Human Papillomavirus-Associated Multiphenotypic Carcinoma: First Description of a Vulval Case.

Human papillomavirus (HPV)-associated multiphenotypic sinonasal carcinoma is a rare and recently described epithelial neoplasm exhibiting myoepithelial differentiation and morphological overlap with salivary gland neoplasms, especially adenoid cystic carcinoma; it is commonly associated with HPV, especially type 33. It has mainly been reported in the nasal cavity and paranasal sinuses with a single case reported in the breast. Herein, we report the first vulval example in a 47-year-old patient who presented with a large craggy mass in the region of the Bartholin gland. The histologic features were of a high-grade carcinoma composed of basaloid cells arranged in sheets and nests, with occasional ductal formations, surrounded by densely hyalinised basement membrane-type material. There was diffuse block-type immunoreactivity with p16 and HPV genotyping revealed high-risk HPV type 16. In reporting this case, we highlight the propensity for "salivary gland-type" neoplasms to arise in the vulva, especially in the Bartholin gland, and stress that pathologists should consider salivary-type neoplasms when faced with a morphologically unusual vulval tumor.