Dermoscopic photography: Zooming in to detect skin cancer clues

We take dermoscopic photos of atypical skin lesions: suspicious, unusual-looking or “ugly duckling” spots. These spots don’t look like typical skin cancers, but we must consider the possibility that they are.

Improved assessment of your skin lesion

A high-magnification dermoscopic photograph allows better evaluation and diagnosis during your consultation:

• Your doctor can spend longer looking at and assessing the spot.
• The photo can be analysed using an AI algorithm, which provides a “second opinion”. This algorithm has been shown to be as accurate as a dermatologist in certain situations (Esteva 2017).

Sequential dermoscopic photography

If your doctor decides that the spot is unlikely to be a skin cancer, but can’t confidently rule out the possibility, you should return to the clinic to have a further photograph taken of the spot in 3 months. This enables us to check for changes that might indicate that the spot is a skin cancer.

If there is no significant change:

• If the photos show no significant change in your skin lesion, then it is unlikely to be a skin cancer.
• This means we have avoided an unnecessary biopsy or excision procedure and any associated costs, scarring and other side effects.
• Studies have shown that sequential dermoscopic photography significantly reduces the number of normal moles that are removed (Menzies 2018).

If the skin lesion changes:

• If the skin lesion changes in the interval between photographs, this can sometimes be a sign that it’s a skin cancer. In this event, your doctor may decide to perform an excision biopsy to establish the diagnosis.

This applies for melanomas detected:

• By the patient or someone they know (Salerni 2014)
• By a doctor who has not performed sequential photography (Rademaker 2010, Menzies 2018)

You have access to your photos

Your photos are stored in the DermEngine/MoleScope system, which means you have access to them. If you take your own dermoscopic photos using a magnifying attachment, you have the opportunity to detect skin cancers yourself much earlier than you would otherwise.

If you have your skin checked at another skin clinic in future, you can provide your photos to your new clinic, to give them the opportunity to diagnose skin cancers.

Warnings

Dermoscopic photography significantly increases the ability of the doctor to diagnose early melanoma. However, it is still possible for melanoma and other skin cancers to be missed even with dermoscopic photography repeated at the recommended interval: a low-risk appearance on dermoscopic photography does not always rule out skin cancer. The best way of diagnosing skin cancer is a skin biopsy, which should be performed if there is a reasonable suspicion of skin cancer.

References

Esteva A, Kuprel B, Novoa R, Ko J et al Dermatologist-level classification of skin cancer with deep neural networks. Nature volume 542, pages 115–118. 2017

Salerni G, Terán T, Alonso C, Fernández-Bussy R The role of dermoscopy and digital dermoscopy in the clinical diagnosis of melanoma: clinical and dermoscopic features of 99 consecutive primary melanomas. Dermatology Practical and Conceptual 2014

Rademaker M, Oakley A Digital monitoring by whole body photography and sequential digital dermoscopy detects thinner melanomas. Journal of Primary Health Care 2(4) 268 – 272, 2010.

Menzies S, Guitera P, Soyer P et al What is the role of sequential digital dermoscopy imaging in melanoma diagnosis? Clinical practice guidelines for the diagnosis and management of melanoma, 2018.