In medium saucepan, combine chicken, soup, green beans, mushrooms, cheese, mayonnaise and lemon juice. Bring to a boil, stirring occasionally. Pour hot chicken mixture into ungreased 13x9-inch glass baking dish.
Separate dough into 8 biscuits. Arrange over hot chicken mixture in dish. Brush each biscuit with butter. Sprinkle with crushed croutons.
Bake at 375 degrees for 23-27 minutes or until biscuits are deep golden brown and bottoms are no longer doughy.