I understand your concern.
I hope the thyroid
levels are well within normal range. It is better to get it examined by an ENT specialist
to look for any local causes like tumors since your thyroid is normal.
It can be a benign swelling or even a simple enlarged lymph node
. Chronic inflammation in the throat can also lead to lymph node enlargement.
A biopsy of the lump will confirm the diagnosis.
You can also get the upper GI endoscopy
Hope this helps.