Vulvar dysplasia is abnormal cell growth on the vulva that isn’t cancer but can develop into it if left untreated. Doctors formally call it vulvar intraepithelial neoplasia (VIN), and it refers specifically to high-grade precancerous changes in the skin cells of the vulva. About 6% of treated cases eventually progress to invasive cancer, making early detection and treatment important.
The Two Types of Vulvar Dysplasia
There are two distinct types, and they differ in cause, who they affect, and how they behave.
The first and most common is called “usual type” VIN, which accounts for more than 80% of cases. It’s driven by human papillomavirus (HPV) infection. When researchers test these lesions, about 93% are HPV-positive, with HPV 16 being the most common strain found in roughly 44% of cases. This type tends to appear in younger women and often has a warty or raised appearance.
The second type is “differentiated” VIN. This form is not caused by HPV. Instead, it typically develops on a background of lichen sclerosus, a chronic inflammatory skin condition of the vulva. It usually appears as thickened, scaly skin. The average age at diagnosis ranges from 67 to 78 years, though cases have been documented in women as young as 17. Despite being less common overall, differentiated VIN accounts for a disproportionate share of vulvar cancers, making it the more aggressive of the two types.
Symptoms to Recognize
Vulvar dysplasia doesn’t always cause noticeable symptoms, which is one reason it can go undetected. When symptoms do appear, the most common is persistent itching of the vulvar skin that doesn’t resolve on its own. Other signs include a lump or wartlike bump, an open sore that doesn’t heal, pain or tenderness, and visible skin changes like unusual coloring or thickening of the tissue. Some women notice bleeding from the area that isn’t related to their period.
None of these symptoms are unique to dysplasia. They overlap with many other vulvar conditions, which is why a biopsy is the only way to confirm the diagnosis.
What Increases Your Risk
HPV infection is the primary driver for the usual type, and several factors raise your chances of developing persistent HPV-related changes. Smoking is one of the strongest. Current smokers face more than three times the risk of vulvar squamous cell cancer compared to nonsmokers. Former smokers, notably, don’t appear to carry much increased risk, suggesting that quitting makes a real difference.
A weakened immune system also plays a significant role. Women with HIV have a substantially higher risk of vulvar and cervical cancer. Those on immunosuppressive medications (after organ transplant, for example) are nine times more likely to develop an HPV infection and face dramatically higher cancer risks overall. Having a first-degree relative with anogenital cancer may also increase susceptibility.
How It’s Diagnosed
Diagnosis starts with a visual exam. Your doctor may use a colposcope, a magnifying instrument that allows a close-up view of the vulvar skin. During this exam, a dilute vinegar solution is sometimes applied to the area, which causes abnormal tissue to turn white and stand out against healthy skin. The vinegar may cause a brief burning sensation but isn’t painful.
If any area looks suspicious, a punch biopsy is taken. This involves removing a small circular piece of tissue using a specialized tool, typically in a single quick motion. The sample is then examined under a microscope to determine whether the cells are precancerous and, if so, what type of VIN is present. A biopsy is essential because visual appearance alone can’t reliably distinguish dysplasia from other conditions or determine its severity.
Treatment Options
Treatment aims to remove or destroy the abnormal cells before they have a chance to become cancerous. The two main approaches are surgical excision (cutting out the affected tissue) and topical therapy with a cream that stimulates the immune system to attack abnormal cells. Laser therapy, which uses focused light to vaporize the lesion, is another option.
Topical treatment typically involves applying a 5% cream up to three times per week for a maximum of 16 weeks, with the frequency gradually increased as tolerated. For surgical excision, the procedure removes the visible lesion along with a small margin of normal tissue.
Research comparing these approaches shows they perform similarly. In one study, 52% of patients treated with the topical cream and 56% treated with laser therapy experienced treatment failure over the follow-up period. The difference was not statistically significant. Excision and topical treatment also show comparable outcomes, with recurrence rates of about 35% for excision and 41% for topical therapy. The choice between them often depends on the size and location of the lesion, how many areas are affected, and patient preference. Excision has the advantage of providing a tissue sample that can be examined for any hidden invasive cancer.
Recurrence Is Common
One of the most important things to understand about vulvar dysplasia is that it comes back frequently, regardless of how it’s treated. In a large study of 411 patients, about 30% experienced a recurrence more than a year after their initial treatment. The median time to recurrence was roughly 7 to 11 months depending on the treatment method.
This high recurrence rate means long-term monitoring is essential. After treatment, you’ll need regular follow-up exams so any returning abnormal cells can be caught early. The underlying risk factors, particularly HPV infection or lichen sclerosus, often persist even after the visible lesion is gone, which explains why the condition tends to recur.
Progression to Cancer
The central concern with vulvar dysplasia is its potential to become invasive vulvar cancer. Among treated patients, about 5.8% progress to invasive disease. Without treatment, the risk is higher, though exact numbers are difficult to study because most women receive some form of intervention once diagnosed.
Differentiated VIN carries a greater progression risk than the usual (HPV-related) type, despite being less common overall. This is one reason accurate typing through biopsy matters. Knowing which type you have helps guide how aggressively it should be treated and how closely you need to be followed afterward.
HPV Vaccination and Prevention
Because the majority of vulvar dysplasia cases are HPV-related, vaccination against HPV is the most effective preventive measure. The vaccine covers HPV 16, the strain found most often in these lesions. Quitting smoking, if applicable, is another meaningful step given the more than threefold increase in risk among current smokers. For women with lichen sclerosus, managing that condition with your doctor may help reduce the risk of the differentiated type developing over time.