| Melanoma is the most common form of skin | | | | or enter the blood stream (lymphatic system), |
| cancer and skin cancer is the most common form | | | | whereby it will spread to their parts of the body |
| of cancer in the Western world. It begins in skin | | | | (metastasis) very quickly. The rate of metastasis |
| cells called melanocytes. | | | | is a deciding factor in how a doctor treats cancer. |
| Melanocytes are found under the skin, which is | | | | Melanoma occurs when melanocytes become |
| made up of two layers: the epidermis on the | | | | malignant. It can occur at any age, but chances |
| outside and the dermis below that. To be | | | | increase with age. Fair-skinned people are more |
| accurate, melanocytes are found in the lowest | | | | likely to develop it than dark-skinned people. In |
| levels of the epidermis, but not actually in the | | | | fair-skinned races, men tend to get it on the |
| dermis. These cells produce melanin, which affects | | | | torso and neck, whereas women get it on their |
| the epidermis' pigmentation, both natural skin | | | | calves (lower legs). Dark-skinned people rarely get |
| colour and because of exposure to the sun as in | | | | melanoma, but if they do, it is usually under the |
| tanning. | | | | finger and toe nails or on the soles of the feet or |
| Sometimes, a group of near-by melanocytes | | | | palms of the hands. When cancerous cells from |
| combine with a little local tissue to form a mole | | | | melanoma enter the lymphatic system and affect |
| (also known as a nevus; plural nevi). The average | | | | other organs, it is still attributed to melanoma. For |
| person has between ten and forty moles, which | | | | example, if the liver becomes affected by |
| usually appear before the fortieth birthday. They | | | | cancerous cells from melanoma, it is referred to |
| often fade or disappear with age. Moles are | | | | as metastatic melanoma, not liver cancer. |
| non-malignant (non-cancerous) and can be flat or | | | | Often, the first sign of melanoma is a change in |
| raised in shape and almost any colour. Usually, | | | | the size, shape, colour, or feel of an existing mole, |
| they are slightly darker than one's natural skin | | | | although it often first manifests itself with a new |
| colour. Dark skinned people tend to have more | | | | mole or moles. Self-diagnosis is not to be relied on |
| moles. | | | | - always seek professional advice if you have any |
| Cancer begins in cells where the normal cycle of | | | | concerns relating to your skin. However, it is wise |
| decay and replacement by regeneration has been | | | | to remember 'The ABCD of Melanoma', which |
| disrupted. In these circumstances, cells do not | | | | goes thus: |
| always die when they should and new cells are | | | | Asymmetry: the shape of one half of the mole is |
| produced needlessly. This, in turn, produces a | | | | not the same as the other half. |
| growth (also known as a tumor), which can be | | | | Border: the border or edges of the mole are not |
| either benign or malignant (ie cancerous or | | | | clearly defined; a bit ragged or the pigmentation |
| non-cancerous). | | | | 'leaks' into the surrounding skin. |
| Benign tumors can be surgically removed and | | | | Colouration: the mole is not uniformly of one |
| rarely return. They do not spread or affect | | | | colour, although it is not so important what that |
| surrounding tissue. Malignant tumors are cancerous | | | | colour is. |
| and can affect surrounding tissue and organs. In | | | | Diameter: there is a change in size or a new mole |
| these cases, cancerous cells can break away | | | | grows larger than 5mm in size. |
| from the primary tumor and affect other organs | | | | |