Utilization of high molecular weight cytokeratin on prostate needle biopsies in an independent laboratory

Objectives: Immunoperoxidase staining of prostate tissues with antibodies to high molecular weight cytokeratin, which selectively labels basal cells, has recently been shown to be useful in the diagnosis of prostate cancer in academic centers. A growing sector in pathology is large independent laboratories, where little is known regarding practice patterns. The following study evaluated the use of high molecular weight cytokeratin in an independent laboratory specializing in prostate needle biopsies. Methods: In a 2-month period (July 1, 1994 to August 31, 1994), 4047 prostate needle biopsies were evaluated. Results: Without the use of ancillary studies, 2710 (67%) were diagnosed as benign, 978 (24.1%) were diagnosed as cancer, and 23 (0.6%) were diagnosed as high-grade prostate intraepithelial neoplasia. The remaining 336 atypical cases (8.3%) were further evaluated with antibodies to high molecular weight keratin. Of the 336 cases, 253 (6.2% of total) were resolved as diagnostic for cancer, 68 (1.7% of total) were diagnosed as benign, and 15 (0.4% of total) remained atypical. The cost of performing high molecular weight cytokeratin was approximately $5.00 per case, which was not passed on to the patient. Conclusions: The use of high molecular weight cytokeratin decreased the rate of an atypical prostate biopsy from 8.3% to 0.4% at a negligible cost to the pathologist and patient.