I had one in my arm. My GP told me it was nothing, and they really are nothing, and took it out right there in his office. It came back. When it came back about a year later I had it removed by a plastic surgeon and that was the end of it. That was about 15 years ago. That particular one never came back and I haven’t had another one, anywhere since. And there not dangerous. You should have any lump biopsied, I think, but if it truly is a lipoma the biopsy will come back negative. Finding a lump anywhere on your body can be scary but all lumps are not equal. Many are not dangerous at all. That being said, I was still glad to be rid of it once and for all.
It’s extremely rare that any lipoma might be or become dangerous, really. They are benign, first of all. But, if you’ve got one growing internally, not under the skin and grows long enough and becomes large enough to start impinging on some vital organ, then maybe, but really, they are not something to get too worried about.