What is high grade prostatic intraepithelial neoplasia?

Finished my first week of radiation for my prostate cancer stage 1 grade 2. My urologist fully explained I.had 2 areas 3+ 4 and 1 area 3+ 3. That made my case a grade 2. When reviewing my results 1 biopsy also showed High grade prostatic intraepithelial neoplasia. I dont remember my urologist describing what that was. I looked it up and it pre cancer tissue lurking around that area of the prostate. Ill ask my urologist how or if thst is being treated