I Have A Lump On My Back, Lear The Shoulder

I have a lump on my back, Lear the shoulder blade, which has been there for decades. First noticed it when I was a teenager; it was about the size of a pencil eraser. It moves with the ski and does not seem to be anchored to anything below. There was something similar (size and characteristics) on my leg, removed in my 20s, which the doctor advised me was an infected pore.

Because the one on my back was out of sight and did not hurt, I have pretty much ignored. Now, at 53, it has grown to about the size of a quarter, and is conspiuiously raised enough that my (intimate) partners have commented on it (one called it "the thing the size of a Volkswagen" on my back).

So now, I find myself thinking about it, and sort of obsessing on it. It is not a hard lump, but sort of soft when o press or rub it. When I do, I notice my fingers have this weird (puss like) odor I don't detect when I rub other areas on my back. I asked my GP about it, and he said the risk of surgery (I have hypertension and diminished kidney function) were not worth removing something which has been there my whole life, and seems to have grown very slowly. When I asked him if it might be a tumor, he said something about a 40 year old tissue mass being the least aggressive tumor ever, if indeed that's what it was.

My GP basically said not to worry about it, but he's not the one with a mystery lump on his back grossing out his lover! Does this really sound harmless, or should I consider a needle biopsy or something? Can some type of intervention be done under a local (general anesthesia was my GPs biggest concern) to remove it?

Any help would be most appreciated!

Greg