Synovial hemangioma of the knee joint in a 3-year-old girl.

Synovial hemangioma has been reported to be relatively rare, and usually occurs in childhood and adolescence. However, there are a few reports of the disease in infants. In this report, we diagnosed synovial hemangioma in a 3-year-old girl who had swelling and pain in her left knee. Gadolinium-enhanced magnetic resonance imaging revealed abnormal intensity in an intra-articular lesion. We performed arthroscopy, and arrived at a final diagnosis based on a scopic biopsy. Synovial hemangioma should be considered as a possible diagnosis in infants with swelling and pain in the knee.