The following quote is from the wikipedia entry on Structuralism:
Structuralism is a theoretical paradigm that emphasizes that elements of culture must be understood in terms of their relationship to a larger, overarching system or "structure." In other words, Structuralism posits that discrete cultural elements are not explanatory in and of themselves, but rather form part of a meaningful system and are best understood with respect to their location within (and relationship to) the structure as a whole.
I think that that is very reminiscent of the philosophy of category theory (in solely mathematical terms) in as much it has one. In fact, I would go so far as saying, that category theory is an implementation of this general philosophical idea in the precise mode of mathematics, and has proven itself to be very successful there.
A specific example may show what I mean by this explicitly: Take the simplest mathematical operation we can think of, that of addition. Originally this was defined with respect to the integers, and it was seen that they followed certain rules (ie existence of identity & the associative law). Notice also to add two integers together we don't need the assistance of a third, its solely defined in terms of the two integers we have at hand.
With the birth of modern algebra, and the invention of new mathematical structures, say for simplicity - groups, each of which internally had a notion of addition (you could add two elements of a group to get a third, and in fact this characterises that group), and an external notion of addition (you could add two different groups together to get a third, you also had the existance of an identity & an associative rule, which is why its called addition).
It was noted that in other algebraic systems, the same pattern persisted: you had internal operations which characterised that individual instance of that kind of algebraic system, and an external addition. Now these external additions for each category of algebraic systems were different, and the problem was to come up with a uniform definition. Eventually it was noticed that defining this external addition with reference to every other algebraic system of its kind gave a uniform definition (it generally called a universal property/definition) and furthermore, the definition did not directly refer to the internal structure of any of these systems, but rather how they related to each other (called a morphism in category theory).
Finally, to complete the circle, by using this definition in the category of finite sets (which have no internal operations given), we find that we re-invent the integers.
In contemporary continental philosophy, I'm aware that Badiou uses Category Theory in the later development of his thought, though I can't say I understand what he's doing, so I'm not going to say anything about it. However, see 'Logics of Worlds'. The following is a quote from this site: http://theimmeasurableexcess.blogspot.com/2008/07/badiou-and-deleuze-brothers-in.html
'Badiou employs two different regimes: being/the ontological/set theory and appearing/logic/category theory.'