Synovial haemangioma 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 planning of five cases of synovial haemangioma of the knee.

PATIENTS AND METHODS

The clinical, radiological and arthroscopic features of five pathologically proven synovial haemangiomas of the knee were retrospectively 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, performed in three patients, was normal in one. CT, performed in three patients, showed the lesion, but the extent of the latter was better demonstrated with MR imaging. Synovial haemangiomas had a high signal intensity of T2-weighted images, without any extensive mass effect. Fibrofatty septa within the lesion were observed in three cases and muscular 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 haemangiomas.