LIMITATIONS OF TRANSITION ZONE NEEDLE-BIOPSY FINDINGS IN THE PREDICTION OF TRANSITION ZONE CANCER AND TISSUE COMPOSITION OF BENIGN NODULAR HYPERPLASIA

Objectives. The transition zone of the prostate is the origin of 30% o f all prostate cancers and of almost all benign prostatic hyperplasia (BPH). We compared histologic findings in transition-zone biopsies to tissue composition of the transition zone from radical prostatectomy s pecimens from the same patients to determine the efficacy of needle bi opsies to evaluate either cancer or BPH.Methods. A quantitative evalua tion of the transition zone for both cancer and BPH in 21 retrospectiv e and ii prospective radical prostatectomy specimens was made. All ret rospective cases had transition-zone biopsies prior to radical prostat ectomy; all prospective specimen transition zones were biopsied after surgical removal with an ink-filled needle to trace the needle tracks after specimen processing. For all 32 specimens, total prostate weight , width of transition zone, transition-zone tissue composition, and ep ithelial/stromal (E/S) ratio of nodular and internodular BPH tissue we re noted; the corresponding biopsies were evaluated for the amount of cancer and the composition of nodular and internodular tissue. Results . Eight carcinomas larger than 5.0 cc were detected at biopsy, whereas 5 cancers smaller than 2.0 cc were undetected. Biopsies did not relia bly predict BPH tissue composition or epithelial density of prostatect omy specimens; both were markedly underestimated. Dyed needle tracts s howed selective sampling of internodular tissue versus nodules by biop sy as an explanation for low correlations. Conclusions. Transition-zon e needle biopsies efficiently detect cancers larger than 5.0 cc and mi ss cancers smaller than 2.0 cc. Biopsies do not reliably predict BPH t issue composition because of selective sampling of the internodular ti ssue. Copyright 1996 by Elsevier Science