Melanoma

Melanin is a protein produced by cells known as melanocytes; they are what determine skin color. The function of melanin is to protect the skin by absorbing ultraviolet rays; this is manifested as a darkening of the skin, or a "suntan." People of African and Indian ancestry as well as those from Southeast Asia and other dark-skinned people produce much more of this substance, whereas people of northern European ancestry produce very little; this is why pale-skinned people tend to burn easily. It is also why they are far more susceptible to skin cancer, or melanoma. This disease accounts for just over 1% of all cancer deaths.

Risk Factors

Those most likely to contract malignant melanoma include those who:

have multiple irregular moles
a family history of such moles
skin disorders
are out in the sun too often
have freckles
have had frequent sunburn
are light-skinned and have blue eyes

To date, asbestos exposure is not known to be linked to melanoma. Asbestos expsosure is, however, one of the main causes of mesothelioma. If someone has been exposed to asbestos he/she may be receive a diagnosis of one of several types of mesothelioma including pleural mesothelioma, peritoneal mesothelioma, epithelial mesothelioma, sarcomatoid mesothelioma and pericardial mesothelioma.

Pathology

Melanoma begins on the outside, but over time works its way beneath the skin, entering the bloodstream and the lymph ducts, where it can spread to virtually any part of the body. This is why malignant melanoma is so dangerous.

The good news is that when caught in its earliest stages, melanoma is the easiest form of cancer to treat.

Signs and Symptoms

Melanomas can appear almost anywhere on the surface of the skin, but most frequently starts on the back or on the legs. Warning signs of malignant melanoma include:

a brown birthmark or irregular mole
a new, unusual freckle or mole
an asymmetrical dark area that grows in size and/or changes shape and begins to swell
dark areas that cause itchiness or sensitivity with a tendency to bleed easily
oozing and inflammation

Interestingly, this is one type of cancer that the immune system will attack, though it is usually unsuccessful. This is indicated by a white ring around the spot.

Diagnosis

Because a mole or irregular dark patch on the skin can be indicative of any number of conditions (or none at all), it is especially important that a biopsy (tissue sample) be sent to a qualified dermatologist for analysis.

Sources

Duff, Carol. "Melanoma: Skin Cancer That Kills." Veterans Today, 6 April 2009.

Holly, F.A. et. al. "Intraocular Melanoma Linked to Occupations and Chemical Exposures." Epidemiology, vol. 7 no. 1 (January 1996).