Aggressive and atypical manifestations of Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a disseminated non-Langerhans' cell histiocytosis with multisystem involvement, including characteristic sclerotic musculoskeletal lesions. We present the case of a 27-year-old woman with a fulminant course and atypical involvement by ECD manifesting as extensive cerebrovascular disease and lytic musculoskeletal lesions. This case represents an unusual and aggressive presentation of ECD owing to the patient's young age, the severity of the cerebrovascular involvement and the lytic osseous lesions.