David Bryan, M.D. 's Urology Blog

Precancerous Lesions of the Prostate.

Not all prostate biopsies are negative.  Not all are positive.  Some are “in between.”  High Grade PIN is a lesion noted in about 15% of biopsies that, from a cellular architecture, is benign.  It does, however, require close follow up, and in more involved cases, repeat biopsy.  The link above provides a comprehensive overview.