What is a dysplastic nevus?

A dysplastic nevus, or atypical mole, is irregular in color and border, is larger than 5 mm in diameter, and often has an erythematous (red) background. In certain families, dysplastic nevi indicate an increased risk of developing a familial form of malignant melanoma. This is the Dysplastic Nevus Syndrome, also known as Familial Atypical Mole and Melanoma Syndrome. Affected members in these families invariably develop malignant melanoma. However, most individuals with a dysplastic nevus that do not have a family history of Dysplastic Nevus Syndrome, and will never develop malignant melanoma. The precise risk is uncertain.

With what can dysplastic nevus be confused?

Malignant melanoma is the main differential diagnosis.

How is dysplastic nevus diagnosed?

A dysplastic nevus is diagnosed clinically by your dermatologist. Your doctor will perform a biopsy to confirm the diagnosis. The dermatopatholgist will observe the cells of the dysplastic nevus under the microscope for any cellular or architectural atypia.

How is a dysplastic nevus treated?

Depending on how many lesions are present, excisional biopsy is the treatment of choice. When many nevi are present, at least two should be biopsied. The rest are followed closely with frequent dermatologist skin exams, total skin photography, patient education, and patent self-examination. The exact physician follow-up schedule depends on whether or not the patient has a family history of Dysplastic Nevus Syndrome, and for how long the patient has already been followed.

What is the prognosis for dysplastic nevus?

Virtually all patients with dysplastic nevi who have a family history of Dysplastic Nevus Syndrome will develop malignant melanoma. Close physican follow-up and excisional biopsies are required. However, most people without a family history of Dysplastic Nevus Syndrome will not develop a melanoma. Although melanoma can develop in a dysplastic nevus, it is more likely to develop de novo at another location. Patients with a large number of melanocytic nevi, whether or not dysplastic, have an increased risk of developing melanoma. Annual full body skin exams are advised.