this study and previous clinical and histologic reports, it is believed that brain involvement in the course of Langerhans cell histiocytosis migh t arise from different disease mechanisms: primary histiocyte proliferation and secondary atrophy or demyelination and gliosis of unknown origin. Trea tment consequently should be adapted to the supposed mechanism of the lesio n.