SYNOVIAL HEMANGIOMA OF THE KNEE - A FREQUENTLY MISDIAGNOSED LESION

Objective. The objective of this study was to assess the contribution of magnetic resonance (MR) imaging in the diagnosis and surgical plann ing of five cases of synovial haemangioma of the knee. Patients and me thods. The clinical, radiological and arthroscopic features of five pa thologically proven synovial haemangiomas of the knee were retrospecti vely reviewed. Results. A diagnostic delay, on average of 8 years, had occurred in four of the cases. Plain films were unremarkable, except for one case with arthropathy mimicking haemophilia, Arteriography, pe rformed in three patients, was normal in one. CT, performed in three p atients, showed the lesion, but the extent of the latter was better de monstrated with MR imaging. Synovial haemangiomas had a high signal in tensity on T2-weighted images, without any extensive mass effect. Fibr ofatty septa within the lesion were observed in three cases and muscul ar and/or fatty invasion in two. Arthroscopy allowed diagnosis of the lesion in two cases, but showed only nonspecific synovitis in another two. Conclusion. This study emphasizes the valuable contribution of MR imaging in the diagnosis and surgical planning of synovial haemangiom as.