Pigmented villonodular synovitis of the foot and ankle: a review of six cases.

Pigmented villonodular synovitis is a rare but well recognized proliferative lesion of synovial tissue. It has been most commonly described in the knee and hip, with most series reporting <5% occurrence in the foot and ankle. Six patients with pigmented villonodular synovitis of the foot and ankle that was treated between 1978 and 1997 were reviewed. Four of the patients had not been previously diagnosed, and two patients presented with recurrent disease. All six were women. Two patients' disease presented isolated to the ankle joint. The other four involved more than one joint: subtalar joint and midfoot in two, and the metatarsal region in two. The histology of the primary and recurrent lesions did not differ. The recurrent lesions were more diffuse and locally destructive. Five were found on magnetic resonance imaging to be a low-to-medium signal intensity mass on T1- and T2-weighted images. Surgical management ranged from simple excision to synovectomy to Lisfranc amputation. Average follow-up was 13 months (range, 3 weeks to 51 months). One of the lesions recurred 4 years later.