Topical Treatment of Lentigo Maligna

Lentigo maligna (LM) is a melanoma in situ on chronically sun-damaged skin, with a strong predilection to the head and neck area of the elderly. Several therapeutic options (surgery, cryotherapy, radiotherapy, imiquimod) have demonstrated efficacy in the treatment of LM. Surgical excision is the first-line therapy but can be contraindicated for comorbid patients, larger lesions and according to their location. In such cases, a topical therapy with Imiquimod 5% is a valuable alternative treatment. Its immune modifying action leads to a local anti-tumor response, which leads to a complete response in 53-100% of patients. Recurrence of LM can be observed in 15-20% of patients. The treatment of LM with Imiquimod is off-label. A few case reports and small case series exist for other topic treatment modalities such as ingenol mebutate, 5-fluorouracil and topical retinoids. To date, sufficient data which would support their use are lacking. A close follow-up of patients suffering from LM which were sucessfully treated with topical treatment modalities is essential to detect recurrence early.