With so much behind, unless you squarely put him on a big made hand (which you don't), you do have to call. What do you mean by "all in for around $90", you have a $270 stack... do you mean you wish you had 50bb?

If I had 50bb I'd push, yes. With 100bb I'm calling here. I probably call any river bet on a blank, he probably has Kx or a combo draw. If something completes on the river, I think about it some more.