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.