Localized pigmented villonodular synovitis
Knee pain without trauma. Incidental finding.
Loading Stack -
0 images remaining
MRI Left Knee without and with contrast
In the popliteal fossa, laterally, at the posterior surface of the femoral condyle in the gradient echo T2 sequences, is visible oval formation with blooming artifact caused by magnetic susceptibility from intracellular hemosiderin deposits.
This lesion, at regular margins, erodes the cortical plane of the femoral condyle and shows discrete enhancement after contrast.
Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferative disease of the synovial membrane of joints, tendon sheaths, and bursas.
It presents in two forms: diffuse and localized.
The localized form is usually a single pedunculated mass or, less frequently, two or three nodules.
Histologically there is active proliferation of fibroblastic and histiocytic elements, showing macrophagic activity with phagocytosis of blood pigment (hemosiderin) and lipids.