Vulvar intraepithelial neoplasia - Anogenital in
The most common form is usual type VIN, which is associated with infection by HPV. The other (and less common) form is differentiated VIN, which is associated with dermatologic conditions of the vulva, especially lichen sclerosus. Differentiated VIN is more likely to be associated with vulvar squamous cell carcinoma and is more likely to recur.
Usual type VIN is becoming more common, especially among women in the fifth decade of life. Risk factors for usual type VIN include HPV infection, tobacco use, and immunocompromised state (same risk factors as high-grade cervical dysplasia). Differentiated VIN is more common in postmenopausal women with vulvar dermatoses, especially if left untreated.
Patients with VIN may present with a vulvar lesion detected by themselves or a partner. In patients who present with a complaint, vulvar pruritus is the most common. Less commonly seen are complaints of pain (eg, with urination or intercourse) or burning. Nearly half of patients diagnosed with VIN are asymptomatic. In these cases, the lesion is first identified during a physical exam.
N90.3 – Dysplasia of vulva, unspecified
399933001 – Vulval intraepithelial neoplasia (VIN)
Differential Diagnosis & Pitfalls
- Lichen sclerosus – A chronic dermatologic condition of the vulva characterized by pain and itching. Associated with thinning and whitening of the skin surrounding the vulva and anus. Responds to topical corticosteroids.
- Lichen planus – A chronic dermatologic condition that can affect the vulva, mouth, and other parts of the body. Like lichen sclerosus and VIN, it is associated with pain and itching, but usually has a more violaceous hue. A characteristic feature is "Wickham striae" – faint white lines that course across the lesion. Ulcerations are commonly found with this condition as well.
- Condyloma – Not always easily distinguishable from VIN without biopsy.