Pigmented villonodular synovitis (PVNS) refers to a group of benign tumors originating from the synovial lining of joints or tendon sheaths. It can occur around a joint or within the tendon sheath, with the latter being called giant cell tumor of the tendon sheath. When occurring in joints, PVNS can be classified into villous and nodular types.
Clinical Features
PVNS is most commonly seen in individuals aged 20 to 40 years and frequently affects the knee and hip joints. The primary symptoms include joint swelling and mild pain, and in some cases, the local skin temperature may be slightly elevated. Mild restrictions in joint movement may also be observed. Upon physical examination, swollen joints with tenderness can be palpated, and the synovium may feel spongy. Joint effusion tests are typically positive. The lesion may erode bone or involve the tendon sheaths, with the flexor tendon sheath of the hand being relatively common. This often presents as solitary, firm, rubbery nodules. Joint aspiration may yield bloody or yellow-brown fluid.
Treatment
The primary treatment involves surgical removal of the tumor mass or affected synovium. However, due to the diffuse nature of the lesion, complete resection may be challenging, increasing the likelihood of recurrence. When complete resection is not feasible, postoperative radiotherapy is recommended to reduce the risk of recurrence.