Synovial chondromatosis in a facet joint of a cervical vertebra

Study design:A case report of a cervical facet joint synovial chondromatosis.

Objectives:To correlate the radiologic and histologic features of vertebral synovial chondromatosis with review of the literature.

Summary of background data:Only two previous cases of vertebral facet joint synovial chondromatosis were found in a review of the English language medical literature.

Methods:A 39-year-old woman had severe cervical pain associated with neurologic signs and symptoms in the left upper extremity. Computed tomographic and magnetic resonance imaging studies were performed.

Results:Imaging studies showed lytic defects in the laminae of C3 and C4, with intermediate T1 and high T2 signal intensities. The diagnostic impression was that of a lymphangioma or synovial cyst. A laminectomy showed synovial tissue in both the C3-C4 facet joint and the lamina bone. Histologic examination disclosed synovial chondromatosis.

Conclusions:Synovial chondromatosis of the vertebral spine is quite rare, this being only the third reported example. Direct invasion of the cancellous bone, as in this case, also is a very uncommon feature of chondromatosis. It is emphasized that when radiologic studies demonstrate a lesion with cartilaginous characteristics within or juxtaposed to a joint, synovial chondromatosis, despite its rarity, should be included in the differential diagnosis, regardless of the anatomic site.