Undiagnosed Intra-articular Synovial Hemangioma: A Rare Cause of Knee Pain and Swelling.

As radiography has limited diagnostic ability, synovial hemangiomas are difficult and challenging to identify on an outpatient basis. Histological examination and magnetic resonance imaging are extremely helpful. To minimize the hemarthrosis risks, early complete excision can be used as the best treatment modality.