Melanoma – Symptoms and Causes

Overview

Melanoma is a type of skin cancer that starts in melanocytes, the cells that produce skin color. This cancer typically develops in sun-exposed areas such as the arms, back, face, and legs.

Melanoma mainly affects the skin, but it can also occur in the eyes and, rarely, in areas like the nose or throat.

UV radiation exposure is the primary known cause of melanoma. This exposure comes from sunlight or artificial sources like tanning beds. By reducing UV exposure, you can lower your melanoma risk.

There’s a concerning trend of increasing melanoma cases in people under 40, particularly women. Early detection is crucial for successful treatment, making it important to recognize skin cancer symptoms promptly.

Melanoma caught in its early stages has excellent treatment outcomes. Regular skin checks and protection from UV radiation are key prevention strategies.

Warning Signs

Normal Spots

Normal skin spots usually have one color, like pink, tan, brown or black. People with darker skin tend to have darker spots. These spots have clear borders that separate them from the surrounding skin.

They are round or oval and typically smaller than 1/4 inch (about 6 millimeters) across.

Most spots start appearing during childhood. New discolorations can develop until approximately the age of 40. Adults usually have between 10 and 40 spots. These spots can change over time, and some might fade as you get older.

Red Flags for Skin Cancer

Some spots look unusual and might be skin cancer. Watch for these warning signs:

• Uneven shape – Spots with odd shapes or two different-looking halves.
• Color changes – Spots with multiple colors or unusual color patterns.
• Size changes – New growth larger than 1/4 inch (about 6 millimeters).
• New symptoms – Itching or bleeding that wasn’t there before.
• Irregular edges – Spots with jagged, notched, or scalloped borders.

Cancerous spots can look very different from each other. Some might show all these changes, while others might show only one or two unusual features.

Spots in Hidden Areas

Skin cancer can also develop in places that get little or no sun exposure. These “hidden” spots can appear between toes, on palms, soles, scalp or genitals. People with darker skin are more likely to develop skin cancer in these hidden areas.

Hidden skin cancers include:

• Internal Cancers – These develop in the mucous membranes that line areas like the nose, mouth, esophagus, anus, urinary tract, and vagina. These are hard to detect because they can look like other common conditions.
• Eye Cancers – These most often occur in the tissue layer beneath the white of the eye (uvea). They may cause vision changes and are usually found during eye exams.
• Nail Bed Cancers – This rare form can appear under fingernails or toenails, or on palms or soles. These spots tend to be very dark and flat with unusual borders. They’re more common in people of Asian descent and those with darker skin.

When to Call a Doctor

Contact your healthcare provider if you notice any skin changes that concern you. This is especially important if you notice a new spot or changes in an existing spot.

Warning Signs to Watch For	What to Look For
Shape	Asymmetrical or irregular shape
Border	Jagged, blurry, or poorly defined edges
Color	Multiple colors or unusual patterns
Size	Larger than 1/4 inch or growing
Changes	New symptoms like itching or bleeding

Causes

Melanoma begins when healthy melanocytes—the skin cells responsible for producing melanin, which gives skin its color—undergo changes and become cancerous.

The root of these changes lies in alterations to the melanocytes’ DNA. DNA contains instructions that control cell behavior, including growth and death cycles. When DNA changes occur, these instructions become corrupted.

The altered cells begin to multiply rapidly and avoid the normal cell death process. This leads to an accumulation of cells that shouldn’t exist.

These excess cells may form tumors that can invade surrounding healthy tissue. Over time, cancer cells may break away from the original tumor and spread to other body parts, a process called metastasis.

Scientists haven’t determined exactly what causes the DNA changes that lead to melanoma. The condition likely results from a combination of environmental and genetic factors working together.

Exposure to ultraviolet (UV) light stands as the primary known cause of melanoma. UV light comes from:

• Sunlight
• Tanning beds
• Tanning lamps

However, not all melanomas result from UV exposure. Melanomas sometimes develop in areas that rarely or never see sunlight, suggesting other factors play important roles in some cases.

Risk factors that may contribute to melanoma development include:

Factor	Description
Fair skin	Less melanin means less protection from UV radiation
Family history	Genetic factors increase risk
Weakened immune system	Reduced ability to fight abnormal cells
Previous melanoma	Higher risk of developing additional melanomas

Risk Factors

Several factors can increase your chance of developing melanoma:

• Family History: Having a close family member, such as a parent, sibling, or child with melanoma raises your risk significantly.
• Sunburn History: Experiencing one or more severe sunburns, especially those that blister, puts you at higher risk for developing melanoma later in life.
• UV Light Exposure: Exposure to ultraviolet light from the sun or tanning beds damages skin cells and increases melanoma risk over time.
• Mole Characteristics: Two mole-related factors increase risk:
  • Having more than 50 regular moles on your body
  • Having dysplastic nevi (unusual moles that are larger, with irregular borders and varied colors)
• Geographic Location: People face higher melanoma risk if they:
  • Live closer to the equator, where sun rays are more direct
  • Live at higher elevations, where UV exposure is greater
• Skin Type: While melanoma can affect anyone, people with certain physical traits face higher risk:
  • Fair skin that burns easily
  • Blond or red hair
  • Light-colored eyes
  • Tendency to freckle
• Immune System Function: A weakened immune system increases melanoma risk. This includes people:
  • Taking immunosuppressive medications after organ transplants
  • With certain medical conditions that compromise immunity

Ways to Protect Your Skin

You can take steps to lower your risk of melanoma and other skin cancers by making simple changes to your daily habits.

• Stay away from tanning equipment. Tanning beds and lamps emit UV light that can harm your skin and increase cancer risk.
• Limit sun exposure during peak hours. In North America, the sun is strongest between 10 a.m. and 4 p.m. Plan outdoor activities outside these hours, even on cloudy or winter days.
• Know your skin. Check yourself regularly for new growths, changes in existing moles, and differences in freckles or birthmarks. Use mirrors to examine hard-to-see areas like your back, scalp, and between toes.
  • Don’t forget to check your genital area and between buttocks.
• Dress for protection. When outdoors during daylight, wear dark, tightly woven clothes covering your arms and legs. Choose a broad-brimmed hat rather than a baseball cap, and select sunglasses that block both UVA and UVB rays.
• Apply sunscreen consistently. Use these guidelines:

1. Choose broad-spectrum protection with SPF 30 or higher.
2. Apply generously to all exposed skin.
3. Reapply every two hours.
4. Use more frequently when swimming or sweating.
5. Wear sunscreen year-round, even on cloudy days.