Basal cell carcinoma with prominent central palisading of epithelial cellsmimicking 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, c entral 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 we re 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 muscl e-specific actin was found. This previously undescribed histological featur e of BCC should lead us to include BCC in the List of tumors to be consider ed in the differential diagnosis of a cutaneous neoplasm with schwannoid fe atures.