Imiquimod in the treatment of lentigo maligna

BACKGROUND: Lentigo maligna (LM) is treated to prevent progression to lentigo maligna melanoma (LMM). Surgery remains the treatment of choice, although topical immunotherapy with imiquimod has recently become a popular alternative. OBJECTIVES: In this review, we have analysed the published literature relating to the use of imiquimod for LM, in order to understand better the utility of this treatment. METHODS: All English language studies relating to the use of imiquimod for LM were analysed up to January 2006. RESULTS: Eleven case reports and four open-label studies were identified, comprising a total of 67 patients who completed treatment with imiquimod for LM. There was significant variability in treatment schedules and regimens. Eight patients failed to respond, with LMM developing in two of these. In certain cases there were discrepancies between clinical and histological response with some patients clearing clinically but not histologically, and vice versa. Follow-up periods were short, exceeding 12 months in only five cases. CONCLUSIONS: Although imiquimod clearly has an effect on LM, this analysis of available studies has helped to identify concerns about its use. Without controlled evidence and prolonged follow up, the use of imiquimod for LM must still be considered experimental.