Skin Problems & Treatments Health Center

Congenital nevi are moles that are present at birth. These birthmarks have a slightly increased risk of becoming skin cancer depending on their size. Larger congenital nevi have a greater risk of developing skin cancer than do smaller congenital nevi. All congenital nevi should be examined by a health care provider and any change in the birthmark should be reported.

If a dermatologist believes a mole needs to be evaluated further or removed entirely, he or she will either remove the entire mole, or first take just a small tissue sample of the mole to examine thin sections of the tissue under a microscope (a biopsy). This is a simple procedure. (If the dermatologist thinks the mole might be cancerous, cutting through the mole will not cause the cancer to spread.) Read more about moles, freckles, and skin tags.