Melanoma (Skin Cancer) |
Melanoma is a disease of the skin in which cancer cells are found in the cells that colour the skin (called melanocytes). Melanoma usually occurs in adults, but it may occasionally be found in children and adolescents. Melanoma is not the commonest type of skin cancer, but is one of the most dangerous.
Your skin protects your body against heat, light, infection, and injury. It is made up of two main layers: the top layer (called the epidermis) and the inner layer (called the dermis). Melanocytes are found in the epidermis and they contain melanin, which gives the skin its color. Melanoma is sometimes called cutaneous melanoma or malignant melanoma. The term malignant means the ability of the cancer cells to spread through the body, which is what makes melanoma so dangerous.
The other more common types of skin cancer include basal cell cancer and squamous cell cancer, which begin in the basal or squamous cells of the epidermis. Melanoma is rising in incidence throughout the world, and is disproportionately high in New Zealand. The incidence of melanoma greatest in light-skinned populations.
Symptoms and Presentation
Like most cancers, melanoma is best treated when it is found (diagnosed) early. Melanoma can spread (metastasize) quickly to other parts of the body through the lymph system or through the blood.
A doctor needs to be consulted with immediately if you have any of the following warning signs of melanoma:
-change in the size, shape, or color of a mole;
-oozing or bleeding from a mole;
-or a mole that feels itchy, hard, lumpy, swollen, or tender to the touch.
Melanoma can also appear on the body as a new mole. Men most often get melanoma on the trunk (the area of the body between the shoulders and hips) or on the head or neck; women most often get melanoma on the arms and legs. If you have any suspicious changes of mole then you shouldnąt hesitate to have it examined by your physician.
Stages of Melanoma
In order to plan treatment for correctly, melanoma is staged. This may involve more tests to find out if cancer cells have spread to other parts of the body.
The following stages are used for melanoma:
In stage 0 melanoma, the abnormal cells are found only in the outer layer of skin cells and do not invade deeper tissues.
Cancer is found in the outer layer of the skin (epidermis) and/or the upper part of the inner layer of skin (dermis), but it has not spread to nearby lymph nodes. The tumour is less than 1.5 millimetres (1/16 of an inch) thick.
The tumour is 1.5 millimetres to 4 millimetres (less than 1/6 of an inch) thick. It has spread to the lower part of the inner layer of skin (dermis), but not into the tissue below the skin or into nearby lymph nodes.
Any of the following mean that the tumour is stage III:
1. The tumour is more than 4 millimetres (approximately 1/6 of an inch) thick.
2. The tumour has spread to the body tissue below the skin.
3. There are additional tumour growths within one inch of the original tumour (satellite tumours).
4. The tumour has spread to nearby lymph nodes or there are additional tumour growths (satellite tumours) between the original tumour and the lymph nodes in the area.
The tumour has spread to other organs or to lymph nodes far away from the original tumour.
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the original site or in another part of the body.See also: