A 46-year-old woman presents to her GP with concern about a changing mole on her upper back. She first noticed the lesion two years ago, but over the past 4 months, it has become darker, increased in size, and occasionally itches. She has a fair complexion, a history of frequent sunburns during childhood, and has used sunbeds intermittently in her 20s. She has no personal or family history of skin cancer.