Preheat the oven to 400 degrees F (200 degrees C). Line baking sheets with aluminum foil.

Crumble and cook sausage in a skillet over medium heat until no longer pink and lightly browned; drain.

Remove and discard mushroom stems; arrange caps on the prepared baking sheets.

Combine cooked sausage, cream cheese, bread crumbs, parsley, garlic, and lemon juice in a bowl; stir until blended. Spoon sausage mixture into mushroom caps; sprinkle with Parmesan cheese.

Bake in the preheated oven until mushrooms are tender and lightly browned, 14 to 16 minutes.