|Text in Italics is general (instructional) information|
MRI - fats suppression study
At biopsy of the synovium which was brown with pigment, with a few giant cells present. This confirmed the diagnosis of Pigmented Villonodular Synovitis.
Differential diagnosis of hypertrophied pigmented synovium
Histologically the giant cell tumor of tendon sheath can be similar, but is usually only a small nodule. On Magnetic Resonance Lipoma arborens can give a similar hypertrophied synovium. On the fat suppression study of this case there was some fatty infiltration, which makes this a differential to think of if this MR alone was considered.