A mole, known medically as a nevus, is a common non-cancerous skin growth formed when melanocytes, the pigment-producing cells, cluster together. Most people have between 10 and 40 moles by adulthood. Moles can appear anywhere on the skin, including the genital or pubic region, even areas rarely exposed to sunlight. While finding a spot in this private location can cause alarm, the vast majority of genital moles are entirely harmless.
Prevalence and Typical Appearance
Moles are found in the vulvar area of approximately 15% of women with lightly pigmented skin. Genital moles share characteristics with those elsewhere on the body, such as a stable appearance and a generally regular shape. Most benign nevi in this region are relatively small, typically measuring under 6 or 7 millimeters in diameter, with clear, well-defined borders.
A unique subtype known as atypical melanocytic nevi of the genital type (AGN) frequently appears, often in younger women. These specific nevi can be darker or have slight irregularities in their edges, leading to concern even though they are benign. They may appear as a flat spot (macule) or a slightly raised papule, often possessing uniform light to dark brown or black pigmentation. Hormonal shifts, such as during puberty or pregnancy, can also influence the appearance of existing moles.
Understanding the Risk Profile
The primary concern regarding any mole is the potential for it to develop into melanoma, the most aggressive form of skin cancer. While any mole on the body carries a small risk, melanoma can occur in areas that receive little or no sun exposure, including the genital area, as well as the anus and surrounding skin.
It is important to differentiate between cutaneous melanoma, which originates on the skin, and mucosal melanoma. Mucosal melanoma is a rarer, more aggressive form that develops on the moist lining (mucous membranes) of the body, such as the vulva or vagina. Accounting for only about 1.4% of all melanomas, it is often diagnosed at a later stage due to its hidden location. This delayed diagnosis contributes to the seriousness of cancer found in this region.
Unlike sun-exposed skin cancers, mucosal melanoma is not linked to ultraviolet radiation exposure. It can sometimes be amelanotic, meaning it lacks the dark pigment typically associated with moles, making it harder to spot. The benign atypical genital nevi are generally considered stable and do not progress to malignancy. Therefore, the overall risk is low, but the difficulty of routine self-examination can lead to a delayed finding of a problematic lesion.
Monitoring and When to Seek Professional Advice
Regular self-examination is the most effective tool for monitoring any pigmented lesion, even in less accessible areas like the genitals. This requires checking the area monthly, often using a mirror, to establish a baseline for what is normal. The standard guideline for checking moles is the ABCDE rule: Asymmetry, Border irregularity, Color variation, Diameter, and Evolution.
For genital moles, the “E” for Evolution—meaning any change in size, shape, or color—is the most important factor to track. This is because some benign genital nevi naturally violate other criteria, such as being darker (Color) or having an irregular shape (Border). A change in a stable mole, or the appearance of a new spot in adulthood, should prompt a professional evaluation.
Beyond the ABCDE guidelines, specific symptoms necessitate a prompt visit to a healthcare provider, such as a gynecologist or dermatologist. These signs include any mole that begins to bleed, itch, crust, or ulcerate without a known cause. Other concerning symptoms involve unexpected discharge, pain, or a new or growing lump or mass. Seeking an evaluation for any of these changes is the most prudent step.