Primary HPV-Associated Enteric-Type Adenocarcinoma of Vagina: A Case Report.

Primary enteric type adenocarcinomas of the vagina are extremely rare. We present a 63-year-old woman who had a polypoid mass localized to the distal vagina. The lesion was composed of a columnar glandular cell proliferation with focal cribriforming, reminiscent of tubular adenoma. Immunohistochemical stains were notable for expression of enteric markers (CDX2 and KRT20), as well as negativity for Mullerian markers (PAX8, ER, and PR), diffuse expression for p16, and positivity for high-risk HPV mRNA expression. Ultimately, a diagnosis of vaginal primary HPV-associated enteric type adenocarcinoma was rendered for this unusual lesion. To our knowledge, no prior cases of HPV-associated enteric type adenocarcinomas of the vagina have been described before.