Mole check: how to detect skin cancer

A mole check involves examining the skin — both at home and at a clinic — to identify lesions that could indicate skin cancer. The key is to detect changes in time: when melanoma is found before it spreads, the vast majority of cases have a good outcome.

At Clínica Valorian in Marbella, Dr. Florian A. Vallecillo Cabrera applies an evidence-based medicine approach to skin health. This guide explains how to monitor your moles with informed criteria, which signs should alert you, and when to request a professional assessment.

The ABCDE rule for evaluating suspicious moles

The ABCDE rule is the simplest way to remember which signs turn an ordinary mole into one that deserves attention. It is not a tool for self-diagnosis, but it does help you decide when to seek medical advice. Each letter points to a specific characteristic:

• A for Asymmetry. If you draw an imaginary line through the centre, the two halves of a normal mole look similar. When one half does not match the other, it is worth paying closer attention.
• B for Border. Irregular, jagged or poorly defined edges are more suspicious than a clean, rounded outline.
• C for Colour. A single, uniform shade of brown is what is typical. A mixture of browns, blacks, reds, whites or blue-grey tones within the same mole is a warning sign.
• D for Diameter. Melanomas are usually larger than 6 millimetres — roughly the width of a pencil eraser — although smaller ones also exist.
• E for Evolution. Any change over time in size, shape, colour, texture, itching or bleeding is arguably the most important sign of all.

The "E" deserves special mention. A mole that changes — even if it does not meet the other criteria — is reason enough to seek a consultation. Your own memory of what your skin looked like months ago is a highly valuable screening tool.

Why early detection changes the prognosis

The reason we place such emphasis on checking moles is prognosis. According to the American Academy of Dermatology, the five-year survival rate for localised melanoma is 99% when it is detected and treated before reaching the lymph nodes. That figure drops to 76% when the tumour reaches nearby lymph nodes, and to 35% when it has spread to distant organs.

In other words: the same type of cancer carries very different prognoses depending on when it is discovered. That is where the value of examining your skin and attending regular check-ups lies. The goal is not to become alarmed by every spot. The goal is to give the specialist the opportunity to act early.

When and how often to have a dermatology check-up

For most people, an annual dermatology check-up is a reasonable benchmark. The frequency increases when risk factors are present. More frequent monitoring is worth considering if you identify with any of these profiles:

• You have many moles or atypical moles.
• Your skin is fair, prone to burning and with little ability to tan.
• There is a personal or family history of melanoma or other skin cancer.
• You have had significant sunburns, especially during childhood.
• You live or work in an area with high solar radiation for much of the year.

Between check-ups, any new mole that appears after the age of 30, or an existing one that changes, is reason to bring your appointment forward. It is not advisable to delay an assessment when you notice a lesion that does not quite fit in with the rest of your skin.

What dermoscopy is and why it improves diagnosis

Dermoscopy is a technique in which the doctor examines the skin using a dermoscope, an instrument with light and magnification that reveals structures within a mole that are invisible to the naked eye. It is painless, non-invasive and takes just a few minutes during the consultation itself.

Its advantage lies in precision. To the naked eye, two moles may look identical; under the dermoscope, pigment patterns, blood vessels and colour distribution provide information that helps distinguish benign lesions from suspicious ones. In the hands of a trained professional, dermoscopy reduces both unnecessary biopsies and the risk of overlooking a lesion that does warrant further investigation.

At Clínica Valorian we incorporate dermoscopy into our mole check-ups precisely because it improves our ability to decide which lesions to monitor, which to treat and which require nothing more than routine follow-up.

Risk factors in areas of high sun exposure

Ultraviolet radiation is the leading modifiable risk factor for skin cancer. The Skin Cancer Foundation estimates that around 86% of melanomas are attributed to exposure to UV radiation. This places sun protection at the heart of any skin care strategy.

In places such as Marbella and the rest of the Costa del Sol, the number of sunshine hours per year is high and outdoor living is part of everyday routine. That combination increases the cumulative UV dose received over a lifetime, which is what weighs most heavily on risk. The factors that add to risk include:

• Intense and repeated sun exposure, especially sunburns.
• Use of tanning beds.
• Fair skin, eyes and hair.
• Advanced age and the accumulation of sun damage over the years.

The good news is that much of this risk is avoidable. A proper sun protection routine, which we explain in our sun protection guide for the Costa del Sol, directly reduces the UV dose the skin receives and, with it, the long-term risk.

Self-examination and step-by-step mole check at home

Monthly self-examination is the way to detect changes early between appointments. Set aside a few minutes in a well-lit place with a full-length mirror and a hand mirror. Follow this order so you don't miss any area:

1. Face, neck and scalp. Check your face, ears and, using a hand mirror or a hair dryer to part your hair, your scalp.
2. Trunk and chest. Examine your chest, abdomen and sides. Women should also check underneath their breasts.
3. Arms and hands. Include your armpits, forearms, palms, backs of the hands, and the spaces between your fingers and under your nails.
4. Legs and feet. Don't forget the soles, heels and spaces between your toes — areas that are rarely checked.
5. Back and buttocks. Use the full-length mirror together with the hand mirror, or ask someone you trust to help you with the areas you cannot see.

A reference photo of each mole you are monitoring makes it easier to compare its evolution month by month. Note any new lesion, a mole that grows or changes, or one that itches, bleeds or won't heal. With that information, your professional check-up will be faster and more accurate.

Self-examination detects warning signs; diagnosis is the specialist's responsibility. If you have identified a mole that meets any of the ABCDE rule criteria or that has changed, book a mole check with dermoscopy at Clínica Valorian. An early assessment is the simplest and most effective decision you can make today for the health of your skin.