Preheat oven to 400ºF.
Remove mushroom stems and discard; set caps aside. Place mushroom caps on foil-lined baking sheets; set aside.
Remove sausage casings. In a skillet, cook and crumble sausage over medium heat until no longer pink; drain.
Remove from heat. Stir in bread crumbs and set aside.
In a bowl, combine the cream cheese, parsley, lemon juice, and garlic until smooth.
Combine cream cheese mixture and sausage.
Fill each cap with sausage and cream cheese mixture. Sprinkle with Parmesan cheese.
Bake for 14-16 minutes or until mushrooms are tender and lightly browned.