Cutaneous malignant melanoma
Unrepaired DNA damages skin cells triggering mutations, causing skin cells
to multiply rapidly and form malignant tumors. Curable if detected early,
but each year in the U.S. ~10,000 people die of this type of cancer.
In the lower epidermis, melanocytes produce melanin, the pigment that gives
skin its color. Exposed to the sun, melanocyes make more pigment causing skin to
darken.
Causes of melanoma skin cancer
- Excessive UV-B
exposure from sunlight causes all three skin cancer types.
- Excessive UV-A
exposure from sunlight. Now known to cause damage to proteins
and lipids and DNA lesions by indirect (and possibly direct mechanisms), leading
to carcinogenesis (Including cutaneous malignant melanoma) and aging skin.
Link
Symptoms of melanoma skin cancer
- These are the signs to look for when examining tumors,
which may indicate melanoma:
- Asymmetrical: a line drawn
through the middle of a tumor produces relatively similar halves;
- Border: irregular or jagged,
not smooth or ragged
- Multicolored: A combination
of colors is usual, one color tumors are probably OK
- Diameter > 1/4 inch:
non-malignant skin cancers tend to be smaller
- Evolving: Changes in elevation,
size, color, crusting, bleeding, itching, or anything else