My Dermatologist Diagnosed Me With a Dysplastic Nevus, What Does That Mean?

By
Christopher Chu M.D.
on
February 19, 2024

If you’ve been diagnosed with a dysplastic nevus, also known as an atypical mole, you might have concerns about what this means for your health. The relationship of dysplastic nevi with melanoma is complex. Some dermatologist may call it pre-melanoma, while others will tell you not to worry. Even more confusing, many dermatologist have different recommendations for how to manage and treat dysplastic nevi. In this post, we’ll dive into what a dysplastic nevus is, and what being diagnosed with one may mean for your health.

The Diagnosis of Dysplastic Nevi

A dysplastic nevus is often diagnosed by a dermatopathologist, a pathologist who specializes in interpreting skin biopsy. The process starts when your dermatologists performs a biopsy of a suspicious mole during a routine skin check. The pathologist will examine the mole under a microscope, looking for atypical features that might be concerning for a melanoma. If there are some atypical features, but not enough to be considered diagnostic of a melanoma, the dermatopathologist may often call these moles a dysplastic nevus. These dysplastic nevi show a range of atypical features and are graded as mild, moderate, or severe based on the extent of these features.

 

A typical dysplastic nevus

Quantifying the Risk

While genetic studies have shown that dysplastic nevi are genetically between normal benign moles and melanoma, the progression of an individual dysplastic nevus to melanoma is very rare​​. In one large study, only 0.4% of severely atypical nevi developed into melanoma at the biopsy site. On the other hand, while the risk of individual dysplastic nevi developing into melanoma is rare, dysplastic nevi can act as a marker for your genetic risk for melanoma. Studies suggest that individuals with dysplastic nevi have a 3- to 20-fold increased risk of developing melanoma compared to those without​​. The risk escalates with the number of atypical nevi present: a single atypical nevus poses a relative risk of 1.5, while having five atypical nevi can increase the risk to 6.36 compared to having none​​.

 

So what do I do?

To add to the confusion, many dermatologist differ in their management approaches to dysplastic nevi. Some advocate for re-excising any nevus if the initial biopsy margins are positive, to prevent the so-called “pseudo-melanoma” phenomenon, where a nevus that grows back might be confused with melanoma​​, and to ensure the mole is completely removed in case the pathologist was unable to see atypical features in the part of the mole that was left in the body.

Other dermatologist may opt for a more conservative approach, especially when the nevus displays only mild atypia, as most dysplastic nevi do not evolve into melanoma and are considered variants of common nevi​​.

Most dermatologist will re-excise nevi with severe atypia given how closely these may resemble melanomas under the microscope.

 

The Bottom Line

While the term ‘pre-melanoma’ is used by some to describe dysplastic nevi, it’s important to understand that the vast majority of these moles will not progress to melanoma. Being diagnosed with an atypical nevus can sound scary, but ultimately, having a dysplastic nevus simply indicates you have a genetic predisposition for developing melanoma. Vigilance, sun protection, and regular skin checks with your board-certified dermatologist at Pure Dermatology remain your best tool to combatting your risk of melanoma and monitoring these atypical moles.