RESUMO
CONTEXT: In our laboratory, for small skin biopsies or curetted specimens, 3 slides are prepared before the case is reviewed by the dermatopathologist. OBJECTIVE: To examine the utility of these "prospective" step sections in improving diagnostic accuracy and turnaround time. DESIGN: Five hundred consecutive cases, in which step sections had been cut prior to slide review, were studied. For each specimen, 3 slides, each consisting of 1 ribbon of tissue containing 4 to 6 sections, were obtained at 50-microm intervals from the paraffin block. RESULTS: Fifty-eight biopsies (12%) were nondiagnostic using slide 1 alone. Step sections provided a diagnosis in 19 of 58 cases. In an additional 15 cases (3%) in which a diagnosis was possible using slide 1, deeper levels resulted in a change in diagnosis. Thus, in 34 (7%) of 500 biopsies, deeper levels resulted in improved diagnostic accuracy. In addition, the pathologist would have ordered step sections in a further 117 cases (23%) to clarify the diagnosis rendered on level 1 or to exclude other lesions. Thus, 30% of small skin biopsies would have required deeper levels if step sections had not been obtained prior to slide review. CONCLUSIONS: In our laboratory, the use of prospective step sections is essentially cost-neutral and case turnaround time is improved by 9% to 45%. Step sections result in a changed diagnosis in 7% of small skin biopsy specimens.
