Eighteen years ago, I felt a pea-sized lump in my neck that the doctor couldn't detect, so he put me on anti-biotics. After two weeks, I was sent to an ENT, who did a needle biopsy from the offending lymph node which had increase in size, extracting substantial fluid that came back positive for basil cell carcinoma. Scoping the throat revealed a small tumor on the base of my tongue. A PET scan showed lymph nodes on both sides of my throat were cancerous. A second scan after radiation and surgery still showed some cancer remained, so surgery was scheduled, which occurred 3 months after I had completed my radiation treatment. There was no cancer present at that time. I can only assume the radiation was still having an effect during the interim. I know they have come a long way since then, so hopefully you will get a quick resolution. Good luck!