Effect of Topical Imiquimod on Lentigo Maligna

Inclusion Criteria: * Clinical diagnosis of lentigo maligna (LM) (acquired pigmented macule present for more than 12 months with no change in skin surface texture or contour, no palpability, diameter \>10 mm, sited on the head or neck). The lower anatomical limit is the root of the neck - a line joining the medial end of the clavicles with the medial insertion of trapezius. * Histological findings consistent with LM (increased numbers of atypical melanocytes confined to the epidermis, sun damaged skin) in one or more 4mm punch biopsies(s) from the darkest area, reported by a pathologist with expertise in the diagnosis of melanocytic lesions, and part of a recognised NHS skin cancer Multi-Disciplinary Team. * The upper limit of the lesion is not defined by size, but it must be suitable for complete surgical excision using a 5 mm lateral margin. * The outline of the lesion must be easily defined visually in daylight around its entire circumference. * Patient fit enough and willing to undergo surgery as required by the protocol. Exclusion Criteria: * Clinical or histological evidence of invasive melanoma including any palpability of the lesion, or clinical and/or histological evidence of regression or dermal invasion * Aged less than 45 years * Recurrent LM - the index lesion must not have been previously treated * Life expectancy of less than 12 months * Other skin lesions which may compromise the ability to complete this study, such as co-existing or adjacent melanoma or non-melanoma skin cancer. Co-existing adjacent actinic keratoses would not exclude the patient from the study * Women of childbearing potential, who are pregnant, plan to become pregnant during their study participation or breastfeeding. * Unable to give informed consent. * Hypersensitivity to imiquimod or to any of the excipients (methylhydroxybenzoate (E218), propylhydroxybenzoate (E216), cetyl alcohol and stearyl alcohol). * Taking immunosuppressive medication. * Taking part in any other intervention study.