Mix mayonnaise, Parmesan cheese, lemon juice, anchovies, garlic, mustard and Worcestershire sauce in small bowl until well blended. Stir in milk. Refrigerate dressing until ready to use.
To serve, toss lettuce and croutons in large bowl. Add dressing; toss to coat well. Sprinkle with black peppercorn grinder and additional Parmesan cheese, if desired.