They didn't seem real optimistic because 80% of the time if you have a mass that large, over 3 cm, on your lung it's probably going to be malignant. When I first saw the pulmonologist he did tell me that it didn't look like cancer to him but that didn't mean that it wasn't. So he was the first one that gave me some hope! When I had the pet Scan the pet Scan actually showed that it was hyper metabolic, and that's what cancer shows up as, but the impression on the pet Scan said that it seemed to be more of an infection than to be a neoplastic process (cancer). Even after being diagnosed with Mac, my doctor ordered another biopsy because they wanted to take a chunk and see if it was cancer off of the cavity lesion in the lung, but when they did the first round of scans it showed that things were already healing and the satellite nodules had largely dissipated that had been around that mass and the radiologist just told me that cancer doesn't shrink so they deferred it.
I've heard of a couple other people having some strange things going on with their ones now. There is something called long covid where you can develop these like things that look like cancer on your lungs from having covid, and also been cases of people developing these masses on their lung from vaping (although rare) you're so young I just highly doubt that cancer is what it would be. I definitely have a lot of Hope for you that it's not that!!!