There's a lot in this message that is confusing. Squamous mucosa is what the entire inside of a normal mouth is lined with, so there must be something more to the pathology report, or this is finding things normal. If they want to do a fine needle biopsy, this is likly not in his mouth, but in a node in his neck, meaning that the have suspicions from the scans that it has metastasized outside of his mouth to his neck. If he has had a surgical only solution to the cancer the first time around (no radiation and no chemo) it could be that the doctor didn't get it all, or has realized that there was a positive cervical node at the time that wasn't addressed, and he needs to go to the best place possible to get things back in control, and that would be a comprehensive cancer center, of which the university in WA is one of the best.

Once at a comprehensive cancer center, they will likely redo any tests that local doctors have done (to be sure they know exactly what's what since they are taking over treatments), so if they are saying that he needs more treatment, just get the referral from them and get to Seattle, don't waste any more time. Your posting says you are in Michigan, there are good centers near you, but I am assuming he is on the west coast.