[Chronic gait disorder caused by pigmented villonodular synovitis of the sole of the foot].

A 13 year old girl showed increasingly over one and a half year a gait disturbance suspected to be a progressive neurologic disorder. Laboratory tests and routine x-rays were normal. Soft tissue radiography finally demonstrated a dense area on the sole of the left foot which was excised and identified as a pigmented villonodular synovitis (PVNS). The girl is well now. Because PVNS is a rare disorder in childhood the diagnosis is seldom suspected and difficult; however, it should be considered as a cause for localised pain and its consequences.