Dermatology Case Studies

Clinical Assessment of a Lesion

He has attached a photograph of the mole:

Figure 9: Brown, circular lesion with fading borders

You assess this photograph according to the ABCDE criteria, a very useful system for examining most skin lesions

Click each of letters of the mnemonic to reveal the assessment:

A is for Asymmetry

A melanocytic nevus (benign mole) is usually symmetrical, whereas melanoma is often irregular or asymmetrical in shape and/or colour
In this case you can clearly see the mole is symmetrical

B is for Border irregularity

In this case you can clearly see the photograph shows a mole with a smooth border

C is for Colour variability and/or Changing colour

A melanocytic nevus (benign mole) usually has a single shade of colour or two colours with one occurring inside the other or regularly repeated (generally pink, brown, or tan)
You can clearly see the regular colouring in the photograph the patient has submitted

D is for Different

Most people have a 'signature nevus' - all their melanocytic nevi resemble each other
A melanoma appears unique and very different from the patient's other lesions
A pigmented lesion that is obviously different from the others is sometimes called an 'ugly duckling', 'black sheep', 'lone ranger', or 'odd-mole-out' and must be considered suspicious even if it does not fulfil the ABCDE criteria
How similar this is to his other moles could be a useful question if you were seeing this patient face-to-face

E is for Evolving (changing)

A melanocytic nevus (benign mole) is usually stable and does not change in size, shape, or colour, whereas a melanoma changes over time
Change in size, colour, shape, or structure may be noted over months to years
In this case the patient is telling you that this mole has been there for a long time and has not changed as far as they can see
These are both reassuring points in the history