A novel group of HPV-related adenocarcinomas of the lower anogenital tract (vagina, vulva, and anorectum) in women and men resembling HPV-related endocervical adenocarcinomas.

Human papillomavirus (HPV) is an oncogenic virus associated with the development of several human cancers. Primary vaginal, vulvar, and anal adenocarcinomas are rare and, to date, have rarely been shown to be associated with HPV infection. We report a series of nine HPV-related adenocarcinomas of the lower anogenital tract distal to the cervix. The tumors involved the vagina (4), anorectum (3), and vulva (2). Two of the three anorectal cases involved men. Patients presented with a vulvar or vaginal mass/nodule, painless rectal bleeding, or during screening colonoscopy. Lesions ranged in size from 3.2 to 8.4 cm. The most salient morphologic characteristic was the presence of papillary or villiform/villoglandular architecture in all cases. Tumors displayed features similar to those of usual type high-risk HPV-related endocervical adenocarcinoma, namely, mucinous or mucin-poor (pseudoendometrioid) features or a hybrid of these, with columnar cells with crowded, cigar-shaped to ovoid irregular nuclei. Mitoses (mostly apical) and apoptotic bodies were easily identified. Adenosis was present in two vaginal cases. One anal tumor featured abundant intracytoplasmic mucin that was multivacuolated in some areas imparting a "clear cell"-like appearance. All tumors were diffusely and strongly positive for p16. Seven of seven tested cases were positive for high-risk HPV by in situ hybridization or polymerase chain reaction. Follow-up information, available in five patients, revealed two local recurrences but no tumor related deaths or distant metastases. We report the first well-documented series of HPV-associated primary adenocarcinomas of the vagina, vulva, and anorectum and broaden the spectrum of HPV-related neoplasia involving the lower anogenital tract in both women and men.