Malignant spiradenoma/cylindroma of the vulva.

Malignant spiradenoma/cylindroma of the vulva is an extremely rare adnexal tumor. We report the clinicopathological features of a 58-year-old woman who presented with malignant spiradenoma/cylindroma originating in the vulva and metastasized to the inguinal lymph nodes. Surgical excision with adequate margins and lymph node dissection was performed. Sections from the case were stained with Periodic Acid Schiff stain before and after diastase. Immunohistochemical study of the case using antibodies to carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), cytokeratin5/6 (CK 5/6), p63, cytokeratin7 (CK 7), smooth muscle actin (SMA), and S100 were performed. Microscopic examination revealed that spiradenoma nodules were positive to EMA and CEA. However, the cylindroma lobules showed strong immunoreactivity to p63 and CK5/6, whereas both tumor components were negative to S100, SMA, and CK7. Malignant spiradenoma/cylindroma is a rare tumor with controversial histogenesis that should be considered in the differential diagnosis of primary adnexal carcinoma and secondary metastatic tumors in the vulva. Further studies on a wider cohort should be encouraged.