Any ideas? Could it be a lymph node?
Are you experiencing any pain in your throat? I don’t really understand how do you mean that the lump is not under the skin or on top of the skin? It’s little confusing to imagine this.
However there is a good chance that this really is a lymph node. It can be cause of enlarged thyroid gland. However they only get swollen if you have some infection in the body. Are you experiencing any other medical problems? Maybe if you are having a cold or you had a cold some time ago. Any infection in the mouth can be related to this problem so it is important to eliminate as much as causes as possible.