Yup to what david said. Cancer can seed to different places. If it comes in contact with a blood supply (which ultimately it has to to survive) it can spread to anywhere. It does have it's favorite routes. With head an neck cancer it's often the neck nodes. So what is likely to have happened is you have a primary tumor. It seeds to the nodes (one or two cells sit there dormant)

There is a theory that the Primary tumor is the boss, but like bad employees - when the boss is gone the employees begin to do their own thing.

There is also the possibility that during surgery some of the cells break away and end up in the nodes (the lymphatic system cleans the blood so it makes sense anything unusual in the blood would end up in the lymph nodes).

Regardless - this is why most surgeons who know oral cancer and deal with it all the time - tend to take a certain number of nodes as well. Particularly if the pathology comes back saying this is an aggressive cancer and it's non HPV.

This is why doing the minimal when treating cancer doesn't always sit well with me. No one every complained of having too much treatment... only too little.

hugs