Cat lump in chin

Question
Our 9-10yo neutered male (orange tabby/mancoon) chin has been getting longer ... looks like the lion in Pink panther... I can feel a soft lump  there before the bone ... he also has some new small dark spots on his lower lip (looks like little dark sun spots)and it appears his mouth is always a little open... maybe because of the extension of his chin pulling skin downward.
Is this something common in older cats, or am I seeing some sort of tumor forming? Thanks in advance for your opinion.


Answer
The latter not the former is correct. That is not normal unless it's the teeth pushing down and that is very unusual.
I would suspect a tumor of some sort is growing at the mandibular symphysis- the spot where the jaw halves meet in the front.

This is going to require a trip to the vet. It is not an emergency but the longer you wait the less chance of successful removal and less damage to the area.

I am hoping that is it a benign tumor but they still need removal.
The spots on his lip are just age related. Some cats get them, some don't.
Please let me know what you find out at the vets.