Villonodular synovitis (pigmented), unspecified site

This code describes villonodular synovitis, a benign proliferative disorder of the synovial membrane characterized by villous and nodular growths. It can be pigmented (PVS) due to hemosiderin deposition or non-pigmented. The condition typically affects joints, tendon sheaths, or bursae.

Use this code when documentation confirms a diagnosis of villonodular synovitis without specifying the affected anatomical site. This is appropriate when the provider has not documented laterality or a specific joint/site. Supporting documentation would include pathology reports confirming the diagnosis or physician notes explicitly stating "villonodular synovitis, unspecified site."

• Avoid using this code if the specific anatomical site of the villonodular synovitis is documented; instead, use a more specific code from the M12.2 subcategory.
• Ensure the documentation clearly indicates the "unspecified" nature of the site to justify using this code.
• Differentiate from other forms of synovitis (e.g., M65.8- for other specified synovitis and tenosynovitis) based on the specific pathological findings.