Smaller congenital pigmented or melanocytic nevi are common in children and do not cause problems most of the time. Larger or giant nevi are rare.
A nevus will appear as dark-colored patch with any of the following:
Brown to bluish-black color
Regular or uneven borders
Small satellite areas (maybe)
Smooth, irregular, or wart-like skin surface
Nevi are commonly found on the upper or lower parts of the back or the abdomen. They may also be found on the:
Palms or soles
Signs and tests
You should have all birthmarks looked at by a health care provider. A skin biopsy may needed to check for cancer cells.
An MRI of the brain might be done if the nevus is over the spine. A giant nevus on the spine may be linked to brain problems.
Your doctor will measure the dark skin area every year and take pictures to check if the spot is getting larger.
You will need to have regular exams to check for skin cancers.
Surgery to remove the nevus is be done if possible. Skin grafting is also done when needed. Larger nevi may need to be removed in several stages.
Lasers and dermabrasion can also be used to improve the appearance. These treatments may not remove the whole birthmark, so it may be harder to for the doctors to detect skin cancer (melanoma). Talk to your doctor about the pros and cons of surgery in your case.
Treatment may be helpful if the birthmark causes emotional problems because of how it looks.
Skin cancer may develop in about 1 in 6 people with large or giant nevi. The cancer risk is higher for nevi located on the back or abdomen.
Depression and other emotional problems if the nevi affect appearance
Skin cancer (melanoma)
Calling your health care provider
This condition is usually diagnosed at birth. Talk to your child's doctor if your child has a large pigmented area anywhere on the skin.
Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.