Back To CourseHuman Anatomy & Physiology: Help and Review
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Sarah has taught nursing courses and has a master's degree in nursing education.
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.
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.
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:
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.
This is the use of medicine to stimulate a person's own immune system to recognize and destroy cancer cells more efficiently. There are several types of immunotherapy available to treat people with advanced stage melanoma.
Some melanomas have specific gene changes that make the melanoma cells different from normal cells. Medications have been made to target and attack these changes. These medications work differently than chemotherapy and have less severe side effects. This is a newer form of treatment for melanoma and doctors are still learning about how to best use it.
This is the use of medications to kill cancer cells. The medication is usually given intravenously (IV) or by mouth as a pill. The medication travels in the bloodstream to all areas of the body to attack and kill cancer cells that have already spread beyond the skin. Chemotherapy (chemo) is usually not as effective in melanoma as it is in other cancers, but it can relieve symptoms or extend survival for some people.
This is the use of high-energy rays or particles to kill cancer cells. An external beam focuses radiation from outside the body on the skin tumor. Radiation therapy is not often used to treat the original melanoma, but it is sometimes used after surgery where lymph nodes where removed to try to reduce reoccurrence of melanoma.
Radiation is often used to relieve symptoms caused by the spread of melanoma, especially to the brain or bones. Any treatment with the goal to relieve symptoms is called palliative therapy. This means the goal of therapy is not to cure the cancer but to help shrink the tumors and control some of the symptoms.
Melanoma is the most dangerous and deadly form of skin cancer. It can occur anywhere on the body, but is most likely to occur on sun-exposed areas. There are four different types of melanoma: superficial spreading melanoma, lentigo maligna, acral lentiginous melanoma and nodular melanoma. Stages range from 0, which means localized and has not spread, to IV, which means it has metastasized to other parts of the body. Symptoms of melanoma include asymmetry in moles, uneven borders, discoloration of moles or skin, size larger than 6mm, and evolving changes in the skin. There are several treatment options for melanoma, varying on the type and stage of disease. Treatment options include: surgery, immunotherapy, targeted therapy, chemotherapy and radiation therapy.
Medical Disclaimer: The information on this site is for your information only and is not a substitute for professional medical advice.
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Back To CourseHuman Anatomy & Physiology: Help and Review
20 chapters | 736 lessons
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