Hi Kim,
welcome to the site. We can only guess what will happen next or what your prognosis will be. Tongue cancer is always a little more difficult to treat than other forms of oral cancer. My guess is that the node was there all along and somehow they missed it (in other words it is probably related to the original tumor). Did you have a PET scan prior to treatment?

I am assuming that they only performed a surgical resection of the tumor? They may want to perform surgery such as a neck disection (modified or radical) and/or radiation and chemotherapy.

You need to take as aggressive approach as possible and please - be sure to be seen at a comprehensive cancer center and not a local or regional hospital. Your young age and no risk factors actually work against you a little bit and you must be very careful to seek the best medical advice that you can.

In the references section on the main page, there are lists of the NCCN and NCI comprehensive cancer centers.