Note that intervening joint spaces are preserved.
Abnormal signal extends along the flexor tendons and into the plantar soft tissues of the foot.
The mass extends between the third and fourth metatarsals into the soft tissues of the dorsum of the foot. Giant cell tumor of the tendon sheath and pigmented villonodular bursitis are lesions related to PVNS that occur in extraarticular locations. The joint space in PVNS is typically preserved, as in this case. Cartilage destruction does not occur until late in the disease process. In case II where joint space narrowing is present, the lack of productive bone formation suggests that the cause is PVNS rather than osteoarthritis.