Definition
Malignant melanoma is a type of cancer arising from the melanocyte cells of the skin. The melanocytes are cells in the skin that produce the pigment melanin. Malignant melanoma develops when the melanocytes no longer respond to normal control mechanisms of cellular growth and are capable of invasion locally or spread to other organs in the body (metastasis), where again they invade and compromise the function of that organ.
Description
Melanocytes, embryologically derived from the neural crest, are distributed in the epidermis and thus are found throughout the skin. They produce a brown pigment known as melanin and are responsible for racial variation in skin color and also the color of moles. Malignant degeneration of the melanocyte gives rise to the tumor, melanoma, of which there are four subtypes. These are: superficial spreading, nodular, lentigo maligna, and acral lentiginous melanomas, accounting for 70%, 15% to 30%, 4% to 10%, and 2% to 8% of cases, respectively. Malignant melanoma may develop anywhere on the body. In men, it is most common on the trunk. In women, it is most common on the back or legs. The subtype also may influence where the tumor develops, lentigo melanoma is more common on the face while acral lentiginous melanoma is more common on the palms of the hand, soles of the feet, or in the nail beds.
The locally invasive characteristic of this tumor involves vertical penetration through the skin and into the dermis and subcutaneous (under-the-skin) tissues of the malignant melanocytes. With the exception of the nodular variety of melanoma, there is often a phase of radial or lateral growth associated with these tumors. Since it is the vertical growth that characterizes the malignancy, th...
... middle of paper ...
...r, et al. "NRAS and BRAF Mutations Arise Early During Melanoma Pathogenesis and Are Preserved Throughout Tumor Progression." Clinical Cancer Research 9 (December 15, 2003): 6483–6488.
Rockmann, H., and D. Schadendorf. "Drug Resistance in Human Melanoma: Mechanisms and Therapeutic Opportunities" Onkologie 26 (December 2003): 581–587.
Weinstock, Martin A. "Early Detection of Melanoma." JAMA, The Journal of the American Medical Association 284 (16 August 2000): 886.
Whiteman, D. C., P. Watt, D. M. Purdie, et al. "Melanocytic Nevi, Solar Keratoses, and Divergent Pathways to Cutaneous Melanoma." Journal of the National Cancer Institute 95 (June 4, 2003): 806–812.
Other
Cancer Resource Center American Cancer Society. [cited June 20, 2005]. .
Melanoma Patient's Information Page. [cited June 20, 2005]. .
National Cancer Institute. [cited June 13, 2005]. .
Melanoma is an extremely important issue, as 75% of skin cancer deaths in Australia are attributed to melanoma, making it the most dangerous form of skin cancer in the country (AIHW 2010). The AIHW also states that Australia has the highest occurrence of melanoma in the world, with over 12,500 Australians being diagnosed annually, and having a recorded 1500 deaths each year. The Melanoma Institute of Australia states that melanoma is the “most common cancer in young Australians aged 15-39”, and that “rates have doubled in the 20 years from 1986-2006”. The incidence of melanoma is increasing more rapidly than any other major cancer. Owing to the high incidence and mortality rates of the disease in Australia, melanoma is the most life-threatening form of skin cancer in the country, making it a very serious non-communicable disease.
What is skin cancer ? first, Skin is the largest organ of the body . it gives our body protection from harms, injuries and infections. It also organize the body temperature and dispose of waste substances through the glands . out layer of the skin is called the epidermis and the layer underneath is known as the dermis . Skin cancer is type of disease where malignant cancer cells are to be found the outer layer of a person's skin and is the uncontrolled development of the irregular skin cells .It occurs when unrepaired DNA damage to skin cells caused by ultraviolet radiation from sunlight or genetic defects, that lead the skin cells to duplicate rapidly and form malignant tumors. there are three main types of skin cancer which are basal
Malignant Melanoma is a type of malignant cancer that affects the melanocytes. A melanocyte produces the pigmentation in our skin and melanin gives us the color to our skin. These cells occur in the skin and can be found in other parts of the body. It is important to realize that melanoma can begin in any part of the body that can contain a melanocyte. Melanoma is considered less common than other skin cancers. It is a cancer that can be very dangerous if not detected early. Although in most cases it is diagnosed in time and can be cured. Many people are diagnosed with this cancer and it is said that 160,000 cases are diagnosed a year. ( ). In men a common site is on their back and for a woman is on their legs.
Superficial spreading melanoma spreads slowly on the top layers of the skin before it may begin to penetrate deeper layers of skin. A flat or slightly raised, discolored (tan, brown, black, red, blue or white), and asymmetrical patch of skin. are likely indicators of its presence. In this regard, superficial spreading melanoma may begin with previously benign mole. This type of melanoma is more common in young people, and it accounts for 70 percent of all melanoma diagnosis.
Polsky, David, MD, and Steven Q. Wang, MD. "Skin Cancer Facts." Skincancer.org. Skin Cancer Foundation, 9 Oct. 2013. Web. 23 Apr. 2014.
