Adequate tissue sampling of prostate core needle biopsies

Area of Science:

• Uropathology
• Oncology
• Diagnostic Pathology

Background:

• Prostatic carcinoma diagnosis increasingly relies on small foci identified in core needle biopsies.
• The adequacy of tissue sampling for these small foci remains under-investigated.

Purpose of the Study:

• To investigate the necessary sampling protocols for detecting prostatic carcinoma on core needle biopsy specimens.
• To determine the minimum number of slides required for comprehensive lesion detection.

Main Methods:

• Review of 229 cases including atypical foci, high-grade prostatic intraepithelial neoplasia (PIN), and carcinoma.
• Preparation of six core specimens per case, processed into two blocks (three cores each).
• Generation of multiple serial sections across at least three slides per block.

Main Results:

• A significant percentage of atypical (97%) and carcinomatous (25%) foci were small (<1mm, <5% of core tissue).
• Lesions were frequently missed on initial slides, with 13% of atypical foci and 3% of carcinomatous foci not present on the first slide.
• In all cases, the specific tissue containing the focus was not initially sectioned.

Conclusions:

• Current sampling methods may miss small but significant prostatic carcinoma foci.
• At least three slides are essential for comprehensive detection of prostatic carcinoma and atypical lesions on core needle biopsies.
• Optimized slide preparation protocols are critical for accurate prostate cancer diagnosis.