Villonodular synovitis (pigmented), unspecified shoulder

This code represents a benign, proliferative condition of the synovial membrane, characterized by the formation of villi and nodules, often with hemosiderin deposition (pigmentation). It results in chronic inflammation and can lead to joint damage, typically affecting the shoulder joint in this instance.

Use this code when documentation specifies pigmented villonodular synovitis (PVNS) or giant cell tumor of the tendon sheath affecting the shoulder, without further specification of laterality. Supporting documentation would include pathology reports confirming PVNS, imaging findings consistent with the condition, and clinical notes detailing the diagnosis.

• Ensure documentation specifies "unspecified shoulder" if laterality is not documented. If laterality is known, use the more specific codes (M12.211 for right shoulder, M12.212 for left shoulder).
• Do not confuse with other forms of synovitis or arthropathy; PVNS has distinct pathological features.
• Confirm the diagnosis is indeed pigmented villonodular synovitis, as other villonodular conditions exist.