Synovial hemangioma of the knee joint with cystic invasion of the femur: a case report and review of the literature.

Synovial hemangioma is a rare benign intra-articular tumor. It may be a cause of pain and recurrent joint swelling in children and young adults. This report presents a 29-year-old patient with a synovial hemangioma in the left knee joint. Magnetic resonance imaging (MRI) showed the typical features of a soft tissue hemangioma and revealed a cystic invasion of the medial femur. The tumor was locally excised and a partial synovectomy was performed. The lesion of the femur was filled with autologous bone from the iliac crest. Histological examination confirmed the diagnosis of a synovial hemangioma. In a review of the recent literature we report the common features of a synovial hemangioma, with emphasis on its diagnosis and therapy.