PATOLOGY

Needle core length in sextant biopsy influences prostate cancer detection rate
Iczkowski KA, Casella G, Seppala RJ, Jones GL, Mishler BA, Qian J, Bostwick DG
Department of Pathology and Laboratory Medicine, University of Florida, Gainesville, Florida; Berks Urological Associates, Wyoming, Pennsylvania, and, Bostwick Laboratories, Richmond, Virginia
Urology 2002; 59:698-703

• Objectives: Prostate cancer detection in biopsies increases with the number of sites and total tissue sampled. Its dependence on needle core fragment length is uncertain.
• Methods: Two consecutive series of sextant needle biopsies were surveyed from two practices in 1998 to 2000: 251 patients from Pennsylvania (group P) and 1596 from Virginia (group V). The gross needle core lengths per sextant site were tabulated and the diagnoses classified as benign or nonbenign. Logistic regression analysis was used to correlate cancer with the total length (sum of six sites), with the length per single core, and the anatomic site of origin (apex, mid-gland and base).
• Results: The mean total tissue length sampled was 108 ± 27mm (range 30 to 275) in group P and 81 ± 22mm (range 30 to 228) in group V. Considering single cores the mean was 12.8 ± 3.5mm tissue. Group V core lengths at the apex averaged 11.8mm, shorter (p=0.0001) than mid (13.3mm) or base (12.7mm). A predictive value of longer length for a nonbenign diagnosis was noted in four of six sextants (p<0.04), with trend strongest at the apex, for which detection was influenced by abnormal digital rectal examination (p=0.02) or ultrasound (p=0.04) findings.
• Conclusions: Significant trends were noted for more detection of cancer and nonbenign findings in sextant prostate biopsies as longer single cores were sampled, particularly at the apex. Biopsy tissue length is at least as influential as the number of sites sampled and should be examined before submission for quality assurance.
  
  
• Editorial Comment
  This paper called my attention at the American Congress of Pathology held this year in Chicago. Sample is of utmost importance for the pathology report. The absence of carcinoma in a case that all fragments of the biopsy have less than 10mm of length certainly subevaluates the existence of a tumor. Many times this fact is neglected by both the pathologist and the performer of the biopsy. Considering that a needle prostatic biopsy may obtain fragments up to 20mm in length, the minimal accepted length would be fragments with 10mm. Its is very important that the performer of the biopsy be aware of the length of the fragments repeating immediately the biopsy from sites that the sample is insufficient. The pathologist must also be aware to this detail, informing the length of each of the fragments received for analysis, and commenting in the report whenever the sample is insufficient for an adequate estimation regarding existence of a neoplasia. This is critical when evaluating “insignificant” carcinoma according to the criteria proposed by Epstein in stage T1c (J Urol. 1998; 160:2407-11). When the tumor occupies more than 50% of the area of the fragment it is considered significant. Considering that it occupies 100% of the area of a fragment with less than 5mm length, obviously, this finding is not a criterion to exclude the tumor as “insignificant”.

Dr. Athanase Billis
Department of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil