Atypical spine involvement of Erdheim-Chester disease in an elderly male.

Erdheim-Chester disease is a rare form of non-Langerhans histiocytosis presenting in the 5th through 7th decades of life. Osseous manifestations include symmetrical sclerosis of the long bones and, rarely, the spine. Central nervous system disease commonly affects the white matter tracts as well as the orbits, but epidural disease is rare. To the best of the authors' knowledge, simultaneous epidural and skeletal spine disease has not been reported. The MR imaging characteristics of skeletal spine disease have also not been reported. The authors describe the case of an 87-year-old man with both epidural and skeletal spine disease. The clinical characteristics, imaging manifestations, and the histological features are discussed.