Imaging of extraosseous intracranial and intraspinal multiple myeloma, including central nervous system involvement.

Involvement of the central nervous system by multiple myeloma is rare and has a very poor prognosis. Magnetic resonance imaging of the head and spine plays an important role in diagnosing central nervous system involvement with multiple myeloma. We retrospectively analyzed the imaging features of pathology-proven extraosseous intracranial and intraspinal multiple myeloma from 2002 to 2013. The most common imaging manifestations were extraaxial nonosseous spinal lesions, cranial nerve involvement, and intracranial extraaxial nonosseous lesions. Different sites in the central nervous system may be affected by multiple myeloma, often simultaneously, producing a variety of imaging appearances.