Melanoma

Melanoma is a type of skin cancer that develops when melanocytes (the cells that give the skin its tan or brown color) start to grow out of control. Most melanomas start in the skin. Another name for these cancers is cutaneous melanoma. Melanoma is much less common than some other types of skin cancers, accounting for only about one percent of cases. But it’s more dangerous because it’s much more likely to spread to other parts of the body if not found and treated early. 

Types & Stages

There are several different types of skin melanoma. The most common types are:

• Superficial spreading melanoma. These tumors tend to grow outward on the surface of the skin (at least at first), so they might be noticed as a dark spot on the skin that is changing shape and/or getting bigger. Some of these melanomas start in existing moles. They make up about 7 in 10 melanomas of the skin.
   
• Nodular melanoma. These tumors often appear as a distinct, raised bump (nodule) on the skin that is often dark brown or black, but it can also be pink or red. This can make it hard to find early. Nodular melanomas tend to grow down into deeper layers of the skin fairly early, so they’re often at a more advanced stage than superficial spreading melanomas by the time they’re found. They account for about 2 in 10 skin melanomas. 
   
• Lentigo maligna melanoma. It often first appears as an abnormally shaped tan or brown spot in an area that gets a lot of sun (such as the face, ears or arms), and it tends to grow slowly (or change in other ways) over time. It’s more likely to occur in older people. 
   
• Acral lentiginous melanoma (acral melanoma). This type of melanoma starts in areas that don’t get a lot of sun exposure, such as the palms, soles or under the nails. Acral melanomas make up a large portion of melanomas in people with darker skin tones.

Melanomas can also form in other parts of the body, such as:

• Inside the eye (known as ocular melanomas). Most of these start in the uvea (the middle layer of the eyeball) and are known as uveal melanomas.
   
• Inside the nose, mouth, throat, genital or anal area (known as mucosal melanomas).

These are much less common than melanoma of the skin.

Signs & Symptoms

If you have one of the warning signs of melanoma, have your skin checked by a doctor. These include:

• They can start anywhere on the skin, but in people with lighter skin color they’re more likely to start on the trunk (chest and back) in men and on the legs in women. The neck and face are other common sites. People with darkly pigmented skin have a lower risk of melanoma at these more common sites.
   
• The most important warning sign of melanoma is a new spot on the skin or a spot that is changing in size, shape or color.
   
• Another important sign is a spot that looks different from all of the other spots on your skin. (This is sometimes known as “the ugly duckling sign.”)

The ABCDE rule is another guide to the usual signs of melanoma. Be on the lookout and tell your doctor about spots that have any of the following features:

• A is for Asymmetry: One half of a mole or birthmark doesn’t match the other.
• B is for Border: The edges are irregular, ragged, notched or blurred.
• C is for Color: The color is not the same all over and may include different shades of brown or black, or sometimes with patches of pink, red, white or blue.
• D is for Diameter: The spot is larger than 6 millimeters across (about ¼ inch – the size of a pencil eraser), although melanomas can sometimes be smaller than this.
• E is for Evolving: The mole is changing in size, shape, or color.

Some melanomas don’t fit these rules. It’s important to tell your doctor about any changes or new spots on your skin, or growths that look different from the rest of your moles.

Diagnosis

Melanoma can often be found early when it’s most likely to be cured. Knowing your own skin is important to finding skin cancer early. You should know the pattern of moles, blemishes, freckles and other marks so that you’ll notice any new growths or changes in existing moles or other spots. Many doctors recommend checking your own skin, preferably once a month. 

Some doctors do skin exams as part of routine health checkups. If your primary doctor finds any unusual moles or other suspicious areas, they may refer you to a dermatologist, a doctor who specializes in skin problems. Dermatologists can also do regular skin exams. Many dermatologists use a technique called dermoscopy (also known as dermatoscopy, epiluminescence microscopy [ELM] or surface microscopy) to look at spots on the skin more clearly. 

If you have signs or symptoms of melanoma, your doctor will examine you and ask you questions about your health, your lifestyle and your family history. If your doctor suspects a spot may be melanoma, a biopsy will be done because melanoma skin cancer cannot be diagnosed just by looking at it. Your doctor may use one of these methods:

• Local excision/excisional biopsy. The entire suspicious area is removed with a scalpel under local anesthetic. Depending on the size and location of the suspicious area, this type of biopsy may be done in a doctor's office or as an outpatient procedure at a hospital. Your doctor will put in stitches to close the excision and cover the area with a bandage.
   
• Punch biopsy. For this, a tool that looks like a tiny round cookie cutter is used to remove a deeper sample of skin. Your doctor rotates the punch biopsy tool on the skin until it cuts through all the layers. The sample is then removed, and the edges of the biopsy site are stitched together.
   
• Shave biopsy. This biopsy procedure, also known as saucerization, shaves off the top layers of the skin with a small surgical blade. Any bleeding is then stopped by putting either an ointment or a chemical that stops bleeding on it, or by using a small electrical current to seal (cauterize) the wound.

