Biopsy materials obtained in the American Cancer Society National Prostate Cancer Detection Project were reviewed at the Central Pathology Laboratory at the Armed Forces Institute of Pathology. Of 265 cases submitted, 177 were diagnosed as prostatic carcinoma, 7 as prostatic intraepithelial neoplasia (PIN), 13 as atypical glands or atypical hyperplasia, and the remaining 68 were benign hyperplasias. Irrespective of the means of detection or the grading system used (Gleason or WHO-Mostofi), a large majority of the cancers were detected as low-grade tumors. Of 27 cases of PIN reported, 20 were associated with cancer, leaving 7 cases with the sole diagnosis of PIN. These data may indicate the increased use of prostate-specific antigen (PSA), digital rectal examination (DRE), and transrectal ultrasound (TRUS) in the United States is shifting the spectrum of prostate cancer pathology toward early low-grade tumors. © 1995 Wiley-Liss, Inc.