Vulvar intraepithelial neoplasia (VIN) most commonly appears as raised white, red, pink, or dark-colored patches on the vulvar skin. These patches can vary widely in size, shape, and texture, which is part of what makes VIN tricky to identify. The appearance also depends on which type of VIN is present, since the two main types look quite different from each other.
The Most Common Appearances
VIN lesions generally show up as flat or slightly raised patches (called plaques) on the vulvar skin. The three most common presentations are a thick white plaque, a thin pink-red plaque, and a red glazed patch that looks smooth and shiny. Beyond these, lesions can also appear gray, tan, brown, or black. Some people have lesions that combine several colors at once, such as a flat pink center with a raised white border.
The texture varies just as much as the color. Some lesions have a smooth surface, while others look rough, bumpy, or wart-like. Certain lesions develop a gravel-like texture or a mosaic pattern of fine lines across the surface. Thicker lesions may have a crusty or scaly top layer caused by excess keratin, the same protein that makes up your outer skin.
HPV-Related vs. Non-HPV Types
The two main types of VIN look and behave differently, which matters for understanding what you might see.
HPV-related VIN (sometimes called usual-type or uVIN) tends to appear as multiple separate lesions rather than a single spot. These are typically raised and found around the vaginal opening and the outer lips of the vulva. Because they’re often multifocal, you might notice patches in more than one area at the same time. They can be white, gray, red, pink, brown, or black, and sometimes show fine dotted or mosaic-like vascular patterns on their surface.
Non-HPV VIN (called differentiated VIN, or dVIN) is much harder to spot. It usually shows up as a single, poorly defined pink or white plaque that can easily be mistaken for a benign skin condition. It often develops alongside chronic inflammatory conditions like lichen sclerosus, a disorder that itself causes white, thinning patches on the vulva. Because dVIN blends in with these background changes, it’s frequently missed or misdiagnosed as a harmless skin problem. This is concerning because dVIN, despite being less common, is actually linked to a more aggressive path toward vulvar cancer.
What Symptoms Accompany the Visible Changes
Most people with VIN do experience symptoms alongside the visible lesion. Persistent itching is the most frequently reported complaint, sometimes accompanied by burning or soreness. The affected skin may feel thicker or rougher than surrounding tissue. In rare cases, there are no symptoms at all initially, and the lesion is found during a routine exam or while being evaluated for something else. This is one reason why any unexplained change in the appearance of vulvar skin deserves attention, even if it doesn’t hurt or itch.
How VIN Is Distinguished From Similar Conditions
Several common vulvar conditions can look like VIN to the untrained eye. Lichen sclerosus produces white, thinning patches that overlap visually with VIN’s white plaques. Psoriasis, eczema, and even genital warts can create raised, discolored, or textured patches in the same area. Differentiated VIN in particular is difficult to distinguish from benign skin conditions based on appearance alone.
This is why a biopsy, where a small sample of tissue is removed and examined under a microscope, is the only way to confirm VIN. No amount of visual inspection can definitively diagnose it. If your provider notices a suspicious patch during an exam, they may apply a dilute acetic acid solution (similar to vinegar) to the skin. Abnormal cells tend to turn white temporarily under this solution. This test is highly sensitive, catching about 97% of high-grade VIN cases, but it also produces many false positives (only about 40% of patches that turn white actually turn out to be VIN). Its main value is in mapping the borders of a known lesion and in ruling VIN out: if nothing turns white, there’s a 98% chance no high-grade lesion is present.
Where Lesions Typically Appear
HPV-related VIN favors the areas around the vaginal opening (the introitus) and the outer labia. Lesions can appear on one side or both, and because this type is often multifocal, patches may show up in several spots at once, sometimes extending to the skin around the anus or the area between the vagina and anus (the perineum).
Differentiated VIN tends to be a single lesion. It often arises in areas already affected by lichen sclerosus or another chronic skin condition, which can be anywhere on the vulva but commonly involves the inner labia, clitoral hood, or perineum. The lesion may sit within a broader area of white, scarred-looking skin, making it even harder to pick out.
What to Watch For on Your Own Skin
Because VIN has no single defining look, the most useful thing to watch for is any persistent change. A patch of vulvar skin that has turned a different color, become raised or thickened, developed a rough or wart-like texture, or simply won’t go away over several weeks is worth having examined. The same applies to any sore or raw-looking area that doesn’t heal. These changes can be subtle, especially in differentiated VIN, so paying attention to your baseline is key. If you already have a diagnosed condition like lichen sclerosus, be particularly attentive to any new spot or texture change within the affected area, since this is where dVIN is most likely to develop.