Individual submission and embedding of prostate biopsies decreases rates of equivocal pathology reports

Abstract

Objectives To determine whether the use of biopsy kits with 6 to 12 containers in which biopsies of the prostate are individually submitted and processed reduces the monthly rates of equivocal diagnoses. Methods We searched our computer records for prostate needle biopsies submitted in 1 to 2 containers between July 1998 and June 2000 (group 1, 515 patients) and biopsies submitted individually in 6 to 12 containers between January 2001 and December 2002 (group 2, 933 patients). We analyzed the patient demographics and pathologic diagnoses between the two groups, including the rates of equivocal diagnoses, which included atypical gland suspicious for adenocarcinoma (ATYP) and high-grade prostatic intraepithelial neoplasia (PIN) with adjacent ATYP. Results Group 2 had statistically significant reductions in the monthly rates of equivocal diagnosis (2.8% versus 6.0%, P = 0.003), ATYP diagnosis (1.8% versus 3.5%, P = 0.042), and PIN with adjacent ATYP diagnosis (1.0% versus 2.5%, P = 0.038). The differences in the monthly prostatic adenocarcinoma rates (36.9% versus 35.9%, P = 0.388) and high-grade PIN rates (13.5% versus 12.3%, P = 0.311) between the two study groups were not statistically significant. Conclusions Multiple needle biopsies submitted in 1 to 2 containers tend to entangle and fragment and are difficult to embed in a single plane during processing. The resulting loss of tissue surface area makes a definitive diagnosis difficult on small foci of atypical glands, resulting in equivocal pathology reports. The results of our study indicate that individual submission and processing of prostate biopsies in 6 to 12 container kits reduces the monthly rates of equivocal diagnoses.