Cancer has been an active concern in our society for the past couple decades, since we truly discovered the nature of cancer and the potency it brings along with it. However, it was not until the mid-20th century that scientists were beginning to truly understand the origin of cancer. Scientists dating back all the way to the Renaissance, when they first began performing autopsies to learn more about the human body and form, noticed abnormalities but it never clicked that it was something much worse than it seemed. Research has continued since then, and it has continued to thrive even to this day. When James Watson and Francis Crick discovered DNA and it’s chemical structure in 1962, it opened up doors that even they could not expect. With the understanding of DNA and how it affected the way we look at life, came the beginning of the understanding of mutated DNA (which is a cause of the growth of cancerous cells). In this past century, researching scientists discovered that cancer is linked with the DNA that resides in a cell’s nucleus. By ways of damage to the cells via chemicals or radiation, or even introduction of a new DNA, the cancerous cells begin to form and duplicate. We are learning more and more about cancer and how to fight it, but we still have much more to learn.
The most common type of skin cancer is nonmelanoma skin cancer, which is classified as basal cell carcinoma or squamous cell carcinoma. “These begin either in the basal cells or squamous cells that are located at the base of the outer layer of the skin.” (Kenneth, 2012) Basal and squamous cell cancers are among the less serious types of skin cancers, but make up ninety-five percent of all skin cancers.
Outward appearances along with genetics have a lot to do with chances of receiving melanoma. Fair skinned individuals with either blonde or red hair with blue or green eyes are more susceptible to get skin cancer. If one is to have close relatives who have been diagnosed with skin cancer this puts individuals at a higher risk. If you live at high altitudes, live in sunny areas (nearest the equator), have had one or more blistering sunburns during childhood, and use tanning devices this puts a person at rick for melanoma skin cancer. Certain types of moles and birthmarks may become cancerous.
Basal and squamous cell skin cancer are the most common forms of skin cancer. Multiple studies have shown that these cancers are almost always connected to large amounts of sun exposure. This can come from things like outdoor sports, performing something outdoors with little coverage from clothing, and getting multiple severe sunburns. You can see signs of skin cancer inside and outside of your body. Rough, thick, dry skin patches are common symptoms, but things
Imagine that you are sixteen. You are overjoyed because you have just received your license and can finally drive whenever and wherever you please. A lot of people have been talking about the new tanning salon that has recently opened up in town. You decide to go and check it out, and discover that tanning is something you really enjoy. Tanning becomes an every-other-day occurrence, but after a year, you notice a mole on your leg that you never noticed before. The mole is cancerous, and it is melanoma. You have cancer, and you are only a teenager.
Many studies and research has gone into Tasmanian devil facial tumor disease, focusing on how it originated, how it is spread between the species, why it is so harmful and life threatening to the largest extant marsupials living, and what scientists are doing to stop it. Even though it seems like a simple disease to be taken care of, the overall effects of the disease are much more complex and life threating than they seem. There has been a dramatic loss in genetic diversity throughout the years since the disease originated. This paper will compare McCallum’s (2008), Miller et al.’s (2011), and Murchison’s (2008) research and studies on the comparison of other life threatening transmissible diseases, genetic diversities, origin of the disease, effects and transmission of the disease, and the endangerment of this marsupial.
Human pigmentation is influenced by hemoglobins within blood vessels in the skin, carotene and melanins. Melanin, the basis of pigmentation, can be found in the forms of eumelanin and phaeomelanin. Eumelanin is the brown-black pigment located in the skin, hair, and eyes. Phaeomelanin is a yellow to reddish-brown pigment found in small quantities within the skin, eyes, and red hair. Because of these two pigments, to a greater or lesser degree, we have the variation in human pigmentation that is seen today.
Skin cancer is a disease where cancer (malignant) cells are found on the outer layer of the skin (epidermis). The three types of cells found in the epidermis are squamous cells, basal cells, and melanocytes. These cells in time grow to be cancerous. Thus, the three types of skin cancers are squamous cell, basal cell, and melanoma. Melanoma is the most deadliest and destructive type of cancer. (“Skin Cancer” infotrac.com) The number of people with melanoma has risen in Scotland from 3.5 in 1979 to 10.6 per 100,000 in 1998 for men and 7.0 to 13.1 for women. (Miller 945) Squamous cell and Basal cell skin cancer can kill up to 2,200 people a year in the United States. (Sommerfield SIRS.com) Basal cell, being the most common type of skin cancer, is the cancer that about 75 percent of the people have. (“Skin Cancer “ infotrac.com) Melanoma is mostly seen in older men but ever since tanning came in during the 1970’s, it has increased in women 60 percent around the ages 15-29 over the past three decades.(Sommerfield SIRS.com) “And basal cell and squamous cell cancers are increasing at a rate of about 5 percent per year”(Sommerfield SIRS.com).
The first sign of melanoma is often a change in the size, shape, or color of an existing mole or the appearance of a new mole. Men most commonly develop melanoma on the trunk, particularly the back, and women on the legs or arms. Melanoma develops in a manner similar to other cancer types. A cell's DNA genes, which control cell division and reproduction, become damaged. The damaged genes cause the cell to divide and grow without control or order, eventually becoming a malignant tumor.
5.) Mylonakis, M.D., Eleftherios. PPD skin test. 10 June 2006 MedlinePlus. 26 July 2006 .