Macroscopic features of prostate cancer

Abstract

This study investigates the macroscopic features of prostate cancers in unfixed prostatic tissue. For the study 514 radical prostatectomy specimens received at the Karolinska University Hospital were examined. The glands were bisected horizontally prior to fixation. Features on the cut surface of the prostate that were considered conclusive or suspicious for cancer were seenin 52% and 24% of specimens, respectively. In microscopicsections from these areas substantial cancers (≥2 mm) were found in 94% and 69%, of glands, respectively. When no cancer was seen grossly, substantial cancers were still identified histologically in 56% of cases on the cut surface of the prostate. Of substantial tumours 58% had distinct gross findings and 20% were considered to be suspicious for cancer on macroscopic examination. It was noted that gross assessment of the tumour diameter usually underestimated the microscopic extent of the tumour (p < 0.001). Of tumours that could be identified conclusively, 30% were tan, 30% white, 16% yellow and 24% orange. Transition zone tumours were most often orange (61%) while peripheral zone tumours were usually tan or white (35% and 33%). All macroscopically identifiable cancers were poorly circumscribed. Among substantial cancers, transition zone tumours were less frequently visualised than peripheral zone tumours (33% and 13%, respectively; p < 0.001). Findings conclusive for cancer macroscopically usually predict microscopic cancer, but substantial cancers may be present even if no cancer is seen grossly. Transition zone tumours are more difficult than peripheral zone tumours to visualise macroscopically.