Melanoma is a cancer of the pigment producing cells in the epidermis, or upper surface of the skin. The incidence, or annual risk of developing this form of cancer, in the United States has been increasing each year. This cancer is believed to be a result of extensive exposure to the sun's radiation over a period of time. It is for that reason that the most common locations of this cancer are the exposed parts of the skin, particularly the face and neck.
Early diagnosis plays a most important role in controlling this form of cancer. It is for that reason that everyone should pay close attention to the appearance of moles on the skin for possible changes that might suggest transformation to a cancer.
These changes in the moles may be a thickening, scaling, itching, redness surrounding the mole, or bleeding. The American Cancer Society has adopted the "A B C D" warning signs to watch for:
Asymmetry - any changes in the uniformity of the shape of the mole.
Border - any irregularity in the margins of the mole, or blurring of the borders.
Color - various colors, with irregular shades of brown, blue, black, or loss of pigmentation of a portion of the mole.
Diameter - an increase in the size of a mole, with a diameter greater than 6 millimeters, or a quarter of an inch (size of eraserhead of a pencil).
There are four variants of melanoma. The lentigo maligna melanoma is a very flat and thin variant of the cancer, frequently presenting as a large freckle. The superficial spreading melanoma is also flat, or only slightly raised, and a bit more uniform in color. The nodular melanoma is an elevated and often rounded growth of the cancer. The acral lentigenous melanoma occurs on the palms and soles of the hands and feet, or in the cuticles or nail bed. The desmoplastic melanoma does not often produce pigment and is therefore the most difficult to diagnose without a biopsy examination.
It is very important to have all changing moles and growths examined by a physician so that the suspicious ones can be removed and examined under the microscope. All tumors that are diagnosed to be melanomas will require a wider re-excision of the skin at the location of the tumor, and an evaluation of potential spread to the local lymph nodes.