Joint tumors

[Tariq Zaki]

Tumors rarely affect joints unless a bone tumor or soft-tissue tumor is near a joint. However, two conditions—synovial chondromatosis and pigmented villonodular synovitis—occur in the lining (synovium) of joints. These tumors are noncancerous (benign) but can cause severe damage to the joint. Both conditions usually affect one joint, most often the knee or the hip, and can cause pain and a buildup of fluid.
To diagnose these conditions, doctors do x-rays, computed tomography (CT), magnetic resonance imaging (MRI), or a combination. To confirm the diagnosis, doctors usually remove a tissue sample for examination under a microscope (biopsy).
Treatment for both requires surgical removal of the abnormal synovium (called synovectomy).
(See also Overview of Bone Tumors.)