Diagnostic effect of an improved preembedding method of prostate needle biopsy specimens

The authors compared the influence of a conventional and an optimized submitting method of prostate core needle biopsy specimens on the frequency of cancer detected and the pathologic characteristics of the adenocarcinoma bearing biopsy specimens. The patients included were part of the prostate-specific antigen (PSA) screening program of Tyrol/Austria. Of the systematic core needle biopsy specimens from 500 unselected men obtained within 1 year from the Urological Department, University of Innsbruck, the core biopsy specimens of 250 cases were submitted conventionally, floating free in formalin-filled containers, whereas the biopsy specimens of the other 250 cases were stretched and orientated between 2 meshes in tissue cassettes at the time of biopsy before formalin fixation. On 136 cases diagnosed as adenocarcinoma the number and the length of cores as well as number of the cores involved by cancer and the tumor size were morphometrically determined. The diagnosis of benign prostatic hyperplasia, isolated high-grade prostatic intraepithelial neoplasia (PIN), atypical foci suspicious for cancer, and carcinoma was made in 66%, 5.6%, 4.8%, and 23.6% after conventional submission and in 61.6%, 6.4%, 1.2%, and 30.8% of the cases after optimized preembedding respectively. In the adenocarcinoma cases the optimizedly preembedded material showed higher mean total core length (126.5 mm versus 93.9 mm; P < .0001), a higher mean total tumor length (14.1 mm versus 8.6 mm; P = .01), and more cores involved by cancer (2.9 versus 2.4; P = .01) compared with the conventionally worked-up biopsy specimens. Optimized preembedding of core needle biopsy specimens in tissue cassettes could be quickly and routinely done by the assistance of the urologists at the time of biopsy. The significant improvement of the histologic yield of optimizedly preembedded prostatic needle biopsy specimens led to a higher frequency of cancer diagnosis, a reduction of cases with atypical foci suspicious for cancer and a significantly lower number of cases with only 1 core biopsy involved by cancer.