Wrap the tortillas in a damp kitchen towel and place them in the microwave until they are warm and pliable. Or, place a skillet over medium-high heat and heat up the tortillas one by one, about one minute on each side.
In a bowl, combine the tuna, avocado, and tomato. Spread a spoonful of hummus on each of the tortillas then top with the tuna mixture. Roll up each tortilla, cut them in half, and serve with a lemon wedge.