[Synovial hemangioma of the knee joint]

The making of the diagnosis and the histological morphology of the synovial capillary hemangioma of the knee joints is discussed. The cause of this rare condition which is accompanied by monarticular or oligarticular swellings and increased linear growth of an extremity, is a benign tumor-like change of the synovial vessels. It affects the capillary and/or the venous systems and occurs mainly in children and adolescents. The treatment of choice is an early as possible radical synovectomy. Two cases diagnosed late are reported. One of them was diagnosed 17 years after onset of symptoms, despite two previous arthrotomies. It resulted in severe joint destruction. According to what the morphological appearance is, radical early synovectomy, irradiation treatment or steroid treatment is the most appropriate therapy.