Impact of the Pathologist on Prostate Biopsy Diagnosis and Immunohistochemical Stain Usage Within a Single Institution.

Objectives: To determine whether pathologists in a tertiary care institution vary in diagnosis and immunohistochemical stain usage in prostate biopsy specimens.

Methods: Men who underwent prostate needle biopsies between 2008 and 2013 were included.

Results: In total, 1,777 prostate biopsy specimens diagnosed by nine pathologists showed variation in diagnostic reporting (atypical small acinar proliferation, 2.0%-8.0%; high-grade prostatic intraepithelial neoplasia, 2.0%-8.5%; nonneoplastic, 30.2%-48.3%; adenocarcinoma, 46.2%-55.3%; P < .001). Variation in Gleason scoring was observed (P < .001), with the 4 + 3 = 7 category having the greatest variability (6.9%-30.3%). A blinded review from the most outlying pathologist in this category revealed 45% grading discrepancies. The mean number of immunostains performed per case (0.3-1.2) differed between pathologists (P < .001), and one pathologist used immunostains at twice the rate of the remaining cohort.

Conclusions: Case pathologist significantly affects prostate biopsy diagnosis and immunohistochemical workup. We recommend evaluation for outlying practice patterns to provide consistent and efficient patient care.