Lentigo Maligna on a Difficult Location of the Face Treated with 5% Imiquimod: A Case Report of 2-Year Follow-Up

Topical imiquimod is an off-label alternative treatment for lentigo maligna used when surgery cannot be performed. Severe inflammatory response induced by this drug may generate many complaints and force patients to discontinue use. We present a case in which interval treatment with 5% topical imiquimod was implemented for severe inflammatory response. An 82-year-old Caucasian woman presented with a large, irregularly pigmented lesion on her left cheek within the scar of a previously excised melanocytic lesion diagnosed as junctional nevus. Based on dermatoscopical examination confirmed by histopathological description, lentigo maligna was diagnosed. Since the lesion was large and covered the lower left eyelid and due to the risk of disfigurement, the patient refused surgical excision. Therefore, treatment with imiquimod 5% once daily, five times per week, was offered. After 5 weeks, the treatment was stopped because of intense inflammatory reaction and ulceration. On the follow-up visit after 3 months, videodermatoscopical examination revealed changes in the pigmentation of the lentigo maligna including the presence of residual gray dots and fading of the previous dark brown and black colors. The inflammatory response had almost resolved. The second course of treatment with imiquimod five times a week was implemented again for 5 weeks, and after a 2-month interval the third course with the same regimen was started. Total clearance of the lesion was achieved, which was confirmed by videodermatoscopical examination. During the 2-year follow-up, no relapse was observed based on dermatoscopical examination. We propose interval treatment with topical imiquimod 5% lentigo maligna for severe inflammatory reactions in patients with contraindications to surgery. This could help patients overcome this typical response effect and decrease their cessation of treatment.