BASAL-CELL CARCINOMA - CYTOLOGIC AND IMMUNOCYTOCHEMICAL FINDINGS IN FINE-NEEDLE ASPIRATES

The smears of fine-needle aspirates corresponding to 137 histologicall y proven basal-cell carcinomas (BCCs) were reviewed. Satisfactory for evaluation were 127 smears; the remaining 10 were unsatisfactory. In 1 24 cases (97.6%), the cytologic diagnoses coincided with the histologi c ones. The remaining 3 were false negatives, and the subsequent histo logic correlation demonstrated superficial BCC missed by the needle. T he cytologic criteria that permitted a diagnosis of BCC were: variable -sized and irregular-shaped cohesive epithelial clusters, round to ova l monomorphic nuclei, bland chromatin pattern, and sparse cytoplasm. I n 35 cases, a panel of antibodies was used in the smears and in the re spective histologic sections. Epithelial clusters of BCC showed an int ense and diffuse positivity for AE-3 and BerEP4, while UEAI and AE-1 w ere negative. Although HMB45 and S100-A tested negative in the epithel ial clusters, a faint and sparse focal positivity for HMB45 and S-100A was seen in some clusters. This positivity is believed to correspond to just a few normal melanocytes and Langerhans cells trapped in the n eoplastic epithelial clusters. In the histologic correlates, the same results were obtained although HMB45 positivity was more conspicuous a t the periphery of the neoplastic nests. (C) 1998 Wiley-Liss, Inc.