Magnetic Resonance Imaging (MRI) Findings in a Case of Pigmented Villonodular Synovitis of the Knee.

Pigmented villonodular synovitis (PVNS) is a rare benign condition of tenosynovial proliferation that mostly affects the knee joint. In this case report, we present a 39-year-old female with a ten-year history of gradual progression in the size of painful soft tissue swelling in her left knee. Our case report emphasizes the MRI's ability to provide detailed information on tendon sheath and synovium involvement, as well as extensive extra-articular involvement and hemosiderin deposition.