Localized pigmented villonodular synovitis of the vertebral column.

We studied two patients with paravertebral localized pigmented villonodular synovitis. This anatomic location has not, to our knowledge, been previously described as a site for lesions of this type. In one case, a cervical paravertebral lesion first appeared clinically as a hypopharyngeal mass. The other lesion was noticed incidentally by a roentgenogram and had eroded bone in the lumbosacral area of the spine. We believed both lesions to have arisen from synovial membranes of the accessory joints of the vertebral column.