The most dangerous form of skin cancer, these cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by exposure to the harmful ultraviolet rays from the sun or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumors. These tumors originate in the pigment-producing cells in the superficial layer of the skin called the epidermis. Melanomas often resemble moles; some develop from moles. The majority of melanomas are black or brown, but they can also be skin-colored, pink, red, purple, blue or white. Melanoma is caused mainly by intense, repeated exposure to the harmful ultraviolet sun rays, especially common among people who tan until they get a sunburn.
If melanoma is recognized and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths.
Moles, brown spots and growths on the skin are usually harmless — but not always. Anyone who has more than 100 moles is at greater risk for melanoma. The first signs can appear in one or more atypical moles. That’s why it’s so important to get to know your skin very well and to recognize any changes in the moles on your body. An easy system to remember in order to catch a melanoma early uses the ABCDE signs.
Assymetric – Melanomas are generally assymetric in shape as opposed to moles that are more or less symmetric.
Borders of melanomas are usually not well defined, compare the left picture with the right to see the difference between a benign lesion (right) and malignant melanoma(left).
Diameters of melamoas are generally greater than 6 millimeters or the size of a pencil eraser.
Evolution is the most suspicious character of any malignant lesion. If there is a progressive change in the color, size, elevation or new symptoms like bleeding itching or crusting, the lesion is a melanoma until proven otherwise!
The first step in treatment is the removal of the melanoma, and the standard method of doing this is by surgical excision (cutting it out). Surgery has made great advances in the past decade, and much less tissue is removed than was customary in the past. Patients do just as well after the lesser surgery, which is easier to tolerate and produces a smaller scar.
Surgical excision is also called resection, and the borders of the entire area excised are known as the margins.
In most cases, the surgery for thin melanomas can be done in the doctor’s office or as an outpatient procedure under local anesthesia. Stitches (sutures) remain in place for one to two weeks, and most patients are advised to avoid heavy exercise during this time. Scars are usually small and improve over time.
Discolorations and areas that are depressed or raised following the surgery can be concealed with cosmetics specially formulated to provide camouflage. If the melanoma is larger and requires more extensive surgery, a better cosmetic appearance can be obtained with flaps made from skin near the tumor, or with grafts of skin taken from another part of the body. For grafting, the skin is removed from areas that are normally or easily covered with clothing.
There is now a trend towards performing sentinel node biopsy and tumor removal surgery at the same time, provided the tumor is 1 mm or more thick. When the procedures are combined in this way, the patient is spared an extra visit.
The margins taken around the melanoma are wider than those taken for other skin cancers. Expect the area of skin removed in order to treat a melanoma to be larger in diameter by 0.5 to 2cm than the actual lesion in order to obtain margins of skin that do not have melanoma cells.
When Melanoma has spread beyond its original site, other treatments may be offered including chemotherapy which employs medications that help to kill cancer cells, immunotherapy that includes drugs that help the patient’s immune system fight the melanoma and gene therapy which is currently in the experimental phase.