Cutaneous basal cell carcinosarcoma: case report and literature review

Carcinosarcomas are malignant neoplasms with biphasic carcinomatous and sarcomatous or sarcoma‐like components. In general, the sarcomatous component is accepted to be the result of divergent mesenchymal differentiation of the epithelial component. Although well characterized in some anatomic locations (e.g. uterus, upper aerodigestive tract and lung), carcinosarcomas of the skin are rare. Reported epithelial components include squamous, adnexal, neuroendocrine and basaloid. Including this case, only 47 cases of primary cutaneous basal cell carcinosarcoma have been reported in the literature to date. We performed an extensive immunophenotypic evaluation in our case, which confirmed the previously reported coexpression of p53 in both components, and revealed a hitherto unreported coexpression of p16 and p63. Additionally, this report reviews the clinical, pathologic, immunophenotypic characteristics and outcomes of the basal cell carcinosarcomas reported in the literature, in order to emphasize the overall uniform characteristics and clinical behavior of this neoplasm.