Utility of deeper sections and special stains for dermatopathology specimens.

Special (non-hematoxylin and eosin) stains and deeper sections are routinely used in dermathopathology, although their utility has not been well established. All cases requiring special stains or deeper sections over a three-month period were reviewed to see how often these additional studies contributed to accurate diagnosis. In our series, deeper sections provided diagnostic information to the pathologist in 37.3% [95% confidence interval (CI) 28-46%] of the cases in which they were performed. Deeper sections are more likely to provide a more accurate diagnosis (23.6%, 95% CI 16-32%) rather than establish a new diagnosis not seen on the original sections (13.6%, 95% CI 7-20%). Their use is especially helpful in assessing the presence or absence of cutaneous malignancy rather than in diagnosing inflammatory skin processes. Special stains contributed to the diagnosis in 21.1% (95% CI 11-32%) of cases. When special stains were performed to diagnose an infection they were effective in 14.7% (95% CI 6-24%) of the cases. When special stains were performed to diagnose any other pathologic processes (neoplasm, inflammation, collagen vascular disease, and amyloid) they were effective in 31.8% (95% CI 24-44%) of the cases.