Melanoma is a type of skin cancer that begins in the melanocytes. Melanoma usually begins on skin that is often exposed to the sun. This includes the skin on the arms, back, face, and legs. Melanoma can also form in the eyes, and it can also occur inside the body, such as in the nose or throat. The exact cause of all melanomas is unknown. Most melanomas are caused by exposure to ultraviolet light. the risk of developing melanoma appears to be increasing in people under 40, especially women. Knowing the symptoms of skin cancer can help ensure that the cancer is detected and treated before it spreads. If caught early, melanoma can be successfully treated.
Typical Features - Moles
Usually uniform in color. Most moles begin to appear in childhood and new moles don't appear until about age 40. By the time they reach adulthood, most people have between 10 and 40 moles. Moles may change in appearance over time, and some may even disappear with age.
Signs that may indicate melanoma
Some moles are not typical. They may have certain features that indicate melanoma or other skin cancers. Features may include.
Asymmetrical shape: for example, the two halves look very different.
Variations in color: Growths that have many colors or unusual color patterns.
Changes in size: New growths occur in moles larger than 1/4 inch (about 6 millimeters).
Changes in symptoms: such as new itching or bleeding.
Unusual borders: notched or scalloped borders.
Moles that turn into cancer all look very different. Some may show all of the changes listed above, while others may have only one or two unusual features.
Hidden Melanoma
Melanoma may also occur in areas of the body that receive little or no sunlight. These areas may include the spaces between the toes and palms of the hands, the soles of the feet, the scalp, or the genitals. These are sometimes called hidden melanomas because they occur in places that most people wouldn't think to check.
Occult melanomas include.
Melanoma in the body: e.g., mucosal melanoma occurs in the mucous membranes. This tissue lines the nose, mouth, esophagus, anus, urethra, and vagina. Mucosal melanomas are especially difficult to detect and can easily be mistaken for other, more common diseases.
Melanoma in the Eye: Melanoma of the eye is also known as ocular melanoma. It most often occurs in the layer of tissue below the white of the eye. Ocular melanoma may cause changes in vision and may be diagnosed during an eye exam.
Melanoma under the fingernails (toenails): Extremity pigmented melanoma is a rare type of melanoma that can occur under the fingernails or toenails. It can also be found on the palms of the hands or soles of the feet. Small scaly melanomas of the extremities are usually very dark, flat, and have very unusual borders.
Risk Factors
Factors that may increase the risk of developing melanoma include.
A family history of melanoma: People with close relatives such as parents, children, or siblings with melanoma have a greater chance of developing melanoma.
History of sunburns: One or more severe sunburns can increase the risk of developing melanoma.
Exposure to UV rays: UV rays from the sun, tanning lamps and beds increase the risk of developing skin cancer, including melanoma.
Having many moles or atypical moles: If you have more than 50 typical moles on your body, you are at increased risk for melanoma. In addition, there is an atypical mole that increases the risk of melanoma. Medically known as dysplastic moles, these tend to be larger than typical moles. They may have unusual borders and mixed colors.
Near the equator or at a higher elevation: people who live near the Earth's equator receive more direct sunlight. As a result, they are exposed to more UV rays than those living in the north or south. In addition, people who live at higher altitudes are more susceptible to UV exposure.
Sunburn-prone skin: Anyone can get melanoma, but it is most common in fair-skinned people. People with features such as blonde or red hair, light-colored eyes, and a tendency to freckle or sunburn are more likely to develop melanoma.
Weakened immune system: If the body's immune system, which fights bacteria, is weakened by medication or disease, the risk of developing melanoma and other skin cancers may be higher. People with weakened immune systems include those who take medications to control their immune systems, such as after an organ transplant. Certain diseases, such as HIV infection, can weaken the immune system.
