Intended for healthcare professionals

Difficult to diagnose melanomas

For years, dermatologists have been evaluating skin lesions by means of analytical examination, pattern recognition, comparative analysis and dynamic analysis.1 Pattern recognition is by far the most commonly used method to identify melanoma skin cancers, and this can often be done in seconds by an experienced clinician.

There are various clinical prediction rules to help doctors diagnose melanomas, including the popular ABCDE criteria (Asymmetry, border irregularity, Ccolour variation, diameter greater than 6mm and evolution in size, shape or colour); the ‘ugly duckling sign’ which is a comparative analysis used to spot a pigmented skin lesion that differs from the patient’s signature naevi; and the Glasgow sevenpoint checklist used by patients and GPs to detect and score features indicating possible melanoma, prompting urgent referral with a score of =3.2,3 While these diagnostic aids can be useful, they generally apply to superficial spreading malignant melanoma (the most common type – 70% of all melanomas) and not the less common melanoma variants.2

It has been estimated that the sensitivity and specificity to diagnose a melanoma with the naked eye by an experienced dermatologist is 70% and 80% respectively.2 The introduction of diagnostic aids like dermoscopy has increased our sensitivity to diagnose melanomas by 10-27% compared to the use of unaided trained eye alone.1 Despite its measurable advantage, dermoscopy remains a subjective tool relying heavily on morphological appearance, and may not diagnose 10% of melanomas if used in isolation without a detailed history.


Dermatology in practice 2022; 28(1): 4–7
To continue reading this article, please sign in or register.