Ask Doctor K: Checklist to detect melanoma

DEAR DOCTOR K: My aunt developed the skin cancer called melanoma, and I hear that this cancer can run in families. What should I look for?

DEAR READER: Skin cancers are the most common cancers in the United States, and skin checks are an important way to identify them. You asked about the deadliest type of skin cancer, melanoma.

My Harvard Medical School colleague, dermatologist Dr. Kenneth Arndt, said more than half of melanomas are identified by patients. That’s important because more than 90 percent of cases can be cured with early detection and treatment.

Skin cancers form in the epidermis, the outermost layer of the skin. Cells called melanocytes, located in the epidermis, produce a dark pigment called melanin. This pigment colors skin and helps protect against the sun’s ultraviolet rays. Melanoma begins in the melanocytes.

Often, these melanocytes are part of a pigmented spot on the skin called a mole (the medical term is “nevus”) that is not cancerous. However, the melanocytes in the nevus can start to turn cancerous. That changes the appearance of the pigmented spot on the skin. Without early detection and treatment, melanoma can spread, and sometimes is fatal.

You can help to detect early skin changes by taking a few minutes each month to inspect your skin. Melanoma has several distinguishing features.

If you have a pigmented area with any of these characteristics, see a dermatologist.

Asymmetry: Each half of the mole looks different than the other.

Border irregularity: The borders are irregular, ragged or blurry.

Color: The color is unusual – a mole that contains various shades of tan, brown, blue or black.

Diameter: The width of the mole is the size of a pencil eraser or larger.

Evolving: The mole has evolved, enlarged or changed in some way. Sores that crust, bleed and itch are also suspect.