dreaded cake tumor can show up any time. However, I find that it's more likely to happen when a cold cake warms up.
Since I had to deliver a cake that was refrigerated but would be sitting out in 95 degree heat, I was concerned that a tumor would start to appear.
I've heard of people poking holes all over the surface of the cake with a needle to make escape holes for any trapped gas. This cake didn't have a lot of places that would hide holes, so I didn't want to do that. I decided to just cut a hole in the top tier because the fondant on that tier looked suspicious to me for some reason.
It's not something that you have to do, but it can prevent a problem later on.
Kara Buntin owns A Cake To Remember LLC, custom wedding cakes in Richmond VA