It looks like a skin growth similar to what my dog has. My dog has a tendency to grow many fatty lumps. None of them bother him. However, in every case, my Vet takes a biopsy and we watch the lumps, just in case.
My philosophy, discussed with my Vet, is prevention. If a benign lump can possibly cause a problem, especially when my dog is a senior, then I'd prefer to remove them when he is young. In 11 years, she has only removed two benign growths, and those were incidental to other procedures.
Discuss the growth with your Vet.