Synovial hemangioma. Description of a case

Intra-articular angioma, or vascular hamartoma, is a tumor-like lesion essentially made up of anomalous blood vessels localized in the joint capsule, in the synovial membrane, or in both structures. There are two anatomical varieties: one circumscribed localized and one extended. There seems to be predilection for the female sex, and age of onset ranges from birth to 20-30 years of age; it occurs more frequently in the knee, less in the elbow, in the wrist and in the ankle. Symptoms, which often begin after local trauma, include joint swelling and pain, both characterized by discontinuity and long duration. Sometimes there is an increase in swelling, repeated episodes of hemarthrosis (or hydrarthrosis), forced position and functional limitation of the joint, increase in skin temperature. Final diagnosis can only be obtained with histological examination, although MRI may be useful and arteriography clearly reveals it, if the harmatoma is extended enough and communicating with the circulation. Histological examination carried out on fragments of tissue taken in loco reveals a labyrinthine agglomerate of fissures and lengthening cavities, with walls that are generally thick and of a venous-like anomalous type. The course of the disease is slow, with periods of remission of local symptoms of varying duration. Treatment is surgical and it consists in complete removal when possible of the angiomas. The results, particularly in the localized form, are satisfactory; recurrence is infrequent and it is generally due to incomplete excision of the neoformation.