Localized nodular synovitis of the ankle in children

A case of localized pigmented intra-articular nodular synovitis (NS) of the ankle in a child is described in the article. A 14-year-old girl presented with a painless mass along the posterolateral aspect of the right ankle. CT scan showed a nodular mass in the right posterolateral ankle joint. The histological study verified localized NS. This case confirms that localized NS is not frequent in the population of children.