fatty lipomas are common in some older dogs of certain breeds.
in my breed.....the doberman......it is seen in many senior dobes, especially if they have a low thyroid function.
i have never seen one on a paw pad though.
I wonder if it could be a cyst or a foreign body abscessing.
Hope all goes well at the Vet's.
please let us know what you find out.
Hugz to limpy!