Pigmented villonodular synovitis of a lumbar intervertebral facet joint

Background contextPigmented villonodular synovitis (PVNS) is a slowly progressive lesion of uncertain etiology that involves the synovial membrane of joints or tendon sheaths. Only rarely does PVNS affect the axial skeleton, where it arises from the vertebral articular facet joint. Its treatment and prognosis remains limited.PurposeTo describe our management in a patient with PVNS and to review previously published cases.Study designCase report.MethodsThis is a case report of a 59-year-old woman who presented left sciatica. Computed tomography (CT) imaging revealed a mixed sclerotic and lucent lesion affecting the left L4–L5 facet joint. Magnetic resonance imaging (MRI) demonstrated a diffusely infiltrative process that originated from the left inferior articular process of L4 vertebra with extension into the spinal canal. A total synovectomy with left L4 hemilaminectomy was performed. Left L5 root was decompressed with total microscopic tumor removal. Decompression of spinal canal and absence of the tumor was shown by MRI and CT scan after the operation.ResultsComplete resolution of the patient's complaints was achieved. Histopathological analysis was consistent with a diagnosis of PVNS.ConclusionsThe principle of surgical management of spinal lesions causing neurologic deficit is early surgical decompression. It is also important to totally remove the synovium, the origin of PVNS, to prevent the recurrence.