Skin cancer

Types of skin cancer

The main types of skin cancer are:

• Actinic keratoses: appear as rough, pink or scaly spots, usually on the face, scalp, neckline or hands. They are precancerous lesions that must be treated because they can progress to squamous cell carcinoma.
• Keratinocyte carcinomas: squamous cell carcinoma appears as a rapidly growing lump, tumour or wart on sun-exposed areas. It may spread to other organs if left untreated. Basal cell carcinoma grows more slowly and is less aggressive; it appears as a patch or lump with pearly, shiny edges that may ulcerate or bleed.
• Melanoma: presents as a dark brown or black spot, a “new mole” or a change in a pre-existing mole. It is less common but more aggressive than the previous types.
• Other less common cancers include dermatofibrosarcoma protuberans, Merkel cell carcinoma, Kaposi sarcoma and cutaneous lymphomas.

The role of the dermatologist

The dermatologist is the specialist responsible for the diagnosis, treatment and follow-up of skin cancer. Their role is essential to:

• Distinguish benign from malignant lesions.
• Choose the most appropriate treatment according to the type of tumour.
• Coordinate with other specialists in more complex cases.

Types of treatment

Treatment depends on the type of skin cancer and how far it has spread:

• Actinic keratoses: topical treatments (creams), cryotherapy (cold applied in the clinic) or photodynamic therapy.
• Basal and squamous cell carcinomas: dermatologic surgery, topical or intralesional treatments, or radiotherapy in selected cases. More advanced cases may require systemic treatments administered orally or intravenously.
• Mohs surgery: a specialised technique that removes the tumour while immediately checking the margins under a microscope, preserving as much healthy skin as possible. It is used for high-risk tumours on the face or other delicate areas, where precision and aesthetic outcome are essential.
• Melanoma: surgery to remove the skin tumour, in one or two stages, and sentinel lymph node biopsy (in selected cases). High-risk or advanced cases may also require more complex surgeries or systemic oncology treatments (immunotherapy, targeted therapies).
• Other rare tumours: surgical and/or systemic treatments depending on the type.

In the most serious or complex cases, treatment decisions are made by the Cutaneous Tumour Committee, which includes dermatologists, oncologists, pathologists, surgeons and other specialists.

The skin cancer consultation: what to expect

If you are referred to the specialised skin cancer consultation, you should know that:

• The dermatologist will ask you to undress for a full skin examination, with the naked eye and with a dermatoscope, and will palpate lymph node areas (neck, armpits and groin).
• A skin biopsy may be required, which involves taking a small sample of skin under local anaesthesia, always with your consent.
• Clinical photographs are often taken to document the lesion, monitor its evolution and, in some cases, for teaching or research purposes.
• If you meet certain criteria, you may be referred to a digital image registry consultation (Fotofinder) for specialised follow-up.
• Sometimes a skin ultrasound is performed during the consultation, or imaging tests are requested from Radiology (CT, MRI, PET, etc.).

Once the diagnosis is confirmed, the most appropriate treatment will be explained and follow-up will be planned.

Transplant patients

People who have received a solid organ transplant and take immunosuppressive medication have a much higher risk of developing skin cancer than the general population, and this risk increases with the years after the transplant. Although all skin tumours are more frequent in this group, squamous cell carcinoma is the most common type.

The importance of self-examination

Early detection saves lives. Transplant patients should check their entire skin at least once every 3 months, in a well-lit room and with the help of a mirror or a family member.

You should examine:

• Face, lips and ears (including behind the ears).
• Scalp, especially in bald areas.
• Neck, chest, abdomen, back and buttocks.
• Arms, hands, nails and armpits.
• Legs, feet, soles and spaces between the toes.
• Genitals and oral mucosa.

Signs to suspect skin cancer

Request an urgent appointment with a dermatologist if you notice:

• A wound or scab that does not heal within a month.
• A lesion that bleeds spontaneously or becomes ulcerated.
• A rapidly growing lump.
• A rough or scaly patch on the head, hands or another sun-exposed area.
• A new dark spot or a mole that changes shape, size or colour (ABCDE rule of melanoma: Asymmetry, Border irregularity, Colour variation, Diameter >6 mm, Evolution over time).

Prevention of skin cancer

Prevention is essential and within everyone’s reach:

• Avoid sun exposure during the middle hours of the day (11 am–4 pm).
• Wear protective clothing: wide-brimmed hat, sunglasses, long-sleeved shirts, long trousers or skirts.
• Apply broad-spectrum sunscreen (UVA and UVB) every day: SPF ≥30 for the general population, SPF ≥50 for transplant patients if exposed to the sun. Reapply every 2 hours and after swimming.
• Do not use tanning booths.
• Check your skin regularly and see a dermatologist if you notice any suspicious lesion.

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