This is a malignant tumour of melanocytes, which are the melanin and pigment producing cells in the basal layer of the epidermis. It is by far the most dangerous and life-threatening form of all cancers. Two-thirds of all skin cancer deaths are attributable to it. Like other skin cancers, the frequency of melanomas appear to be increasing—and not because of better or earlier recognition.
Causes. The incidence is greatest where light-skinned Caucasians are exposed to large amounts of solar radiation. Unlike S.C.C.s or B.C.C.s, melanomas are not found predominantly on sun-exposed areas—one-third of tumours occur on the trunk. The greatest incidence in the world is in Queensland.
Occasionally a mole may undergo malignant change and become a melanoma. However, considering the number of moles in the population, this happens relatively rarely; melanomas of this origin account for probably less than one-third of melanomas.
Features. Melanomas may vary considerably in appearance. However they usually all have some degree of colour or pigmentation to them. This is usually not uniform, and the edges are commonly irregular. The pigmentation may range from tan through blue to black, or from between red and brown to blue and black. Sometimes a melanoma is quite flat and flush with the skin surface, or on the other hand it may appear as a raised lump.
Some of the characteristics that may be observed in a mole which should arouse suspicion are:
colour change—either becoming darker or more variable in colour size change—becoming larger or irregular in outline surface roughness, scales, ulceration, or bleeding itching or pain
Treatment. The treatment for melanomas is basically surgical excision. If the diagnosis is uncertain, this should be preceded by a biopsy. The surgery of melanomas is usually fairly extensive (that is! wide and deep) because of the poor prognoses for advanced cases. Usually, a fairly large margin of normal skin is taken out with the melanoma, and a skin graft applied. The more radical approach of the past, in which the lymph glands close to the affected skin were also removed, is no longer practised.
*110\44\4*
Category Skin Care | 0 Comments »