Unroll the Pillsbury pizza dough on a greased baking sheet. Press to about 14 inches x 9 inches. Bake for 8 minutes then remove from oven. Spread the 1/4 cup of thousand island dressing over the crust, all the way to the edges. Top with the chopped corned beef, drained sauerkraut, and 2 cups of Swiss cheese. Carefully roll up the pizza into a tube. Place the pizza roll into a 9x5 inch loaf pan, seam side down.
Drizzle the top with the remaining thousand island dressing and shredded cheese. Continue baking for 10-12 minutes longer or until cheese is bubbly in the center. Carefully remove from pan and slice to serve. Enjoy!