A dermatologist may sometimes take a sample of a skin mole for a biopsy because of its unusual features, a patient’s symptoms or health history. Fortunately, most moles are not melanoma (a type of skin cancer). However, patients are commonly told they have an atypical mole, or atypical nevus, after a biopsy.

The good news is that atypical moles are noncancerous (benign).  However, there is a theoretical risk of these moles evolving into a melanoma (cancerous mole) down the road. That’s why some dermatologists may consider them “pre-cancerous.” The actual risk of an individual atypical nevus, or mole, developing into melanoma is thought to be low, but is unknown because oftentimes atypical moles are completely removed.

So if an atypical mole isn’t cancerous now, but there’s a chance it eventually could be, is it worth removing?

First, it helps to understand what an atypical mole is.

What is an Atypical Mole?

Atypical moles are “graded” based on their cellular features observed under a microscope by a dermatopathologist. A dermatopathologist subspecializes in pathology of the skin and can visually categorize the degree of disorganization seen within the cells that make up the mole. Grading of atypia is often reported as mild, moderate or severe.

Generally, mild atypical moles are thought to be relatively low risk. Usually these moles are observed for recurrence. If they regrow after being incompletely removed, or become symptomatic, a small safety margin around the pigment/scar may be surgically removed and rechecked.

Moles classified as moderate are often surgically removed and those classified as severe are almost always removed. Even though atypical moles are noncancerous, the more severe the atypia, the more it resembles melanoma. Potentially, it could become melanoma later in life. Or it could be confused with melanoma in a future biopsy (because atypical cells mixed with scar tissue from a biopsy can mimic melanoma).

Should it be Removed?

The bottom line is that there is no “correct” way to manage atypical moles. Each patient is different so managing moles depends on their situation.  For example, in patients with hundreds of moles, a large number of them may be atypical and it may not be practical to remove every mole with unusual features. As another example, those with a family history of melanoma and a few unusual moles may benefit from complete surgical removal of their atypical moles.

While there is no right answer that applies to every patient, it is important to do regular self skin exams and to point out new or changing moles to your board-certified dermatologist. The important thing to keep in mind is that atypical moles are noncancerous, and removing those with moderate and severe atypia reported on a biopsy may be recommended as a precautionary measure.