Clean mushrooms. Remove and dice the stems and set aside. Brown the sausage until no longer pink, adding the diced mushroom stems when the sausage is nearly done. Add the soup, cheese and breadcrumbs to the mixture and mix well. Remove from heat.
Stuff the mushroom caps with the sausage mixture and transfer to an oven-proof casserole dish. Bake at 350 degrees for 30-40 minutes or until piping hot - baking time will vary a little based on the size of the mushrooms. Serve immediately.