A Unique Case of Erdheim-Chester Disease With Cervical and Lumbosacral Nerve Involvement: FDG PET/CT Finding.

Cervical and lumbosacral nerve roots and plexus involvement in Erdheim-Chester disease (ECD) is rare. A 50-year-old man with progressive edema in bilateral lower extremities, numbness, weakness, and muscle atrophy of upper limb for 2 years had been misdiagnosed of neuritis or cervical spondylosis until he presented bone pain. In addition to bilateral symmetric involvement in long bones, bilateral hypermetabolism in cervical and lumbosacral nerve roots was found by FDG PET/CT scan. ECD was diagnosed by bone biopsy. This case reported the rare peripheral neural involvement and highlighted the advantage of FDG PET/CT scan in evaluating the multisystem involvement of ECD.