Can someone help me with this white bump on my cat's toe?

Hi,
I've noticed this white sort of bump on the one of the toes of my cat's back left paw. After some pretty excessive Google searching I've come across nothing that seems to match it, via photo or text description. I'll include a couple of photos, but sadly a combination of God awful low energy light bulbs we have to use in the UK now, and my phone's autofocus being atrocious at close detail the results aren't the greatest. I can try to take better ones in daylight if required.
The lump itself isn't red like it can look in those photos, that is just the crappy light sadly. The loss of hair is from me plucking it with some tweezers to get a look at the issue, as cat toe hair is extremely awkward to hold to one side!
Anyway, I'm sick with worry, and need at least even a vague idea of what it could be!

Thank you.

Is it on the pad? Does it feel hard? How old is your cat?

Hi.
It's just above the pad on the skin. It's harder than normal skin, but soft as well if you get what I mean. It's hard to feel it well due to the location.
She is 9.

My older cat had long callouses but they grew on the pad vet said its normal. Sorry yours seems something different.

She has those callouses too.

It maybe another type callous.