Season catfish fillets with paprika and a light dusting of Old Bay. Broil 10 minutes or until done. Let cool. Gently flake catfish.
Remove stems and gills from mushrooms. Set aside.
Beat cream cheese at medium speed. Add green onions, mayonnaise, lemon juice, Worcestershire, cheese, Old Bay, cayenne pepper and paprika. Gently stir in flaked catfish.
Using a small spoon, fill each mushroom cap with a generous amount of stuffing.
Sprinkle each mushroom with 1 tablespoon breadcrumbs, and place on a lightly greased baking sheet.
Bake at 425˚ F for approximately 15 minutes, or until lightly browned.