• ABSTRACT
    • Fourteen cases of pigmented villonodular synovitis (PVNS) of the foot and ankle accrued from the Scottish Bone Tumor Registry are presented with an average follow-up of 4.6 years. This study analyzed the clinical, radiological, and histopathological features and investigated their clinical behavior and the factors influencing recurrence. The mean age of the patients was 26.4 years (range, 8-52 years). There were 8 women and 6 men. The mean delay in presentation was 10.3 months. The anatomical sites were phalanges (n = 2), tarso-metatarsal area (n = 3), and hindfoot (n = 9) (6 extraarticular soft tissue swellings around the ankle, 2 ankle, 1 subtalar joint). Eight (57.1%) cases presented with a painless lump, 5 (35.7%) patients had painful masses, and 1 case had a lump associated with toe deformity. Peri-articular tissue invasion and cortical infiltration were found in one third on plain films. Magnetic resonance imaging findings were suggestive of synovial sarcoma in 2 cases because of extensive low-signal soft tissue hypertrophy and bone erosion. Excision of the lump was performed in 4 cases with a complete recovery. Phalangeal lesions were treated with toe amputation through the metatarsophalangeal joint, and no cases had recurrence. There were 2 recurrences affecting the ankle and the subtalar joint. There was a 14.3% recurrence rate, while complete recovery was achieved in 85.7% cases (12/14). A high index of suspicion for PVNS should be observed for cases presenting with a painless or painful mass in the foot and ankle region. Complete recovery can be achieved in the majority by complete excision. Toe amputation may be considered for foot phalangeal PVNS.