A dysplastic nevi is an irregular mole. We all have many different types of moles in our body and many times dermatologists biopsy these moles that look a little bit abnormal and have a different shape or different configuration. Primarily we are looking for the rules of melanoma or the A, B, C, D’s:
- A: Mole is asymmetrical
- B: The borders are irregular
- C: The color is irregular.
- D: The diameter is usually greater than six millimeters or a mole that is evolving or changing.
When dermatologists spot these moles, they typically recommend a biopsy. Usually, that biopsy will come back as a dysplastic nevi of mild, moderate or severe atypia. Now, what does that mean and why do dermatologists recommend removing them?
First of all, if you take a look at skin in general, you have the epidermis and melanocytes that are in the epidermis. These melanocytes can give rise to melanoma. Melanoma is the worst of all skin cancers and they can spread all over your body. Therefore, you want to avoid them.
A dysplastic nevi arises from the same types of cells, melanocytes, that look irregular under the microscope. We want to reduce the risk of this becoming a melanoma. Dysplastic nevi is not a a cancerous mole, skin cancer and is not a melanoma.
However, in many studies that have been done looking at the risk factors for the development of melanoma, it has been found that a dysplastic nevi does carry a 16% risk of potentially developing into a melanoma. Therefore, we typically recommend excising it or removing any residual margins or cells that are still attached to the skin to reduce the risk of any melanoma.
Microscopically, these cells look abnormal. Just because there is an increased risk doesn’t necessarily mean that you are going to develop a melanoma. But the standard of care is to excise these lesions and to reduce the risk of it becoming a melanoma.
In many cases, when you look at it under the microscope, if a mole is mildly atypical, sometimes that is a fairly good side. In other cases where there is severe atypia, which means a severe irregularity where the cells look very abnormal under the microscope, then that starts looking more like a melanoma and in many cases should be excised with several margins around the biopsy site.
In summary, a dysplastic nevi is an irregular mole, that should be properly excised to reduce the risk of melanoma. It is not a cancer. It is not a melanoma. But the standard of care in Florida is to remove the moles surgically to reduce that risk.
An analogy that I like to give to my patients is like driving a car. In many cases, if you get into a car, you are not going to have a car accident or die in a car accident, but there is always that possibility. There is a risk that when you drive a car, a car accident can happen and you can undergo a fatality.
As you drive faster, or if you are drinking or texting while driving, the risk of a fatality increases. That doesn’t mean that it is going to happen, but sometimes it does. Statistically, there is a higher risk of an injury occurring if you do those things. So to reduce the risk of a fatality, we lower the speed limit, we don’t text or drink and drive. Consequently, our risk is reduced.
And similarly, when we have a dysplastic nevi, it doesn’t mean a melanoma is going to happen, but the standard of care is to excise it to reduce the risk of a melanoma