Could a university annex itself away from a city?

Here in Pittsburgh, the mayor is proposing a 1% tax on higher-ed tuitions

Two larger universities are Pitt and Carnegie Mellon, who own pretty much all of the land surrounding their campuses, to the point that the two of them make up a rather huge contiguous area if you combine the two.

I also know that it’s relatively straightforward to create a city out of unincorporated land—this is the story behind City of Industry—however, is it possible for an incorporated chunk of land to become a separate city?