Current prostate biopsy interpretation: criteria for cancer, atypical small acinar proliferation, high-grade prostatic intraepithelial neoplasia, and use of immunostains.

Abstract

Abstract Context.—The past decade has brought major changes in prostate biopsy sampling, interpretation, and reporting. Objective.—To summarize current information on diagnostic decision making, Gleason grading, “atypical” diagnoses, and use of immunostaining. Data Sources.—Pertinent literature from 1985 to 2005 is reviewed, emphasizing recent findings. Conclusions.—Diagnosis begins by evaluating a focus of atypical single-cell layer lined acini according to the 3 minimal diagnostic criteria for cancer: an infiltrative pattern, nuclear enlargement and hyperchromasia, and prominent nucleoli. The Gleason score and linear extent or percent of each core containing cancer should be reported. Atypical small acinar proliferation suspicious for malignancy designates foci that have either qualitative or quantitative limitations in atypia precluding a definite cancer diagnosis. It has about a 3% incidence as an isolated finding. Contemporary studies indicate a 39% predictive value for cancer on repeat biopsy. Isola...