Basal cell carcinoma with prominent central palisading of epithelial cells mimicking schwannoma.

Basal cell carcinoma (BCC), the most common malignant neoplasm of skin, may show a wide spectrum of histologic appearances. The presence of peripheral palisades is a very characteristic feature of BCC but, to our knowledge, central nuclear palisading has never been described. We report two cases of BCC exhibiting striking central nuclear palisading with Verocaylike bodies, in a pattern reminiscent of schwannoma. Peripheral palisades and clefts were also present in most tumor nodules and lobules, giving the neoplasms the overall configuration of otherwise typical solid BCC. In addition, foci of conventional BCC could be found adjacent, and in transition, to schwannoid areas. The immunohistochemical study showed strong reactivity for keratins (AE1 and AE3) in tumor cells, whereas no immunostaining for S-100 or muscle-specific actin was found. This previously undescribed histological feature of BCC should lead us to include BCC in the list of tumors to be considered in the differential diagnosis of a cutaneous neoplasm with schwannoid features.