@skm101, welcome to Mayo Connect. I'm sorry that you are having to go through this, but I'm glad that you found us. Feeling scared of the unknown is expected. Having more information from the results of the scans and tests will only fill in the gaps and help you to know what to expect.
My cancer was identified at a late stage, with spread to the liver and lymph nodes. The lymph nodes in the center of my chest were enlarged and were placing pressure on my windpipe and esophagus. The largest lymph node at the time of diagnosis was 1.2 cm. Different radiologists will describe enlarged lymph nodes differently, but they usually include an approximate measurement. I had a recent scan that showed lymph node at 2.5cm, but it was confirmed to be fungal, not cancer! Enlarged lymph nodes can mean your body is fighting an infection or fungus, or simply inflammation. It doesn't always mean cancer.

Take a deep breath and try to relax a bit. I'm glad you are having a PET scan this week. Do you have a nodule along with the lymph node activity? Did this show up on a routine screening exam, or were you experiencing symptoms?