Thanks for writing to H.C.M. about your query.
I have gone through your clinical history and a node on your left side of neck is an important and suspicious finding. It is painless which indicates its nature to be chronic. since you are a follow up case of cancer thyroid
therefore these investigations are necessary for you-
(1) M.R.I. of neck.
(2) F.N.A.C. from node on neck.
(3) Doppler study of thyroid area of neck.
(4) X-Ray Chest - P.A. view.
After this much work we can reach to a point to make a diagnosis which than accordingly be plan for treatment.