Use of Immunohistochemistry in Routine Workup of Prostate Needle Biopsies A Tertiary Academic Institution Experience

Context.-Diagnostic use of immunohistochemistry has been extensively studied in prostate needle biopsy, but its use in routine practice and the quality assurance and associated cost have not been previously addressed. Objective.-To examine the routine use of immunohistochemistry in prostate biopsies in a tertiary academic institution. Design.-We reviewed reports of 748 consecutive prostate biopsies and we evaluated the turnaround times, the final diagnosis on individual specimens, the intra-departmental consultation rates, and the associated costs. Results.-Immunohistochemistry evaluation was required for 39.4% of biopsies and 12% of blocks (average 1.8 blocks/case). The biopsies with immunohistochemistry were signed out 1.7 workdays later (8.6 versus 6.9 days). The diagnostic breakdown for individual blocks evaluated by immunohistochemistry was Cancer 47.7%; Atypical, Suspicious 10.8%; Small Atypical Glands Adjacent to High-Grade Prostatic Intraepithelial Neoplasia 6.9%; High-Grade Prostatic Intraepithelial Neoplasia 12.4%; and Benign 22.2%. Diagnoses of Cancer or Atypical, Suspicious (Atypical, Suspicious + Small Atypical Glands Adjacent to High-Grade Prostatic Intraepithelial Neoplasia) were rendered in 65.4% of individual blocks assessed by immunohistochemistry. Immunohistochemistry aided in establishing limited cancer (<= 10% of core) in 69.3% of cases and in 74% of single-core-positive biopsies. Departmental consultation was performed in 18.3% of biopsies and immunohistochemistry was used in 68% of these cases. Both immunohistochemistry and consultation were performed in 55.8% of Atypical, Suspicious cases. The average immunohistochemistry cost per biopsy was $22.34 and the estimated annual cost for prostate biopsy immunohistochemistry in our laboratory was $33 420.64. Conclusions.-Immunohistochemistry is frequently used in our prostate biopsy practice to establish or confirm a limited Cancer diagnosis, to better resolve diagnostic ambiguity, or for quality assurance. The data provided herein can be used for comparisons with other prostate biopsy practices.