Villonodular synovitis (pigmented), unsp ankle and foot

This code identifies a benign, proliferative synovial condition characterized by villous and nodular growth within a joint, tendon sheath, or bursa, often with hemosiderin deposition (pigmented). It results in chronic inflammation, pain, swelling, and can lead to joint destruction.

Assign this code for documented cases of pigmented villonodular synovitis affecting an unspecified ankle or foot. This diagnosis is typically confirmed via imaging (MRI) and often definitively by biopsy or surgical pathology.

• Ensure documentation specifies "pigmented" villonodular synovitis; otherwise, consider other synovitis codes.
• Avoid using this code if a more specific anatomical site (e.g., right ankle, left foot) is documented; look for laterality-specific codes.
• This code is for the diagnosis itself; procedures to treat PVNS (e.g., synovectomy) would be coded separately.