Vulvar intraepithelial neoplasia (VIN)

Classification

Two Pathways

• Nomenclature: HPV-dependent VIN is now referred to as vulvar HSIL or uVIN.
• uVIN characteristics: It affects younger women, is often multifocal, and is associated with smoking and immunosuppression.
• uVIN immunohistochemistry: Immunohistochemically, it is p16-positive as an expression of HPV transformation.
• HPV-independent form: The HPV-independent form is called differentiated VIN or dVIN.
• dVIN characteristics: It usually develops on a background of lichen sclerosus in older women and is mostly unifocal.
• dVIN immunohistochemistry: It is often p53-aberrant and p16-negative.

Why the Distinction Matters

• Diagnostics: It is also more difficult to recognise because it appears histologically mature and atypia is confined to the basal layer.

Clinical features

Clinical Presentation and Diagnosis

• Clinical picture: Clinically, VIN presents as a white, reddish, or pigmented lesion, raised or flat, often with pruritus.
• Confirming the diagnosis: The diagnosis is established by biopsy, or mapping with multiple punch biopsies in case of multifocal findings.
• Additional workup: An additional workup is mandatory for the vagina, cervix, and anal canal, as HPV-associated neoplasia can be multicentric.

Keep learning in the app

Further reading (selection)

1. StatPearls: Vulvar Intraepithelial Neoplasia (NCBI Bookshelf)
2. DocCheck Flexikon, Vulväre intraepitheliale Neoplasie

Cross-references