Last week, we discussed the importance of annual skin exams to help increase your chances of catching melanoma early. 

Another key to early detection is understanding what skin cancer looks like, as it can easily be mistaken for a freckle or mole. 

Understanding the four main types of melanoma and how they change over time can help you work with your dermatologist to find and diagnose suspicious spots. 

The 4 Main Types of Melanoma

70% of cases are superficial spreading melanoma. It tends to grow outwards across the surface of the skin. It is often flat and less than 1 mm thick with an uneven border. It can sometimes start from a preexisting mole. It most commonly appears on the trunk, arms, and legs.  

15-20% of cases are nodular melanoma. Instead of spreading across the skin, this form grows down into the skin. Nodular melanoma spreads more quickly than other types, manifesting as a raised growth called a polypoid that resembles a mushroom and stem or a stalk. Typically, it starts on the face, chest, or back. 

10-15% of cases are lentigo maligna melanoma. Older people are more prone to this type of melanoma. It appears as a flat brown patch with an uneven border and gets darker as it grows. Lentigo maligna melanoma is known to grow out across the skin for many years before it begins to grow down. Areas exposed to the sun unprotected, like the ears, face, and arms, are prone to this form. 

5% of cases are acral lentiginous melanoma, which is most often seen in darker skin tones. Unlike the other three forms, it is not caused by exposure to UVA or UVB rays. Like lentigo maligna melanoma, it will grow outwards across the surface of the skin for years before growing down, appearing as a small, flat spot of discolored skin. Dermatologists often find it on the soles of the feet, palms of the hands, and under the nails. 

The ABCDEs of Melanoma

When performing self-checks, a handy acronym can be your guide for recognizing the signs of melanoma:

A is for Asymmetry. Unlike benign moles, which are round or oval-shaped, melanomas are asymmetrical, meaning that if you were to draw a line down the middle of the spot, the two halves would be different.

B is for Border. If the outer edge of the spot is wavy, notched, or splotchy, it may be a sign of melanoma. 

C is for Color. Common moles are uniformly brown, whereas a melanoma lesion may have many different shades of tan, brown, and black.

D is for Diameter. Spots larger than a pencil eraser in diameter, around 1/4 inch, is a warning sign of melanoma. 

E is for Evolving. Unlike moles or freckles, cancerous lesions change over time. Check for changes in size, shape, color, or thickness of the spot. Also, be aware of any itching, bleeding, or tenderness at the location. 

Melanoma has a 99% 5-year survival rate when detected early. Checking in often with your dermatologist, especially as you age, is critical to your long-term skin health. Schedule a skin exam with one of the providers at Advanced Dermatology & Cosmetic Institute, especially if you have concerns about a spot that meets any of the criteria for melanoma. Please be sure to provide information regarding your family history of skin cancer at your appointment.