User:Mr. Ibrahem/Melanoma
Medical condition / From Wikipedia, the free encyclopedia
Melanoma, also known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes.[1] Melanomas typically occur in the skin but may rarely occur in the mouth, intestines or eye (uveal melanoma).[1][2] In women, they most commonly occur on the legs, while in men they most commonly occur on the back.[2] About 25% of melanomas develop from moles.[2] Changes in a mole that can indicate melanoma include an increase in size, irregular edges, change in color, itchiness or skin breakdown.[1]
Melanoma | |
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Other names | Malignant melanoma |
A melanoma of approximately 2.5 cm (1 in) by 1.5 cm (0.6 in) | |
Pronunciation | |
Specialty | Oncology and dermatology |
Symptoms | Mole that is increasing in size, has irregular edges, change in color, itchiness, or skin breakdown.[1] |
Causes | Ultraviolet light (Sun, tanning devices)[2] |
Risk factors | Family history, many moles, poor immune function[1] |
Diagnostic method | Tissue biopsy[1] |
Differential diagnosis | Seborrheic keratosis, lentigo, blue nevus, dermatofibroma[3] |
Prevention | Sunscreen, avoiding UV light[2] |
Treatment | Surgery[1] |
Prognosis | Five-year survival rates in US 99% (localized), 25% (disseminated)[4] |
Frequency | 3.1 million (2015)[5] |
Deaths | 59,800 (2015)[6] |
The primary cause of melanoma is ultraviolet light (UV) exposure in those with low levels of the skin pigment melanin.[2][7] The UV light may be from the sun or other sources, such as tanning devices.[2] Those with many moles, a history of affected family members and poor immune function are at greater risk.[1] A number of rare genetic conditions such as xeroderma pigmentosum also increase the risk.[8] Diagnosis is by biopsy and analysis of any skin lesion that has signs of being potentially cancerous.[1]
Using sunscreen and avoiding UV light may prevent melanoma.[2] Treatment is typically removal by surgery.[1] In those with slightly larger cancers, nearby lymph nodes may be tested for spread (metastasis).[1] Most people are cured if spread has not occurred.[1] For those in whom melanoma has spread, immunotherapy, biologic therapy, radiation therapy or chemotherapy may improve survival.[1][9] With treatment, the five-year survival rates in the United States are 99% among those with localized disease, 65% when the disease has spread to lymph nodes and 25% among those with distant spread.[4] The likelihood that melanoma will reoccur or spread depends on its thickness, how fast the cells are dividing and whether or not the overlying skin has broken down.[2]
Melanoma is the most dangerous type of skin cancer.[2] Globally, in 2012, it newly occurred in 232,000 people.[2] In 2015, there were 3.1 million people with active disease, which resulted in 59,800 deaths.[5][6] Australia and New Zealand have the highest rates of melanoma in the world.[2] There are also high rates in Northern Europe and North America, while it is less common in Asia, Africa and Latin America.[2] In the United States melanoma occurs about 1.6 times more often in men than women.[10] Melanoma has become more common since the 1960s in areas mostly populated by people of European descent.[2][8]