Once fine needle aspiration cytology is normal cancer is ruled out. Colloidal cysts are very common lesions and usually benign. She might be taking levothyroxine tablets which might have raised T4 levels. She needs to stop any
thyroid replacement medicines. Usually colloid cysts are not painful and other causes for neck pain needs to be ruled out
Next Steps
Consult nearby ENT specialist for confirmation of diagnosis and appropriate treatment if required