Sarcomatoid basal cell carcinoma.

We read with interest the recent paper by Fukunaya in this journal regarding a case of cutaneous spindle cell carcinoma following a basal cell carcinoma (BCC). The author comments on the presence of BCC elements in 8 of the 19 previously reported cases of cutaneous metaplastic carcinoma (‘‘carcinosarcoma or sarcomatoid carcinoma’’). We completely agree with the case that he described. We call attention to the omission of 2 additional cases, recently reported by our group. The first report, published in 1998, describes an 82-yearold male with a 2.5-cm cutaneous lesion arising on the supraclavicular area; the second case, published in 2003, reports on a 64-year-old male presenting a 1.2-cm lesion on the right ear. Both lesions showed an exophytic and ulcerated clinical appearance and a fast growth before surgery. The histologic study revealed a mixture of a typical BCC and a sarcomatoid neoplasm with spindle cells in a storiform pattern (case 1) and embedded in a myxoid stroma (case 2). Despite the sarcomatoid component seemingly developed from the BCC, epithelial differentiation with positive cytokeratin (AE1/AE3) could only be demonstrated in the second case. However, immunohistochemistry disclosed positive p53 immunostain in both cellular components of both cases, supporting a common pathway of both the epithelial and sarcomatoid elements. Moreover, Yada et al recently investigated the expression of CD10 in BCC with 86% of the tumors studied showing positive stain for this antigen. In line with these results, the authors suggested a possible role of CD10 overexpression in stromal cells as a marker of tumor invasiveness. In our 2 cases, the positive CD10 stain in both tumoral components allowed us to explain the aggressive behavior of the lesions. In summary, in view of these findings and in an attempt to avoid confusing nomenclature we consider the use of ‘‘sarcomatoid basal cell carcinoma’’ as the most appropriate term for these uncommon tumors.