Pathological Evaluation
A uropathologist with 15 years of experience analysed all RP specimens. Based on the prostate’s regional anatomy, specimens were examined in 3-mm sections in cassettes, starting from the bladder neck and moving towards the prostatic apex, after sampling the apex and bladder neck surgical margins and staining the surgical margins of the prostate. Slices were placed on A4 papers for tumour mapping, and their borders were drawn in pencil. After determining the right, left, anterior and posterior orientation, it was marked counterclockwise starting from 1. Since whole-mount sectioning could not be made, all transverse sections were divided into four pieces to fit the tissue cassettes, taking into account anterior/posterior and right/left discrimination based on the urethra. Hematoxylin-eosin stained sections were prepared after paraffin tissue processing. After tissue sections were examined microscopically, mapping was performed by drawing around the tumour areas on slides. The marked slides were placed on A4 paper according to their locations in the drawn prostate slices during the macroscopic sampling. The tumoural areas identified in the slides were transferred onto A4 paper, and the tumour mapping was completed. Tumour grade groups were reported according to the ISUP 2014 consensus conference[8]. Tumour grade group, tumour diameter, approximate tumour volume, extraprostatic extension, surgical margin and local infiltration status (seminal vesicle and bladder neck), and tumour grade and linear length at the surgical margin, if any, were reported for each tumour. The highest ISUP grade group was determined as the criterion for index lesion selection. The extraprostatic extension was determined as a secondary criterion if there were more than one lesion with the same ISUP grade group. If there were no extraprostatic extensions, the lesion with the largest diameter was determined as the index lesion.