Pigmented Villonodular Synovitis of the Ankle—Radiation Therapy as a Primary Treatment to Reduce Recurrence: A Case Report with 8-year Follow-up

Pigmented villonodular synovitis (PVNS) is a rare, benign, idiopathic proliferative disorder of the synovium that results in villous and or nodular formations that have been reported to manifest within joints, tendon sheaths, and bursae. The overall incidence includes 2% to 10% that occur within the foot and ankle joints. PVNS has a high rate of recurrence and up to a 45% recurrence rate has been reported despite surgical intervention. Although traditional treatment for PVNS includes synovectomy with arthroplasty of the affected joint, radiation therapy is now suggested as an adjunctive therapy that is believed to reduce recurrence of the disease. We present a case of PVNS where the patient was treated in 2 stages: surgical resection of the tumor with arthroplasty of the ankle joint followed by radiation therapy. A retrospective review of the chart, radiographs, and MRIs was conducted for a 36-year-old, African American female who had been treated and followed for 8 years. Pathologic examination of the tumor confirmed the diagnosis of PVNS. No evidence of recurrent PVNS was identified in the long-term postoperative MRI examination. The fact that ancillary imaging examinations failed to reveal evidence of recurrence and that the patient expresses a very high patient satisfaction supports the potential benefit of adjunctive radiation therapy for this condition.