Presentation
Right knee swelling and functional limitation.
Patient Data
Modest joint effusion with numerous synovial nodules characterized by enhancement and hemosiderin deposits (blooming artifact on GRE), mainly located in the suprapatellar recess and in the intercondylar notch.
Bone lesions are not appreciable.
Surface erosion of the articular cartilage of the medial facet of the patella.
Normal menisci, and cruciate and collateral ligaments.
Case Discussion
Villonodular pigment synovitis (PVNS) is a proliferative type of synovial membrane that most commonly affects the knee joint. It is classified as a tumor with local malignancy because the proliferation of synovial and histiocytic cells leads to an accumulation and deposition of hemosiderin and cholesterol, causing osteolytic degeneration of the articular components that can sometimes invade the surrounding soft tissues.