I "found" that hard as a bone "thing" back there too and went to an ENT (ear, nose & throat doctor.) He scheduled the removal of a tonsil and afterwards informed me that the pillar back there is normal! Leave it alone it is part of the pillars that grow from your thyroid and parathyroid glands.
Seen doctor today peeps, said it's a bone and not to worry. Take her word for it I guess, we're all different. Glad its not a tumour but was told a tumour does not present as a bone texture. Keep it simple if it feels like a bone then its a bone! Thanks for the advice and comments it's much appreciated.
Glad you found out it was only a bone. My ENT removed a healthy tonsil before informing me that it was a bone - a normal pillar! It was months before I could sing again! So glad your doctor was smart and didn't offer to remove your tonsil!