How can melanoma be recognized? Explanation of the ABCDE rule

2026-09-15

Melanoma is a malignant skin tumour arising from melanocytes, the early detection of which is of critical importance for successful treatment. The most widespread clinical and self-examination tool for identifying suspicious skin lesions and naevi is the so-called ABCDE rule. This acronym designates the following clinical warning signs: "A" (Asymmetry): one half of the lesion does not match the other in shape; "B" (Border): the borders are irregular, scalloped, or blurred; "C" (Color): the pigmentation is uneven, exhibiting multiple shades (shades of brown, black, reddish, bluish, or white areas); "D" (Diameter): the diameter of the lesion exceeds 6 millimetres (although early or small-diameter melanomas may be smaller than this); "E" (Evolution): rapid or gradual changes in the size, shape, or colour of the lesion, or newly emerging symptoms (such as elevation, itching, or bleeding). In clinical practice, the accuracy of the diagnosis is ensured by dermatoscopy and specialist examination, and, in cases of suspicion, by histological excision.

The ABCDE criteria system is a triage tool developed for naked-eye examination, which is applied in conjunction with the "ugly duckling" sign and dermatoscopic analysis. According to literature data, morphological change occurring over several months or weeks (Evolution) and colour variegation possess prominent predictive value in differentiating a malignant process, whereas in the case of nodular melanomas, the EFG rule (Elevation, Firm, Growing) serves as an additional criterion assisting early identification.

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