expert advice MORE
Q: My six-year-old daughter has a large birthmark about the size of a quarter on her thigh. It's a dark brown color, not black, and it does have hair growing out of it. She's had this since birth, and I do wonder if this may need to be removed or if I should worry about it at all.
A: What you are describing sounds like a collection of pigmented cells in your daughter's skin, often referred to as a "nevus." These areas can be flat or raised and can be various shades of brown, blue, or black. They can have coarse hairs coming out of it and some of them can be fairly large. They can also have small, satellite lesions about the outside rim.
The size of your daughter's lesion doesn't have special significance to me. It sounds like this area hasn't necessarily gotten bigger, hasn't changed in color, doesn't have irregular borders, nor has it bled on its own. I am assuming it's just growing with your daughter as she does and that she is developmentally normal.
When there are giant congenital nevi larger than 20com, patients should be seen by a pediatric dermatologist for exact management. These are ones where the incidence of malignant melanoma is higher and an association with neurologic problems has been documented.
Controversy does exist concerning the appropriate approach for medium-sized or smaller congenital nevi, such as you're describing. Whether there is a definitive increased incidence of melanoma arising from these smaller lesions is not clear. In general, these are usually not a problem. However, there is some thinking that they may pose an increased risk over a lifetime for development of malignant melanoma, so the prevailing, but not universal, opinion is that consideration be given to removing these nevi prior to adolescence. Benign appearing flat lesions of uniform color may be observed regularly by your physician until later childhood, when they can be removed under local anesthesia. If there is any question, a dermatologist (skin specialist) can examine your daughter's nevus and give you the most current wisdom.
More on: Expert Advice
Henry Bernstein, M.D., is currently the associate chief of the Division of General Pediatrics and director of Primary Care at Children's Hospital, Boston. He also has an academic appointment at Harvard Medical School.