Question: Does the existence of evil impinge on atheist philosophy, such that it could be seen as a "problem" with, and not just within, these philosophies in a similar way too theism?

Could e.g. Marxism be seen as a response to that kind of dilemma?

Answer: 
The Problem of Evil exists in theism because theists need to provide an explanation for how evil can exist in a world created by an infinitely benevolent deity. Since atheists deny claims about the existence of said deity, the problem simply does not exist. The existence of evil does not by itself present a problem to atheism.
You could argue and this has been the case with some theist that atheism has a big problem with explaining the problem of goodness. In other words how does the atheist explain how any apparent goodness in some people?

On what basis does the human animal decide post coitus cannibalism is abnormal when the black widow spiders of Africa find this common place?

If we are just a more evolved form animal then where do these un-animal like morality we seem to have come from?