Melanoma is a dangerous and potentially fatal form of skin cancer. It develops when melanocytes—cells responsible for skin pigment—start to grow uncontrollably and form cancerous tumors. The most common sign of melanoma is a mole that changes over time or a new unusual spot on the skin.

Though more frequently found in older adults, melanoma can affect people at any age. When detected early, melanoma is highly treatable. However, once it metastasizes and spreads to other areas, the disease becomes much more difficult to manage. For this reason, recognizing early signs is critical.

Common Symptoms

Melanoma often begins as a mole or skin spot that appears unusual or changes in appearance. These changes may affect an existing mole or show up in a new location on the skin.

how to recognize melanoma using the abcde rule

A helpful tool for identifying potential melanomas is the ABCDE rule:

  • A = asymmetry: One half of the mole does not match the other

  • B = border: Edges are irregular, blurred, or notched

  • C = color: Includes multiple colors like brown, black, red, gray, blue, or white

  • D = diameter: Larger than 6 millimeters (about the size of a pencil eraser)

  • E = evolving: Changing in size, shape, color, or texture; may become itchy, scaly, or bleed

Melanoma can appear anywhere on the body, but it typically develops on areas exposed to the sun. Major risk factors include UV exposure, a family history of melanoma, a weakened immune system, and having many moles.

Superficial Spreading Melanoma Symptoms

Superficial spreading melanoma is the most common type, making up the majority of all melanoma cases. It often presents as a flat or slightly raised area with irregular borders and multiple colors.

features of superficial spreading melanoma

These tumors usually form in the outermost layer of the skin, making them easier to treat in early stages. If not addressed, they can become thicker and begin growing vertically, increasing the risk of spreading.

Nodular Melanoma Symptoms

Nodular melanoma is the second most common type. It appears as a raised growth that protrudes from the skin and often has a dark color.

challenges in identifying nodular melanoma

These melanomas may not follow the ABCDE rule, making them harder to detect. They tend to grow quickly and are often more aggressive than other types.

Lentigo Maligna Melanoma Symptoms

Lentigo maligna melanoma usually appears on areas of skin that receive frequent sun exposure, like the face, particularly in older adults.

progression of lentigo maligna melanoma

It typically starts as a flat, brown or tan spot. Over time, the growth becomes darker, more irregular, and more elevated as the cancer progresses.

Acral Lentiginous Melanoma Symptoms

This type of melanoma typically affects areas less exposed to sunlight, such as the palms, soles of the feet, or under the nails.

common signs of acral lentiginous melanoma

  • Dark brown or black spots that may become raised

  • Sores that don’t heal or bleed

  • Under the nail, a dark line extending from the base to the tip or damage to the nail

Rare Types of Melanoma

Some less common forms of melanoma may appear in different ways and locations:

  • amelanotic melanoma: Lacks pigment; may appear pink or colorless and is often mistaken for benign skin conditions

  • desmoplastic melanoma: Resembles scar tissue; usually slow-growing and lightly colored

  • nevoid melanoma: Mimics the appearance of ordinary, dome-shaped moles; often appears on the upper arms or thighs of younger adults

  • mucosal melanoma: Develops in mucous membranes such as the mouth, nasal passages, vagina, or digestive tract

  • uveal melanoma: Occurs in the eye and is unrelated to skin exposure

Symptoms in Children

Melanoma is rare in people under 20, making up just a small percentage of cases. Because it is so uncommon in this age group, diagnosis may be delayed or missed entirely.

presentation of melanoma in children

Children with many or large moles are at increased risk and may require close monitoring. Melanomas in children may not match the ABCDE criteria used for adults, which can make early detection more difficult.

How Melanoma Affects People Differently

Melanoma rates differ across age, sex, and racial groups.

age and gender differences

In individuals under 50, those assigned female at birth tend to have higher rates. However, after age 50, melanoma becomes more common—and more deadly—in those assigned male at birth. Men more often develop melanoma on the scalp, neck, or back, while women are more likely to have it on the back or legs.

racial disparities

Melanoma occurs more frequently in white individuals than in people of color, likely due to lower melanin levels and increased vulnerability to UV radiation. However, when melanoma does occur in people with darker skin, it is often detected at a later stage—resulting in a worse prognosis.

When to Contact a Healthcare Provider

Monitoring your skin regularly and noting any changes is key to early detection. Even a minor delay in diagnosis can lead to more serious outcomes.

what to look for

  • A new mole or skin lesion

  • Changes in size, color, shape, or texture

  • A spot that bleeds, itches, or doesn’t heal

Using tools like body mole maps or regular photographs can help you track changes over time. If you notice anything suspicious, book an appointment with a healthcare provider or dermatologist without delay.

A Quick Review

Melanoma is a serious skin cancer that can often be treated successfully if caught early. Advances in medical care have greatly improved outcomes, especially in early-stage cases.

However, once melanoma spreads beyond the skin, survival rates decrease significantly. That’s why it’s essential to watch your skin closely for new or changing spots and seek medical attention when in doubt.