Pigmented villonodular synovitis of thoracic facet joint presenting as rapidly progressive paraplegia.

Pigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovial membrane of uncertain etiology. It commonly affects synovial joints of the appendicular skeleton and rarely affects the spine. We present the case of a young man presenting with a rapidly progressive myelopathy due to spinal cord compression by PVNS arising from a thoracic facet joint, which finally resulted in paraplegia.The spinal location of PVNS has been seldom emphasized in the rheumatologic literature. PVNS should be considered as a possible cause of soft tissue masses arising from the facet joints, with variable degrees of nerve root or spinal cord compression.