The sample of skin is sent to a pathologist, who looks at it under a microscope to check for cancer cells. Your tissue may be judged normal or abnormal. Abnormal results may include:

• benign (non-cancerous) growths such as moles, warts and benign skin tumors
• squamous cell carcinoma (cancer)
• basal cell carcinoma
• melanoma

After melanoma has been diagnosed, tests may be recommended to find out if cancer cells have spread within the skin or to other parts of the body. These may include imaging tests, such as:

• chest X-ray
• lymphoscintigraphy
• ultrasound
• CT or CAT (computed axial tomography) scans
• MRI (magnetic resonance imaging) scans
• PET (positron emission tomography) scans

Treatment    

Surgery is the main treatment option for most melanomas and it usually cures it at the early stage. These include: 

• Wide excision is used when melanoma is diagnosed by a skin biopsy and more surgery will probably be needed to help make sure the cancer has been removed (excised) completely. This fairly minor operation will cure most thin melanomas. Local anesthesia is injected into the area to numb it before the excision. The site of the tumor is then cut out, along with a small amount of normal skin around the edges (called the margins). The wound is usually stitched back together afterward. The removed sample is then viewed with a microscope to make sure that no cancer cells were left behind.
   
• Mohs surgery. Also known as Mohs micrographic surgery or MMS, this might be an option for some very early-stage melanomas that are in areas where a wide excision would be hard to do (such as the face or ears). This type of surgery is done by a specially trained dermatologist or surgeon. In this procedure, the skin (including the melanoma) is removed in very thin layers. Each layer is quickly frozen and looked at with a microscope. If cancer cells are seen, the doctor removes another layer of skin. This is repeated until a layer shows no signs of cancer. This is a slow process, often taking several hours, but it means that more normal skin near the tumor can be saved, which can help the area look better after surgery.
   
• Amputation. In uncommon situations where the melanoma is on a finger or toe and has grown deeply, part or all of that digit might need to be amputated.
   
• Lymph node dissection. In this operation, the surgeon removes all of the lymph nodes — small structures that work as filters for foreign substances, such as cancer cells and infections, in the lymphatic system — in the region near the primary melanoma tumor. 
   
• Surgery for metastatic melanoma. If melanoma has spread (metastasized) from the skin to other organs such as the lungs or brain, the cancer is very unlikely to be curable by surgery. Even when only one or two areas of spread are found by imaging tests such as CT, MRI or PET scans, there are likely to be others that are too small to be found by these scans. Surgery is sometimes done in these circumstances, but the goal is usually to try to control the cancer rather than to cure it. If one or even a few metastases are present and can be removed completely, this surgery may help some people live longer. Removing metastases in some places, such as the brain, might also help prevent or relieve symptoms and improve a person’s quality of life.

There are other non-surgical treatments for melanoma, including:

• Targeted cancer therapy. Drugs are used to attack specific cancer cells. This “targeted” approach goes after cancer cells, leaving healthy cells untouched.
   
• Radiation Therapy. Includes treatments with high-energy rays to attack cancer cells and shrink tumors.
   
• Immunotherapy. This stimulates your own immune system to help fight the cancer.

Causes & Risk Factors

There are several risk factors can make a person more likely to develop melanoma: 

• Age. The risk of melanoma increases as people age, but melanoma can also develop in younger people. In fact, melanoma is one of the most common cancers in people younger than 30 (especially younger women). Melanoma that runs in families may occur at a younger age.
   
• Gender. In the United States, men are more are more likely than women to get melanoma, although this varies by age. Before age 50, the risk is higher for women; after age 50, the risk is higher in men.
   
• Exposure to ultraviolet (UV) light. This includes sunlight, tanning beds and sun lamps.
   
• Having many moles. Most moles will never cause any problems, but someone who has many moles is more likely to develop melanoma.
   
• Lighter skin, hair and eye color. The risk of melanoma is much higher for people with lighter skin color than for people with darker skin. Among people with lighter skin, those with red or blond hair, blue or green eyes, or skin that freckles or burns easily are at increased risk.
   
• Family history of melanoma. Your risk of melanoma is higher if one or more of your first-degree relatives (parents, brothers, sisters or children) has had melanoma. Around 1 in 10 people with melanoma have a family history of the disease. If at least one close relative has had melanoma, this condition is referred to as familial atypical multiple mole and melanoma (FAMMM) syndrome. People with this condition have a very high lifetime risk of melanoma, so they need to have very thorough, regular skin exams by a dermatologist.
   
• Personal history of melanoma or other skin cancers. A person who has already had melanoma has a higher risk of getting melanoma again. In people who’ve had several melanomas or who’ve had melanoma at an early age, doctors might advise genetic counseling and testing to see if they have gene mutations that increase their risk. People who have had basal or squamous cell skin cancers are also at increased risk of getting melanoma.
   
• Having a weakened immune system. A person’s immune system helps the body fight off skin cancers. People with weakened immune systems (from certain diseases or medical treatments) are more likely to develop many types of skin cancer, including melanoma. For example, people infected with HIV, the virus that causes AIDS, often have weakened immune systems and are also at increased risk for melanoma.
   
• Xeroderma pigmentosum (XP). XP is a rare, inherited condition that lowers skin cells’ ability to repair damage to their DNA. People with XP have a high risk of developing melanoma and other skin cancers when they’re young, especially on sun-exposed areas of their skin.

Screening

Most melanomas are brought to a doctor’s attention because of signs or symptoms a person is having. If you have an abnormal area on your skin that might be cancer, your doctor will examine it and might do tests to find out if it’s melanoma, another type of skin cancer or some other skin condition.