Synovial Haemangioma of the Elbow: A rare paediatric case and imaging dilemma.

Synovial haemangiomas are rare benign vascular proliferations arising in synovium-lined surfaces. While the knee is by far the joint most commonly involved, this condition can also occur in the elbow. We report an eight-year-old boy who presented to the National University of Malaysia Medical Centre, Kuala Lumpur, Malaysia, in 2016 with a left elbow swelling of one year's duration. Magnetic resonance imaging showed a lobulated intra-articular mass with intermediate signal intensity on T1-weighted imaging and low signal punctate and linear structures within the hyperintense mass on T2-weighted imaging. In addition, there was heterogeneous yet avid contrast enhancement on post-gadolinium contrast images. The mass had juxta-articular extension and bony erosion to the coronoid process and the head of the radius. Synovial haemangiomas present a diagnostic dilemma. This report highlights certain imaging characteristics to distinguish this entity from other differential diagnoses.