Method for procuring specific populations of viable human prostate cells for research

A wider range of research can be conducted on viable tissue samples than on fixed or frozen samples. A major obstacle to studying viable prostate tiss ue samples is the inability to accurately identify cancer on direct examina tion of unembedded tissue. We used a dissecting microscope to identify canc er in unfixed prostate tissue samples stained on the cut surface with 0.5% aqueous toluidine blue. We measured the diagnostic accuracy of this techniq ue in 25 consecutive prostatectomies, determined the viability of procured samples, and estimated the effect on final pathologic assessment. Both surf aces of a 3- to 5-mm thick cross-section taken midway between base and apex of the prostate were examined. A 4-mm punch biopsy was directed to one ben ign and one malignant area when clearly present. The dissecting microscope allowed clearcut recognition of carcinoma in 17 of the 25 cross-sections, a nd carcinoma was confirmed in all 17 (100%). In 8 of 25 cases, no procureme nt was attempted because no carcinoma was evident in the one cross-section studied. Twenty of 25 cross-sections were adequate for benign tissue procur ement; five of the cross-sections were not suitable for procurement because of the presence of extensive carcinoma or atrophy. Seventeen of the 20 wer e accurately diagnosed as benign (85%); one showed pseudohyperplastic adeno carcinoma, one showed focal high-grade prostatic intraepithelial neoplasia, and one showed urothelial carcinoma in situ. Prostatic epithelium obtained with the technique remains viable and can be separated from stroma. The di ssecting microscope technique appears to facilitate rather than interfere w ith accurate pathologic assessment: extraprostatic extension or positive ma rgins were correctly identified during tissue procurement in three cases. T he procedure takes only about 30 minutes.