Spiradenocylindrocarcinoma. Report of a case with a low-grade component of spiradenocarcinoma and an immunohistochemical study.

Spiradenocylindrocarcinoma is a very rare malignant cutaneous neoplasm of the folliculosebaceous-apocrine unit. We report a case of this hybrid tumor in a 42-year-old woman. The tumor consisted of 2 circumscribed nodules with areas of cylindrocarcinoma and low-grade spiradenocarcinoma. In the overlapping areas, both spiradenomatous and cylindromatous features were observed. Expansion of the tumor beyond the fibrous pseudocapsule into the adjacent tissue was present. Furthermore, tumor cells were demonstrating mild to moderate pleomorphism and an increased mitotic index. p53 and ki-67 were among the positive immunohistochemical markers. A relatively small number of tumor cells expressed estrogen receptors. The aim of this study was to investigate the nature of this rare tumor of the skin appendages.