Vaginal intraepithelial neoplasia

Vaginal intraepithelial neoplasia (VAIN) is a condition that describes premalignant histological findings in the vagina characterized by dysplastic changes.^[1]

Vaginal intraepithelial neoplasia
Specialty	Oncology

The disorder is rare and generally has no symptoms.^[2] VAIN can be detected by the presence of abnormal cells in a Papanicolaou test (Pap smear).^[2]

Like cervical intraepithelial neoplasia, VAIN comes in three stages, VAIN 1, 2, and 3.^[3] In VAIN 1, a third of the thickness of the cells in the vaginal skin are abnormal, while in VAIN 3, the full thickness is affected.^[3] VAIN 3 is also known as carcinoma in-situ, or stage 0 vaginal cancer.^[3]

Infection with certain types of the human papillomavirus ("high-risk types") may be associated with up to 80% of cases of VAIN.^[4] Vaccinating with HPV vaccine before initial sexual contact has been shown to reduce incidence of VAIN.^[5]