Malignant melanoma should be suspected if there is a change in an existing mole, or if a new mole-like lesion develops. Irregularities in shape or color are hallmarks of a melanoma lesion Figure 01. Although lesions of malignant melanoma can arise anywhere on the body, they most commonly develop on the upper back of both men and women, and on the legs of women.
You can tell the difference between a normal mole and one that could be more dangerous by using the “ABCDE” rule. The letters A, B, C, D, and E stand for different aspects of mole appearance that serve as warning signs that your mole may be cancerous.
A is for asymmetry. See a doctor if your mole has an uneven shape, as opposed to an even, round, or oval shape.
B is for border. See a doctor if your mole has a jagged or ill-defined border.
C is for color. See a doctor if your mole has many colors, of if the color is not uniform.
D is for diameter. See a doctor if you have a mole that is larger than 6 mm (.24 inches, or about the size of a pencil eraser).
Later features of melanoma include an increase in height of the lesion, as well as crusting, bleeding, or pain.
Occasionally melanomas may lack pigment, or may lack the ABCD features.
Figure 01. Malignant Melanoma
Most cases of malignant melanoma occur in light-skinned individuals who have had excessive sun exposure. Other risk factors are excessive exposure to ultraviolet (UV) radiation, the presence of a giant birthmark or multiple moles, family history of melanoma, and a previous diagnosis of melanoma. Those who have had excessive exposure to ultraviolet (UV) radiation are particularly at risk, including those who suffered severe sunburns in childhood and adolescence, and people who underwent long-term UV light-based therapy (PUVA) for their psoriasis.
People who burn easily are most susceptible; especially individuals with freckles, blond or red hair, and blue or gray eyes. Individuals with multiple moles also have an increased risk. While other skin cancers tend to occur in the elderly population after a lifetime of accumulated sun exposure, melanoma is becoming increasingly common in younger people: 25% of tumors occur in patients younger than age 40.
Blacks are less likely to get melanoma than whites, but when they do, the cancer tends to be more aggressive, and mortality rates are increased. Dark-skinned individuals tend to get melanoma in places that are not exposed to the sun, including the palms of the hands, soles of the feet, mucous membranes, and under the nails.
Some genetic factors have been identified that increase susceptibility to melanoma. Family members of melanoma patients are deemed to be at higher risk. Large, congenital birthmarks(>8 inches, or about the size of an adult hand) are clearly associated with an increased risk. While malignant melanoma is rare in children, about half the cases that do occur in childhood arise from these giant birthmarks. The risk connected with smaller congenital moles is more controversial, and some doctors recommend monitoring them carefully rather than removing them.
People with the genetic condition known as atypical mole syndrome have numerous atypical moles, and tend to develop melanoma at a younger age. Atypical moles have an irregular surface, a mixture of colors, and ill-defined borders.
People who have had malignant melanoma once are at increased risk for developing a second primary tumor later in their lives. A primary tumor is the beginning site of a cancer, in contrast to secondary sites that become cancerous as the result of the cancer spreading.
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