- Melanoma is considered the deadliest form of skin cancer, and it is important to catch it early.
- While it often appears as an asymmetrical mole, there are some rarer signs as well.
Skin cancer is the most common form of cancer in the US, and the American Cancer Society estimates that over 97,000 new cases of melanoma, the most aggressive and deadly type of skin cancer, are expected to be diagnosed in 2023.
While wearing sunscreen and getting annual skin checkups are all important, self-monitoring skin changes is one of the most significant things you can do to quickly catch melanoma, which accounts for about 1% of all skin cancers, but the majority of skin cancer deaths.
In the majority of cases, diagnoses are usually patient-driven, said Dr. Alexander Witkowski, an assistant professor of dermatology at the OHSU School of Medicine, who recently diagnosed the world's smallest skin cancer. He said more than half of melanoma cases are spotted by the patient (or someone the patient knows) who may notice changes to a mole.
His wife, Dr. Joanna Ludzik, who collaborated with him on the record-breaking discovery and is also an assistant professor of dermatology at OHSU, recommended doing self-checkups every 3-4 months and following the ABCDE method by looking for a mole's asymmetry, border, color, diameter and evolution.
But melanoma doesn't always occur on moles — in fact, 70-80% of melanoma cases form on "normal-looking" skin. Sometimes it occurs in subtle areas that can be more unexpected, but just as dangerous, the doctors said. Insider spoke to them about the less-obvious signs of melanoma, and when you should see a doctor.
New spots on the soles of your feet or inner hands should be checked out
While melanated skin tones can filter out UV rays more effectively, resulting in lower rates of skin cancer, there are a few areas of the body that are at higher risk of developing melanoma, especially for people with darker skin: The soles of your feet and the insides of your hands.
Regardless of your race or skin tone, Witkowski said everyone "has the same amount of pigment in these limited areas, so the risk level is pretty much the same" if, for example, the bottoms of your feet get sunburned.
Because this isn't always common knowledge, Black Americans may be disproportionately affected by melanoma in these areas, according to Witkowski. One famous case was Bob Marley, whose fatal melanoma began as a lesion on his toe.
Streaks on fingernails and toenails could also be a sign
Melanoma is usually associated with asymmetrical moles, but it can also present as a long, dark streak underneath fingernails and toenails, according to Witkowski and Ludzik. For that reason, they said it's important to always remove any nail polish prior to skin exams.
Lesions on your eyelids, lips, or genitals
Known as mucosal melanoma, new skin lesions on your eyelids, lips, and genitals could also be signs of melanoma, according to Witkowski and Ludzik. Luckily, they said, this form of melanoma can be easier to spot as it usually appears as darker, more eye-catching lesions.
A colorless mole
A rare form of melanoma is nicknamed "pink melanoma" because it presents as a mole without visible pigment.
According to Ludzik, it usually looks like a small pink or white spot — and one that can grow rapidly, so noticing it early and getting it checked out is crucial. One telltale sign is it might shine under a light or mirror.
On your eyeball
Witkowski said this type of melanoma is very rare, and represents less than 1% of all melanoma cases. But at skin checkups, dermatologists should still take a look at your eyes just in case, because sometimes melanoma can form on the backside of the eyeball.
He said that in the majority of these cases, the patient will first notice a change in vision, eye pressure, or new headaches that lead to a melanoma diagnosis.