I underwent a tonsillectomy 15 years ago. Recently, I could feel a swollen lump of tissue where the tonsil once was. The swelling is limited to the right side of my mouth. Of course I am having this looked at by an ENT soon, but until then, what are the possible causes of this? I am HPV positive so I know that oral cancer is one possibility. However, does leftover tonsil tissue act as a lymph node? I recently had a cut on my upper back close to this region of my neck, so I wonder if my body is fighting off an infection.