Why skin cancer screening intervals should be individualised

Melanomas reflect the chaotic growth of malignant cells, which is why dermatoscopic chaos (asymmetry of structure and/or colour) and other clues become increasingly apparent as they grow.

This chaotic behaviour can also be apparent in the clinical appearance because malignant skin lesions can ‘break the pattern’ when compared to other lesions in their proximity.

They can be different in shape and colour and eventually in their size, because there are no feedback mechanisms to shut down their continued growth.

This has led to metaphors such as the ‘ugly duckling sign’