Relevance of Imiquimod as Neo-adjuvant Treatment to Reduce Excision Size and the Risk of Intralesional Excision in Lentigo Malignant of the Face

Inclusion Criteria: * Patients from both sexes aged over 18 years and operable * Presenting with LM of the face, the neck, or the scalp (in case of hairless scalp only) histologically confirmed by biopsy * Patients presenting with a primitive lesion, of a surface ≥ to 1cm² and ≤ to 20cm², with the possibility of graft or flap reconstruction * LM previously untreated by surgery * LM without prior treatment with liquid nitrogen or any other local treatment within 3 months * ECOG ≤ 2 * Leucocytes ≥ 3,000/mm³ * Neutrophil count ≥ 1,500/mm³ * Platelet count ≥ 100,000/mm³ * Haemoglobin ≥ 9.0g/dL * Absence of severe evolutive infection * Absence of known HIV infection * Absence of corticotherapy and treatment by immunosuppressive agents * Absence of excoriation and scarring biopsy prior to application of study treatment * Membership to a social security insurance scheme. * Negative pregnancy test conducted during the inclusion consultation for non-menopausal women. * Effective contraception for patients of childbearing age * Signed informed consent Exclusion Criteria: * LM located on the eyelids are excluded, together with LM in anatomic sites other than the face, the neck or the scalp * Melanomas other than LM * Invasive LM * LM with a surface area \< to 1cm² or \> to 20cm² * LM of which the macroscopic contours cannot be defined * Patients who are allergic to imiquimod excipient (eg hydroxybenzoate) * Patients with a hypersensitivity to active substances or to any of the excipients of the placebo (for example propyl parahydroxybenzoate) * Patients treated by immunosuppressive agents, immunomodulators, cytotoxic agents or corticosteroids (local and systemic) during the 4-week period prior to the selection visit * Patients with auto-immune disease (except vitiligo) or transplant patients * Cutaneous reconstruction not possible * Presence of associated evolutive neoplasia since less than 5 years (with the exception of basal cell carcinoma, Bowen's carcinoma and carcinoma in situ of the cervix) * Patient refusing surgery under local or general anaesthesia * Pregnant women