M12.2 - Villonodular synovitis (pigmented)
M12.26 - Villonodular synovitis (pigmented), knee
M12.261 - Villonodular synovitis (pigmented), right knee
M12.262 - Villonodular synovitis (pigmented), left knee
M12.269 - Villonodular synovitis (pigmented), unspecified knee