Dysplastic nevus syndrome refers to a cutaneous condition characterized by the presence of one or more atypical moles. An atypical mole is one which is larger than usual or abnormal in some other way. Also known as familial dysplastic nevi, this syndrome tends to run in some families where it is not uncommon to find that two or more family members display dysplastic nevi. Individuals with dysplastic nevus syndrome are believed to have an increased risk of developing melanoma.
Melanoma is a malignant tumor that can appear anywhere on the body and is considered the most serious of all skin cancers. A dysplastic nevus or atypical mole often grows as the result of exposure to sunlight and may become malignant. Individuals with a mole do not necessarily have skin cancer, but are at increased risk of developing skin cancer, particularly if the mole is atypical.
In some, familial melanoma may be caused by lifestyle choices or environmental factors. It may also be caused by genetic factors. Dysplastic nevus syndrome is not cancer, but it is often a precursor to skin cancer requiring regular monitoring and testing. When moles do become cancerous, they are defined as familial atypical multiple mole-melanoma syndrome or simply FAMMM syndrome.
Also known as B-K mole syndrome or atypical mole syndrome, dysplastic nevus syndrome is usually characterized by the presence of multiple atypical moles where the pigment of some of the moles appears to bleed into the skin. Not only are these moles generally larger than an average mole, but they also appear to be different in color, such as being pinkish tan or pinkish brown. These lesions tend to also appear primarily on parts of the body that are exposed to sunlight, but can also be present in areas that do not receive much sun exposure. While most people with dysplastic nevus syndrome have multiple atypical moles sometimes exceeding 200, some have only one.
Dysplastic nevus syndrome is diagnosed by a physician specializing in oncology who can usually tell by the mole’s appearance whether the syndrome is present or not. A doctor will also inquire about a patient’s family history to discover whether one or more relatives have been stricken with melanoma. Once dysplastic nevus syndrome is diagnosed, a doctor will biopsy the mole to determine whether it is malignant and photograph it to monitor the mole’s changes in asymmetry, diameter and color over time.