There are many different kinds of birthmarks and the answer to your question depends on the type of birthmark.
Some birthmarks are vascular, that is made up primarily of blood vessels. These are called hemangiomas and generally do not increase the risk of skin cancer. Very often this type of birthmark will fade and disappear with time.
Pigmented nevi (moles) are a different story. They have an increased risk of developing into skin cancer, particularly into melanoma. This is especially true if they are congenital (present at birth) or if they are very large (giant nevi). Any pigmented nevus should be watched closely and if there is a significant change in size, color or shape, it should be evaluated and possibly removed.
There is one type of birthmark that bears special mention. It is present at birth and occurs in the scalp. It is called “Nevus Sebaceous of Jadassohn.” It appears as an area without hair and generally looks gray or yellowish and may be cobble stoned (rough). This particular nevus has a 10 to 15 percent chance of becoming malignant as one gets older. It should be removed as early as feasible and certainly by the end of the first decade.
Again, remember if a birthmark changes in size, color, shape or becomes friable (bleeds easily) it should be promptly evaluated.
For more information, check out this article:
Common Skin Problems: Hives, Impetigo, Moles, White Spots
Posted 12-22-04
