Primary cutaneous carcinosarcoma: The first reported case with peripheral nerve sheath differentiation

Abstract

Primary cutaneous carcinosarcomas (CS) are extremely rare biphasic tumors mainly located on sun-exposed areas of the body. Two hypotheses-multiclonal (convergence) and monoclonal (divergence)-have been suggested for the evolution of these tumors. According to multiclonal hypothesis two or more stem cells of epithelial and mesenchymal origin give rise to these tumors, while a single totipotential cell differentiate into epithelial and mesenchymal components, either synchronously or metachronously according to monoclonal hypothesis. Cutaneous CSs are subdivided into two distinct groups as epidermal and adnexal CSs, due to their epithelial content. We present an interesting case of cutaneous adnexal CS, showing peripheral nerve sheath differentiation and having the spiradenocarcinoma component derived from spiradenoma. To the best of our knowledge, it is the first reported case of CS with these features in the literature.