Diffuse tenosynovial giant cell tumor, also referred to as pigmented villonodular synovitis, is a rare, benign growth in the synovial lining, tendon sheaths, and bursae of joints. It usually occurs at the knee but can also affect the hip, ankle, foot, and other sites. It is most often diagnosed in patients aged 30-50 years. There is a female predominance.

Signs and symptoms include progressive pain or discomfort, swelling, redness, tenderness, stiffness, limited range of motion, and palpable mass.

First-line management is for treatment of symptoms. Other treatments are open surgical synovectomy, arthroscopic surgical synovectomy, radiotherapy, arthrodesis, and arthroplasty.

Related topic: Giant Cell Tumor of Tendon Sheath