What is Melanoma? Identifying Skin Cancer & Cancerous Moles

Melanoma skin cancer is the most serious form of skin cancer that occurs when pigment-producing cells (melanocytes) grow out of control. This aggressive form of skin cancer can develop anywhere on the body, but most commonly appears in areas exposed to the sun, such as the face, neck, chest, back, shoulders, and legs. While asking “what is melanoma?” is common, understanding its characteristics is crucial for early detection. For comprehensive information, download our free Skin Cancer eBook.

While melanoma is the least common type of skin cancer, accounting for only 2% of all skin cancer cases, it is also the most serious and dangerous.

In this article, we’ll discuss what melanoma is, how to recognize it, and steps you should take if you think you might have this type of skin cancer.

Human skin is made up of a handful of different types of cells. Each type serves a different role in the normal functioning of the skin.

Melanocytes are found in the deepest part of the top layer of skin, called the basal layer. They account for 5 to 10% of the cells in the basal layer.

Melanoma is a type of skin cancer caused by damage to the DNA of melanocyte cells in the skin.

Melanoma lesions may form suddenly or may evolve from existing moles. While melanoma can take on many different forms, the general warning sign is a changing or atypical mole.

Cancerous moles, or melanomas that develop from existing moles, typically exhibit changes that can be monitored using the ABCDE method. Not all changing moles become cancerous, but any change in size, shape, color, or sensation warrants medical attention. Approximately 20-30% of melanomas develop from existing moles, while the majority appear as new lesions.

Melanoma frequently forms on areas of the skin that receive frequent exposure to UV light from the sun, including:

• Back
• Legs
• Arms
• Face

But melanoma may occur anywhere on the body, including palms, soles of the feet, and underneath fingernails. Rarely, melanoma can form in parts of the body other than the skin, such as the mouth, eyes, or intestines.

What does melanoma look like in its early stages? Melanoma lesions often appear as unusual moles with irregular borders, uneven coloration, and asymmetrical shapes. Early melanomas may be flat or slightly raised and can range in color from black or brown to red, blue, white, or even skin-colored. As melanoma progresses, the lesion typically grows in size, changes in appearance, and may become painful, itchy, or bleed easily when irritated.

Consult a doctor if you notice changes in your skin. These may include red flags such as:

•  The sudden appearance of new moles or growths
• Moles that change in size over time (exceeding 1/4 inch)
• Asymmetrical moles
• Moles with uneven borders
• Moles that change in color
• Moles that begin to itch, bleed, or become sore

Moles are a normal part of skin for many people. Most people have between 10 and 50 on their body. Since many melanomas form from existing moles, it’s important to check your skin every few months and to know the signs of melanoma should they appear. To distinguish between them, here are some common characteristics of normal moles :

•  Uniform color (often black, brown, or skin-colored)
• Clearly defined edges with a distinct border between the surrounding skin
• A round or oval shape
• A diameter no larger than 1/4 inch, or roughly the size of a pencil eraser

Understanding the difference between a normal mole and a melanoma mole is critical for early detection. When a regular mole transforms into melanoma, it typically shows one or more of the ABCDE warning signs. A melanoma mole may evolve from an existing mole or appear as a new growth, often with irregular borders, varied colors, or unusual shape. Regular self-examination to identify potentially cancerous moles can literally save lives.

Click here to view a printable version of the ABCDE chart.

Melanoma is the most dangerous skin cancer, but it’s certainly not the only one. The two most common skin cancers include basal cell carcinoma and squamous cell carcinoma. Fortunately, these skin cancers aren’t life-threatening and are nearly always curable.

However, if left untreated, they can cause disfiguration and long-term nerve damage. For this reason, it’s important to take skin cancer – whether melanoma or another type – very seriously and consult your doctor if you suspect skin cancer.

To help you identify these skin cancers, basal and squamous cell carcinoma differ in appearance from melanoma. They also range in severity, depending on the skin tissue and the individual’s risk factors.

Basal cell carcinoma often looks like a flesh-colored bump or pink patch, and is commonly found on the head, neck and arms. Frequent sun exposure and indoor tanning are the strongest risk factors for getting this skin cancer. Those with fair skin may also be more prone to getting basal cell carcinoma.

Squamous cell carcinoma is another common skin cancer that often looks like a red bump or scaly patch. It’s frequently found on the face, neck, arms, chest and back. Once again, frequent sun exposure is the most significant risk factor.

Though these skin cancers aren’t as life-threatening as melanoma, it’s still essential to get early diagnosis to avoid their more serious consequences.

Long-term exposure to UV rays, or specific incidences of brief, intense exposure resulting in severe, blistering sunburns, are believed to be the most common cause of melanoma. Both sunlight and UV rays from tanning beds may cause damage. However, as with all cancers, melanoma is likely the result of both environmental and genetic factors.

The following characteristics may put you at greater risk of developing melanoma:

• History of severe, blistering sunburn.
• Fair skin. People with less melanin in their skin, those with light-colored eyes and blonde or red hair, and those with freckles, have less built-in protection from UV radiation and are at greater risk of developing melanoma.
• Frequent sunburns in early childhood.
• Family history of skin cancer, especially melanoma.
• Having a large number of moles (more than 50) or atypical moles.
• Weakened immune system, caused by medical conditions such as HIV/AIDS, or medical treatments such as chemotherapy.

Your doctor or dermatologist will first diagnose melanoma through a physical exam. He/she will check your skin from head to toe for typical signs of melanoma. This exam will take a thorough look at moles and skin tissues all over your body.

If any skin tissue seems suspicious, your doctor will perform a biopsy on it. The lab will then process it to find out if the tissue contains cancer cells.

If the results come by positive, your doctor will also analyze the melanoma to understand how far along the cancer is. By looking at the characteristics of the tissue (thickness, deepness, etc.) and whether it’s spread to other areas, he/she will identify the current stage of skin cancer.

Sometimes you may need to take additional exams, such as PET scans, CT scans, MRIs and blood tests so your doctor can fully understand the extent of melanoma. Generally speaking, melanoma is considered a lower risk if it’s localized, i.e. hasn’t spread to other areas of the body.

Melanoma can be organized into several different stages, ranging from lowest to highest risk. In early stages (stages 0-2), the skin cancer hasn’t yet spread to other areas of the body, while in advanced stages (3-4), cancer cells may have reached lymph nodes or even organs.

In all stages of melanoma, you will require treatment to remove the affected skin tissue or undergo other appropriate therapies.

Overall, melanoma can be understood through these standardized stages of skin cancer:

•  Stage 0: Melanoma is contained to the outermost layer of skin.
• Stage I: Melanoma has penetrated the top layer of the skin and is smaller than 1 mm in depth.
• Stage II: Melanoma is deeper than 1 mm, but still hasn’t spread to other areas. The risk for spreading may be high, especially if thicker than 4 mm or ulcerated.
• Stage III: Melanoma has spread to the lymph nodes or a lymph vessel. The level of risk depends on how much it has progressed (i.e. how many nodes, how many cancer cells found in them, etc.).
• Stage IV: Melanoma has spread to other lymph nodes or even organs, putting the patient at very high risk.

Your doctor will identify the stage of melanoma and create a plan to treat the cancer accordingly. Remember that melanoma detected in early stages is highly curable, with a 99% five-year survival rate.