[Synovial Haemangioma of the Knee - Diagnosis by Magnetic Resonance Imaging].

Synovial hemangioma is a rare nonneoplastic vascular malformation of the synovial membrane described by Bouchut in 1856. Fewer than 200 cases have been described in the literature, corresponding to 1% of all hemangiomas. The presenting symptoms are often non-specific, which often leads to a delay in diagnosis of many years and can result in arthropathy if left undetected. The early diagnosis of a synovial haemangioma is important as recurrent haemarthrosis may lead to irreversible joint damage and chronic inflammatory synovitis. In practice, there is no consensus on the best treatment of synovial hemangiomas in children. Total resection of the tumor can be performed by arthroscopy in localized forms and for small lesions. Open resection associated with synovectomy is necessary when the hemangioma occupies most of synovial membrane.