Where I live, every pizza is made with Mozzarella cheese on it, unless you specifically request that it be made without cheese.
Maybe there can be a special variant of lactose-free pizzas, but that would require more work on the part of the developers.
On an unrelated note: The only reason I came to this thread is that it showed up as the last post in the Garage section of the forum, and the title was shortened to "Re: 21751: pizzas (excep...". All I read was "21,751 Pizzas", then I clicked on it. I must say, I'm kinda disappointed.