VIN can look like raised bumps, flat spots, or patches of discolored skin. Visible symptoms may vary depending on the type you have. In some cases, VIN may not cause noticeable symptoms at all.

Vulvar intraepithelial neoplasia or VIN is a growth of abnormal cells on the vulva. Lesions can appear anywhere on the vulva, including the labia, the entrance to the vagina, and the clitoral area.

Not all visual changes are caused by VIN. Dark patches and spots that look like VIN can be caused by other conditions, like acanthosis nigricans, vulvar eczema, and skin tags.

Nevertheless, it’s best to be cautious. It’s a good idea to have any suspicious lumps, bumps, and patches examined by a medical professional, especially if they develop on or near your vulva.

Although VIN isn’t cancerous itself, it can progress to cancer over time. Regular check-ups and early treatment may help prevent it from developing into cancer.

VIN-related bumps may:

  • be raised or flat
  • be a different color than the skin around them
  • look like moles or freckles
  • change in size, shape, border, or color over time

The condition can also cause discoloration. You might notice patches of skin that are:

  • white
  • gray
  • red
  • brown
  • black

These patches may have a different texture than the surrounding area.

According to the American College of Obstetricians and Gynecologists, VIN can vary in appearance depending on the type you have.

The two main types of VIN are:

  • Usual VIN (uVIN): Also called classic VIN, this is the most common type. It includes low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL).
  • Differentiated VIN (dVIN): dVIN is less common than uVIN. It’s more common in older adults than in younger people.

Usual VIN typically involves raised lesions — although it’s possible to have flat uVIN lesions, too. Often, uVIN lesions affect the labia majora (outer lips) and the area around the vaginal opening.

Differentiated VIN lesions usually look like patches of thick or discolored skin. It’s associated with lichen sclerosis and lichen planus. So if you have a rash or bumps that look like either condition, especially on your vulva, it’s a good idea to consult a healthcare professional.

VIN can also cause:

If you have one or more VIN symptoms, it’s a good idea to make a medical appointment.

Research has shown that about half of dVIN cases and about 9.7% of uVIN cases turn into cancer within 10 years of diagnosis.

Because of this, VIN needs to be monitored by a healthcare professional. If necessary, your doctor may treat it immediately.

Even if you don’t have VIN, it’s best to see a professional as soon as possible, as you may have another condition that needs treatment.

Not all visual changes to the vulva are caused by VIN. It’s possible that another condition is causing your symptoms.

Lesions on the vulva, for example, may be caused by vestibulitis, candidiasis, or herpes infections.

To the untrained eye, VIN may also look like another condition, such as:

VIN can look like raised bumps, discolored patches of skin, or freckle-like marks. The appearance of VIN lesions can vary depending on the type of VIN you have. In some cases, VIN may not have any visible symptoms.

VIN isn’t cancerous in itself, but it can develop into cancer. It’s important to consult with a healthcare professional sooner rather than later if you notice any changes to your vulva.

Monitoring and early treatment can improve your outlook.

Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.