What is a Dysplastic Mole?

A benign mole with an irregular shape, a dysplastic mole looks similar to melanoma, an often deadly form of skin cancer. Also known as atypical moles, dysplastic nevi and dysplastic nevus, these moles can indicate a higher risk of melanoma. Though skin cancer will not necessarily develop from a dysplastic mole, the more of these growths and individual has, the higher the risk that person will have of developing melanoma from either a mole or normal skin.

Dysplastic moles tend to have irregular, weakly defined borders. They are larger than regular moles and vary greatly in color. Some dysplastic moles have notches and many will thin at the edges so that part of the mole is at the same level as the skin. Though they can appear anywhere on the body, dysplastic moles usually appear on the calves in women and on the trunk in men.

The development of dysplastic moles is often due to heredity. Chances of developing melanoma can also be heavily affected by a family history of the disease. Individuals with multiple close blood relatives who have had melanoma are typically advised to perform monthly self-exams in order to determine if new moles have developed. In many cases, people at high risk of developing melanoma are also advised to have regular professional skin examinations so that potentially dangerous growths can be caught before they turn deadly. Eye examinations can also be valuable for high-risk individuals, due to the risk of developing ocular melanoma.

Approximately half of the people who have melanoma have developed dysplastic moles at some time. Fair-skinned or heavily freckled individuals are at highest risk of developing this variety of mole. People with fair skin or who have a family history of melanoma are typically advised to take extra care with sun protection in order to ward off development of the moles.

A dysplastic mole is generally believed to be pre-cancerous, though many people who have them never develop melanoma. In most cases, a proliferation of these kinds of moles will indicate a higher risk of an individual having melanoma, though the moles themselves will not develop the cancer. For this reason, dysplastic moles are usually not removed, because the melanomas tend to develop more often on normal skin, in a process known as developing de novo.

Doctors often use extensive, annually updated body photographs in order keep track of potential dysplastic mole growth in high-risk patients. If a mole has grown or changed in shape or color, the patient will usually undergo a biopsy so that the doctor can determine whether or not the mole is cancerous. The procedure involves the collection of skin tissue while the patient is under local anesthesia, which is then examined under a microscope.