lump on shoulder

Question
my 14 year old female cat has a large lump on her shoulder (about 1" high x 1" wide) what could this be?

Answer
Hi there! Has she had any vaccinations lately (within a week)?  Vaccination sites can have a lump until the vaccine is absorbed into the blood stream.
I would however recommend a vet visit, as anytime there are lumps and bumps on a pet, it is always beneficial to have them checked out.  There is also a form of cancer that cats can develop from actually getting the vaccines, and because this is on her shoulder (which is a vaccine site), I would definatley have it checked now, so if it is this, it can be caught early and removed successfully.
I hope this helps and please let me know how she's doing!
Hilary