Current practice of diagnosis and reporting of prostatic intraepithelial neoplasia and glandular atypia among genitourinary pathologists

The criteria for diagnosing prostatic intraepithelial neoplasia (PIN) and lesions suspicious for cancer are described in the literature. However, it is unknown how these are applied in practice by experts in genitourinary (GU) pathology. A questionnaire was sent to 93 GU pathologists in countries around the world with the purpose of surveying current practices. The response rate was 69% including 40 North American pathologists and 24 from other continents. For preneoplastic lesions, the term PIN was universally endorsed by the respondents. PIN was graded by 83%, usually as low/high-grade PIN (LGPIN/HGPIN) or as HGPIN only. Most respondents would usually not report lesions that may qualify for LGPIN. A majority (81%) did not specify architectural patterns of PIN. With both HGPIN and invasive cancer present, 69% would still mention HGPIN. Among the diagnostic criteria for HGPIN were any nucleoli visible (52%), or nucleoli seen in at least 10% of cells (33%). However, 56% would diagnose HGPIN in the absence of prominent nucleoli, most commonly based on prominent pleomorphism, marked hyperchromasia or mitotic figures. The number of cores involved with HGPIN was specified by 50%. Lesions suspicious for but not diagnostic of carcinoma were reported by 45% as atypia, atypical glands or suspicious for cancer and by 42% as atypical small acinar proliferation. The degree of suspicion was further defined by 41%. Our survey data may serve as a guideline to general pathologists on how to diagnose and report atypia and PIN in prostate biopsies.