Benign Skin Growths and Spots
During my dermatology elective, I encountered countless patients who were concerned about growths on their skin that were, in fact, harmless and very common. There are thousands of lesions that can appear on the skin, but here I will discuss a few of of the most commonly seen benign skin spots and growths. I will also discuss what kind of changes to be cautious of when examining growths and moles. When in doubt, consult with your dermatologist.
1. Freckles (“Ephelides”): these small, flat light-brown spots are small, multiple, and irregularly shaped. They appear in childhood, darken during the summer months, and lighten during the winter months (waxing and waning in response to sun exposure). They are due to a local, superficial accumulation of melanin, the protein the gives pigment to our skin and protects us from the sun. They are more common in lighter-skinned individuals who sunburn more easily. Sometimes these fade with age. The best way to avoid new freckles is by good sunprotection.
2. “Solar lentigos” (aka liver spots, age spots, or sun spots): these brown spots appear similar to freckles, but have sharper margins and sometimes stand alone. They can be found on the backs of hands, the shoulders, and the head and neck of adults. They are caused by sun damage acquired over time, but their appearance is persistent (they do not darken or lighten with the sun, or with time). They are due not only to a local accumulation of melanin, but also to a local increase in the cells that produce melanin (“melanocytes”). Some consider them to be flat versions of seborrheic keratoses (see below). Though not harmful, they can be treated for cosmetic reasons with freezing (“cryosurgery”), chemical peels, or certain lasers.
3. Café-au-lait spots: these light-brown “macules” (flat, smaller than 0.5cm) and “patches” (flat, greater than 0.5cm) appear within the first year of life. They are due to a local increase in melanin. If a child has greater than 5 café-au-lait spots >1.5cm, they should be tested for syndromes such as neurofibromatosis.
3. Junctional nevi: these darker brown, sharply bordered, flat lesions are a type of mole (“nevi” = mole). Moles have specific features under the microscope. They do not need to be removed unless there are features concerning for melanoma (see the ABCDE rules below). Removal is by cutting them out (“excision”); be mindful that excisions leave scars.
*There are many types of flat and elevated moles. Some have more pigment, and some are skin-colored. We will discuss at the end how to monitor moles.
Signs of Wisdom – seen more commonly in people age 30+
1. Seborrheic Keratoses (SKs): sometimes referred to as barnacles, these light tan to dark brown waxy growths appear to be “stuck on” to the skin, as if they could be peeled off with your fingernail. They have a rough, warty surface, and they can grow up to 1” (2.5cm) in width. SKs are caused by skin cells from the top layer of the epidermis (“keratinocytes” in the “stratum corneum”) sticking together. Some think they may be related to sun exposure. There is no need to remove these growths, as they are completely harmless, but if they become irritated or cosmetically undesirable, they can be removed by freezing (“cryotherapy”), burning with an electric current (“electrocautery”), or scraping.
2. Skin Tags: these smooth, fleshy growths hang on to the skin by a little stalk. These are commonly acquired in areas of friction. Though they are harmless, if irritated or undesired they can be removed by snipping with scissors or freezing.
3. Cherry angiomas: the cherry-red raised round bumps (“papules”). They often start out flat and become dome-shaped. They are caused by an abnormal growth within capillaries, the smallest blood vessels. In the rare case that the patient desires removal, they can be burned off with electrocautery or zapped with a laser.
Monitoring moles and other growths and spots:
One of the most important rules of thumb in screening for melanoma is the ugly duckling sign: spotting the mole or growth that does not look like the others. A lesion is often not concerning if you have others that look like it on your body.
Monitor your moles by following the ABCDEs. The most important of these is E – EVOLVING—if you notice any change in your moles, or any appearance of new moles, mention this to your dermatologist during your check-up. [*Make note that even benign moles can grow. Not all change is melanoma.]
A – ASYMMETRY: if your mole has become uneven or asymmetric, have it looked it.
B – BORDER: benign moles have nice, regular borders. Dangerous moles have irregular borders.
C – COLOR: benign moles usually have only one color. Dangerous moles can have two or more.
D – DIAMETER: benign moles are usually smaller than a pencil eraser (<6mm).
E – EVOLVING: changes in your moles or the appearance of new moles should prompt examination.