Interpretation of skin biopsies by general pathologists: diagnostic discrepancy rate measured by blinded review

Slide review has been advocated as a means to reduce diagnostic error in surgical pathology and is considered an important component of a total quality assurance program. Blinded review is an unbiased method of error detection, and this approach may be used to determine the diagnostic discrepancy rates in surgical pathology.

To determine the diagnostic discrepancy rate for skin biopsies reported by general pathologists.

Five hundred eighty-nine biopsies from 500 consecutive cases submitted by primary care physicians and reported by general pathologists were examined by rapid-screen, blinded review by 2 dermatopathologists, and the original diagnosis was compared with the review interpretation.

Agreement was observed in 551 (93.5%) of 589 biopsies. Blinded review of these skin biopsies by experienced dermatopathologists had a sensitivity of 100% (all lesions originally reported were detected during review). False-negative errors were the most common discrepancy, but false positives, threshold discrepancies, and differences in type or grade were also observed. Only 1.4% of biopsies had discrepancies that were of potential clinical importance.

Blinded review demonstrates that general pathologists reporting skin biopsies submitted by primary care physicians have a low diagnostic error rate. The method detects both false-negative and false-positive cases and identifies problematic areas that may be targeted in continuing education activities. Blinded review is a useful component of a dermatopathology quality improvement program.