Pigmented villonodular synovitis of the spine: a clinical, radiological, and morphological study of 12 cases.

Cases of pigmented villonodular synovitis (PVNS) that affect the axial skeleton are rare and thus information regarding its natural history, treatment, and prognosis remains limited. To characterize this lesion more fully, the authors reviewed their experience with 12 cases of PVNS of the spine (one of which had been previously reported), then reviewed the 11 cases that previously had been reported, and obtained additional follow-up data in six of them. On the basis of the cumulative data provided by these 22 cases, PVNS of the spine appears to occur over a wide range of ages (21-81 years) and, contrary to what was previously suggested, does not show definite gender predilection (12 women and 10 men). The lesion affects the posterior elements of the vertebrae at all levels and involves the facet joints in 89% of cases. Extension into the epidural spine is frequent (70%). Surgical resection appears to be the treatment of choice. Although PVNS of the spine tends to recur locally (18%), repeat surgical excision appears to be curative.