Malignant melanoma

Malignant melanoma arises from the malignant transformation of melanocytes in a pigmented skin area (eg skin, mucous membranes or central nervous system) (Nambudiri, 2023). The condition can affect all ages; in recent years there has been a dramatic rise in cases in all age groups, but a particularly large increase has been seen in those aged 60 years and older (Conforti and Zalaudek, 2021). There has also been an upsurge in the number of cases among younger, white-skinned individuals (Conforti and Zalaudek, 2021).

Malignant melanoma affects both men and women and is now the fifth most common skin cancer type in the UK (Cancer Research UK, 2019). The incidence of this cancer type has more than doubled in women and tripled in men since the early 1990s (Memon et al, 2021). As well as older age, other risk factors include (Zehtab, 2024):

• History of any skin cancer type
• Family history

There are several forms of melanoma (Table 1), and the appearance of the condition varies according to the type and site of the lesion.

Melanocytes produce melanin, which is a protein found in all skin types. Its role is to protect the skin from potential harm through exposure to ultraviolet radiation. Dark skin tones produce more melanin than light skin, so the latter is more vulnerable to damage from excess ultraviolet exposure.

Cancerous change occurs when melanocytic skin cells undergo a genetic transformation, causing uncontrolled proliferation (Zehtab, 2024). Melanoma develops as a result of the grouping of multiple abnormalities in the melanocyte genetic pathways, which initiate cell proliferation and cessation of apoptosis (a process that eliminates unwanted or damaged cells) (Sample and He, 2018). Mutations in several genes are thought to play a part, with alterations to the NRAS gene being affected in 15–20% of cases, and a mutation in the BRAF gene accounting for approximately 50% of cases (Strashilov and Yordanov, 2021). BRAF kinase regulates the signalling pathway that controls cell division and

Any patient presenting with a suspicious lesion should be referred urgently on a suspected cancer pathway (for an appointment within a 2-week wait), where diagnosis is confirmed in secondary care following biopsy results (National Institute for Health and Care Excellence, 2023). When assessing patients, the weighted seven-point checklist shown below may be helpful, where a score of three or more suggests urgent referral is needed (National Institute for Health and Care Excellence, 2023).

Major features of the lesion (two points for each):

• Change in shape
• Irregular shape
• Irregular colour

Minor features of the lesion (one point for each):

• Largest diameter 7 mm or more
• Inflammation
• Oozing
• Change in sensation

Another useful assessment tool is the ABCDE (Abassi et al, 2004):  

A: Asymmetry

B: Irregular borders

C: Multiple colours

D: Diameter >6 mm 

E: Evolving (with respect to size, shape, shades of colour, surface or symptoms)

Biopsy is the definitive

Treatment will depend on the stage of the melanoma at diagnosis and the degree of spread, as well as the patient’s health status and age. Patients are treated in secondary care under the guidance of a specialist multidisciplinary team, comprising doctors, nurses and other allied health professionals who have relevant knowledge and experience in this cancer type. Treatment options are as follows (National Institute for Health and Care Excellence, 2022):