Divide pizza dough into 3 pieces. On a lightly floured surface, roll each piece of dough into a 6 inch circle. Spread 1 tablespoon of pesto on top of half of each circle to within 1 inch of the edges. Top pesto with 1/3 of the shrimp, 1 tomato slice, and 1/3 of the cheese.
Moisten edges of dough on each circle with egg white. Fold each circle in half. Seal edges with the tines of a fork to prevent filling from oozing out while baking. Prick tops once or twice. Brush with remaining egg white.
Baked on a greased baking sheet with a lip in a 375 degree F oven for 20-25 minutes or until golden.