What Is Melanoma? - Types, Stages, Symptoms & Treatment

Instructor: Sarah Lawson

Sarah has taught nursing courses and has a master's degree in nursing education.

Melanoma is the most dangerous and deadly form of skin cancer. Learn more about the types, stages, symptoms and treatment of melanoma, and test your knowledge with a quiz.

What Is Melanoma?

Are you a beach bum? Or a sun worshiper? Do you use tanning beds? If you answered 'yes' to any of these questions then you need to pay close attention to this lesson, as you may be unknowingly putting yourself in danger of developing skin cancer later in life.

Melanoma is skin cancer that develops when damaged DNA in skin cells causes mutations or genetic defects that lead skin cells to rapidly multiply and form malignant tumors. It is the most dangerous and deadly form of skin cancer. Melanoma is mainly caused by intense, occasional UV exposure (often provided by sunshine or tanning beds) that frequently leads to sunburn.

Melanoma develops in the pigment-producing melanocytes in the basal layer of the epidermis. It can resemble a mole or even develop from moles. Most melanomas are black or brown in appearance and are often asymmetrical. They can also be skin-colored, pink, red, purple, blue or white.

When melanoma is caught early, it is almost always curable. However, if it is not caught early and is allowed to spread, or metastasize, to other parts of the body, then it becomes much more difficult to treat and may be fatal. It is estimated that 120,000 new cases of melanoma will be diagnosed each year in the U.S.; approximately 9,710 of these cases lead to death.


There are four different types of melanoma cancer. Three of them begin 'in situ', which means they occupy and spread in the top layer of the skin and can become invasive. The fourth type is invasive from the start.

Superficial spreading melanoma is the most common of the melanomas. It is seen mostly in young people and accounts for 70% of all cases. It grows along the top layer of the skin for quite a long time before penetrating deeper layers. The first sign of this cancer is usually a flat or slightly raised discolored patch with irregular borders and asymmetrical shape. It can form anywhere on the body. It is most often found on the trunk in men and on the legs in women or on the upper back in both.

Superficial spreading melanoma
Superficial spreading melanoma

Lentigo maligna remains on the skin's surface for quite a long time before it spreads to the deeper layers. It also appears as a flat or slightly elevated discoloration that is usually tan, brown, or dark brown. It is most commonly found in the elderly on the face, ears, arms and upper trunk.

Acral lentiginous melanoma, like the two types discussed previously, spreads superficially before it penetrates deeper. However, it usually appears as a black or brown discoloration on the soles of the feet or palms of the hands. It can also appear under the nails on hands and feet. This type of melanoma is most common in African-Americans and Asians and least common in Caucasians.

Nodular melanoma is usually invasive at the time of diagnosis. It is recognized when it becomes a bump or lump. It is most frequently found on the trunk, legs, arms, and scalp in men. It is more common in elderly people. It usually appears as black but can also be blue, gray, white, brown, tan, red or skin tone. It is the most aggressive of the melanoma and accounts for 10 to 15% of all cases.

Nodular melanoma showing changes over time
Nodular melanoma showing changes over time


Once the diagnosis of melanoma has been made, the next step is to classify the disease on its level of severity. Classifications for melanomas and other cancers are called stages. The stage of cancer refers to the thickness, depth of penetration, and local of metastasis if present. Stages range from 0, which means localized and has not spread, to IV, which means it has metastasized to other parts of the body.

Stages 0 and I are early melanomas and are the most easily treated. They are localized and 'in situ', which means they have not penetrated to deeper layers of the skin. Stage I tumors have invaded the skin, but are small and growing at a slow rate.

Stage II tumors are still localized but are larger, usually over 1 mm thick. They are considered intermediate melanomas; meaning not advanced but not early stage either.

Stages III and IV and advanced melanomas and have spread, or metastasized, either to deeper layers of the skin or to other parts of the body.


There are many symptoms of melanoma. Most people need yearly skin checks to check for these symptoms, but groups at higher risk may need checks more frequently. It is also important for people to regularly examine their own skin, including moles. The following symptoms are the ABCDE's of melanoma:

  • A - asymmetry. If a line is drawn through the center of a mole, each half should look the same as the other. If this is not the case, then the mole is asymmetrical and needs to be looked at by a doctor.
  • B - border. The border of melanoma tends to be uneven. The edges may be raised or notched.
  • C - color. The color of a mole should be uniform throughout. If a mole has darker areas than others or the color seems to be changing in any way, then it needs to be looked at by a doctor.
  • D - diameter. Melanomas are usually larger than the eraser on a pencil (1/4 in. or 6mm.).
  • E - evolving. Any change in a mole or other area of skin is a symptom or warning sign of melanoma. Changes in size, shape, color, or elevation need to be addressed. Also, other symptoms include bleeding, itching, or crusting.

Pictures of melanomas on the left vs. normal moles on the right
Pictures of melanomas on the left vs. normal moles on the right


Treatment options depend on the type of melanoma and the stage of disease. The following are different treatments used to treat melanoma:


With this treatment, an excision of the tumor will be made to remove it. The doctor will excise a small amount of healthy tissue on all sides of the excision to make sure all the melanoma tissue is removed.

Sometimes further surgery is necessary, especially in cases where the melanoma has spread. This may include deeper excisions or removal of nearby lymph nodes. If cancer has spread beyond the lymph nodes to other organs, it is unlikely that surgery can cure the cancer. Doctors may still perform surgery if tumors are painful or interfering with quality of life.

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