I went through the same diagnosis 2 years ago when I turned 50 years old, with no family hx of PCa, 1 out of 10 initial biopsy samples came back atypical. As mentioned this means the sample could not be called positive or negative, but some abnormal cells seen. My PSA never went above 0.85, but I had a positive DRE. I also went back in 6 weeks later for another biopsy but this time I was put under general anethesia and had 22 template core biopsies completed. The result was 1 out of the 22 came back positive for PC. Ten weeks later I went in for a RALP and have been PCa free since on all further follow-ups.
If possible I would see if you can have a template biopsy performed, ask your Urologist if they do that type of testing. You can also send your slides for a second opinion, but in my case they came back with the same results. Good luck with your PCa journey, let us know how you are doing and if you need anyone to talk with, many helpful PCa brothers on this site!