Human Papillomavirus–Negative Spindle Cell Carcinoma of the Vulva Associated With Lichen Sclerosus

Although spindle cell carcinoma (SC) is a common neoplasm in the oral cavity, upper respiratory tract, and other head and neck areas, its occurrence in the vulva is rare. We report a case of this rare condition with immunohistochemical, ultrastructural, and human papillomavirus (HPV) testing. The neoplastic cells were positive for vimentin, keratins (AE1-AE3, keratin 902, and keratin 903), and epithelial membrane antigen. Ultrastructurally, they showed primitive junctions and tonofilaments. HPV testing by polymerase chain reaction was negative. In addition, we review the clinicopathologic findings of the four well-documented cases of vulvar SC that have been reported previously in the English language literature.