Good news on the results.
I had the same issue on the tip of my nose back in 2012!
As those of you know who ride with a full face helmet (no, not modular but a real solid full face helmet) the face is right there in the sun. For the last 12 years all my helmets have also had a drop down sun visor inside the clear visor and with those only the tip of my nose is full exposure to the sun. Sure, the visors on good modern helmets are polarized but still the sun shines through. Add to that I grew up working through middle school, HS and some college as a public pool life guard. And even before that spent almost every day, all day, at the outdoor pool during summers as long as I can remember. My dad was HS PE teacher, swim coach, summer public pool manager, Red Cross swim lessons organizer, etc. So everything was about being out in the sun. I would usually end up turning as red as a lobster in full boil by Memorial Day and that would peel off to a very dark brown by 2 weeks later. I'm actually very surprised I didn't get cancer earlier or have had it much more often. My dermatologist says that usually a second or third or more skin cancers show up within a few years after the first is removed. But so far nothing is showing up again. Fingers crossed here.
Hope it stays away for you as well. But keep going to those checkups just to be sure.