I think one of my students might be a Nazi.

Okay, so I teach literature (specifically West Indian lit) at a very culturally diverse college. I week ago I noticed that one of my students has a swastika drawn on the inside of his binder. I thought it was weird, but he left before I had the opportunity to mention anything. In this week's class we were talking about post-colonialism and the literary canon--In order to get inot a discussion of what the canon is and its importance, I asked the class to name some supposedly "important" works (my point was to simply bring up the fact that most of the writers our soicety thinks are quality are often written by white dudes--simple jumping off point) and the swastika boy says "Mein Kampf". I could tell that folks in the class were taken aback--I said something about "Mein Kampf" being more of a historical document than a piece of literature and tried to explain myself, but the guy just put his head down on his desk and then, as soon as some students got into a discussion about what effect changing the canon has on societal attitudes (making reference to Haiti and the lack of support for Haitians--the fact that no one really listens to what Haitians have to say...) and the guy got up and left. What should I do? Should I take him aside next class? Should I ask him about the swastika? How should I deal with this situation?