Nevus (nevi for plural)
Nevus is an abnormal patch of skin that children may be born with or develop as they get older. A nevus is usually tan colored and may be flat or raised. It comes in various types, shapes and sizes and can occur on any surface of the skin or in the mucous membranes (the lining inside a child’s nose, mouth and lungs that produce mucous to keep them moist).
Nevus is usually benign but can degenerate into skin cancer (melanoma).
Causes & Risk Factors
Nevus is a collection of melanocytes (skin cells that produce melanin) within the top layers of the skin.
Nevus can be congenital, which means it is present at birth. It may change in size throughout life and some disappear with age (usually Mongolian spots).
Some nevi are associated with genetic disorders, like dysplastic nevus syndrome which can lead to melanoma. Others are passed down from generation to generation; this is known as epidermal nevus syndrome.
Acquired nevus is usually caused by sun exposure and is more common in people with lighter skin. It may change in size as a child gets older and comes in a wide variety of sizes, colors and shapes. These kinds of nevus tend to shrink as the child ages.
Symptoms & Types
Most nevi don’t have any other symptoms and are usually well tolerated by children. Some, depending on the type, size and location, can lead to itching, bleeding, pain, ulceration and disfigurement.
Some types of nevus can be associated with genetic syndromes, malignant degeneration and symptoms in other parts of the body, like seizures.
Nevus can be mistaken for skin cancer. In addition, it’s important to note that melanoma (the most dangerous form of skin cancer) can develop from existing nevi. Your child’s doctor can distinguish between nevus and skin cancer. Parents can remember the ABCDE rule to remember the symptoms of melanoma:
Asymmetry: One half is different than the other half.
Border irregularity: The edges are notched, uneven, or blurred.
Color: The color is uneven and shades of brown, tan and black are present.
Diameter: Diameter is greater than 6 millimeters.
Evolving: The lesion evolves, or changes, over time.
Upon evaluation, doctors will categorize the nevi into melanotic and non-melanotic lesions.
- Melanotic: Melanotic nevus is a pigmented (colored) lesion derived from melanocytes (the cells that produce melanin)
- Non-melanotic: Non-melanotic nevi are not pigmented.
Diagnosis & Tests
The doctor will perform a thorough skin exam of children with nevus. Depending on the type of nevus, the doctor may need additional tests, which can include a skin biopsy if the diagnosis is in question or if there is a concern for malignancy.
Treatment & Care
The vast majority of nevi do not require treatment. The doctor will recommend surgical removal when there is concern for malignancy. Large nevi may require staged procedures, including serial excisions or the use of tissue expanders. Risks of surgical remove include incomplete removal of lesion, recurrence, and poor scarring.
Doctors recommend proper protection from the sun (like sun block) to prevent skin cancers and to reduce development of acquired nevi.
Living & Managing
Atypical lesions or lesions associated with malignancies require close follow-up from a doctor. Biopsies, where tiny parts of the nevus are removed, may be needed for clinical diagnosis.
With certain nevi, the doctor will examine the child and may recommend treatment of other associated conditions.
Diagnosis and Treatment Available at Texas Children’s:
References & Sources
nevus. 2013. In Merriam-Webster.com. Retrieved April 3, 2013
Corcoran, Julia and Bauer, Bruce S. “Cutaneous Lesions in Children.” Principles & Practices of Pediatric Plastic Surgery, Ed. Michael L. Bentz, Ed. Bruce S. Bauer, Ed. Ronald M. Zuker. St. Louis, MO: Quality Medical Publishing, Inc., 2008. 83-104. Print.
Culliford IV, Alfred and Hazen, Alexes. “Chapter 13. Dermatology for Plastic Surgeons.” Grabb and Smith’s Plastic Surgery, Ed. Charles H. Throne. Philadelphia, PA: Lippincott, 1997. 105-114. Print.