+TG - WBS/PET/CT neck

Is there anyone who has + thyroglobulin rising, - WBS/-PET/-CT neck. Pet showed lung nodule 13x10mm non calcified lower left lung.  I am really confused. My Oncologist is sending me Mayo Clinic in Minnesota. She said I am the 2nd case in 18yrs she has come across.  Can anyone help me with information for guidelines, or they own experiences.

thanks
becky