Melanoma: spotting a dangerous mole, diagnosis and treatment

What melanoma is

Melanoma is a cancer of melanocytes, the cells that make the pigment melanin and give skin its colour. It can arise from an existing mole but more often appears as a new spot on normal skin. Less commonly, melanoma develops on mucous membranes, under the nails, in the eye, or on the soles and palms.

The main types are superficial spreading melanoma (the most common), nodular melanoma (which grows quickly in depth), lentigo maligna melanoma (on sun-damaged facial skin in older people) and acral lentiginous melanoma (on the palms, soles and under the nails).

Risk factors

• Ultraviolet radiation – blistering sunburn, especially in childhood, and sunbed use. Sunbeds are classified by the International Agency for Research on Cancer as carcinogenic to humans.
• Fair skin, light or red hair, freckles and a tendency to burn.
• Many moles (more than 50) or atypical (dysplastic) moles.
• Family history of melanoma in a close relative.
• Previous melanoma or other skin cancer.
• A weakened immune system, for example after organ transplantation while taking immunosuppressive medicines.

Sun protection – shade at midday, clothing, a hat, sunglasses and high-factor sunscreen – is central to cancer prevention for the skin.

Melanoma signs: the ABCDE rule

Dermatologists use the easy-to-remember ABCDE checklist:

• A – Asymmetry: the two halves of the spot do not match.
• B – Border: irregular, notched or blurred edges.
• C – Colour: several shades, such as brown, black, red, blue or grey.
• D – Diameter: usually more than 6 mm, although melanoma can be smaller.
• E – Evolving: changes in size, shape or colour, becoming raised, itching or bleeding.

The "ugly duckling" sign is also useful: a mole that looks different from all the others on your body. Nodular melanoma often does not fit the ABCDE pattern; it is raised, firm and grows within weeks. Any rapidly growing, bleeding or non-healing spot should be checked.

Diagnosis: dermoscopy, biopsy and staging

A dermatologist examines the skin with a dermatoscope, a magnifying device with special lighting that greatly improves accuracy. People with many moles may also have digital mole mapping to compare changes over time.

If melanoma is suspected, the whole lesion is removed with a narrow margin (excision biopsy) and examined under the microscope. The pathologist reports:

• Breslow thickness in millimetres – the most important prognostic factor;
• whether there is ulceration;
• the rate of cell division and other features.

For melanomas thicker than about 0.8 mm or with ulceration, a sentinel lymph node biopsy is usually offered, removing the first node that drains the tumour. More advanced disease is staged with CT, brain MRI or PET-CT. The tumour is also tested for a BRAF mutation, which influences treatment choice.

Melanoma stages

Stage is set using the TNM system, based on tumour thickness and ulceration, lymph node involvement and distant spread. In simplified form:

Decisions are always individual and made by a tumour board, taking into account general health and the patient's own preferences.

Melanoma treatment

Surgery. Once melanoma is confirmed, the area is re-excised with a wider margin of healthy skin, usually 0.5 to 2 cm depending on tumour thickness. When lymph nodes are involved, the approach is more conservative than in the past: ultrasound surveillance or systemic treatment is often preferred to removing all the nodes.

Adjuvant treatment. For stage III melanoma and some high-risk stage II tumours, a year of immunotherapy with a PD-1 inhibitor may be offered after surgery or, for BRAF-mutated melanoma, targeted therapy combining BRAF and MEK inhibitors. The aim is to lower the risk of recurrence. Some patients now receive immunotherapy before surgery as well.

Advanced melanoma. Checkpoint inhibitors (alone or combined) and targeted drugs have turned metastatic melanoma from a disease with a very poor outlook into one where some patients live for many years. Radiotherapy, including stereotactic treatment for brain metastases, and cell therapies in specialist centres are also used. Immunotherapy side effects can affect the bowel, liver, skin and hormone glands and need careful monitoring. For general principles, see our guide to cancer treatment.

Follow-up and self-examination

After melanoma treatment, regular checks of the skin and lymph nodes follow, with scans for higher-stage disease, more often in the first few years. People who have had melanoma are more likely to develop a new one, so sun protection and monthly self-examination are especially important. Check your whole body in good light, including the scalp, back (with a mirror or a partner's help), soles, between the toes and under the nails.

When to see a doctor

See a dermatologist, or your GP for a referral, if:

• you notice a new mole after the age of 30, or one that looks different from the rest;
• an existing mole changes size, shape or colour, itches, bleeds or becomes crusty or ulcerated;
• a dark streak appears under a nail without any injury;
• you feel a swollen lymph node near the site of a previously removed mole.

Do not have suspicious moles removed cosmetically (by laser or burning) without a tissue diagnosis. If you have been diagnosed and systemic treatment is being discussed, a second opinion at a centre experienced in melanoma can be helpful.

Melanoma treatment abroad and in Türkiye

Many patients from Bulgaria and across Europe turn to large accredited hospital groups in Istanbul, which offer dermato-oncology, sentinel lymph node biopsy, BRAF testing and access to modern immunotherapy and targeted therapy. Check that your case is reviewed by a multidisciplinary tumour board, ask for a written plan, and agree how infusions, side-effect management and follow-up will continue at home. New City Clinic in Istanbul is a health-tourism organiser that coordinates the hospital, doctor, hotel, transfers and interpreter; medical decisions remain with the treating team.