One Swollen wattle on pet Pekín bantam, advice please

[Pekin bantam pet owner]

We have 2 hens and 1 cockerel as family pets. They normally are free range in the garden in the daytime and she roosts in the coop at night. The hen with swollen wattle is the eldest, about 8 years old, the others we hatched about 5 years ago. I’m not aware of any pecking problems, she seems to get on best with the cockerel.
I’m not aware of anything that could have caused the swelling. It seems to have got larger over the last week.
She is otherwise well. They have ad lib food and water so difficult to estimate but still enjoying free ranging. The other hens are well.

 

[Eggcessive]

I would guess that could be squamous cell cancer, although it could be an abscess filled with hardened pus. You could lance it and try to squeeze out any pus inside. Or leave it alone.