Malignant melanoma is a serious form of cancer that develops from melanocytes, normally in skin.
Early diagnosis and treatment with excision improves survival. The commonest and most important danger signals are growth and colour change, particularly the development of black areas. Special attention should be paid to pigmented lesions that differ from others in their appearance or development, often called the ugly duckling sign. The ABCDE rule (Box 1) is somewhat more complicated, and most relevant for health personnel (6, 7). The rule is based on the fact that most malignant melanomas are Asymmetrical, have an irregular Border, Colour variation with black parts, a Diameter of over 6 mm, and additionally that they have Evolving. The ABCDE rule is appropriate for identifying many cases of melanoma, but less so for nodular varieties: these have a symmetrical shape and also the poorest prognosis (8).
The ABCDE rule
There are a number of signs that may distinguish a malignant melanoma from a benign pigmented naevus. These signs can be compiled into the ABCDE rule (7)
Asymmetry (two parts of the mole have different shapes)
Border (uneven border on the mole)
Colour (colour variation, often with black parts in the mole)
Diameter (mole is over 6 mm in diameter)
Evolving (the mole grows, or changes in some other way as described in the points above)
If a doctor suspects, or cannot exclude the possibility of a diagnosis of malignant melanoma, the lesion should be excised in its entirety with at least 2 mm free margin, either with a punch (Video 2) or by means of an elliptical excision (Video 3). These are procedures that all GPs be competent in. If they are not, the patient must be referred with a clear and unambiguously formulated reference to a dermatologist or surgeon, who should see the patient within two weeks at the latest (9).