Treatment of Lentigo Maligna (LM) is challenging because of the potential functional and esthetic surgical sequelae. Imiquimod has been proposed as an alternative treatment for LM. Reflectance Confocal Microscopy (RCM) is a non-invasive tool used for the diagnosis of LM and margin assessment.To compare the overall LM score assessed by RCM before and after one month of imiquimod compared to placebo and to define the immunohistochemical (IHC) profile of responders to imiquimod.A controlled randomized study was conducted. Patients underwent a RCM examination with calculation of the LM score at baseline and after 1 month of treatment. An IHC analysis of excised tissues was performed.Forty patients were included. The 1-month LM score was significantly lower in patients treated with imiquimod compared to those treated with placebo (p <0.001). The significantly different criteria were: non-edged papillae, large round pagetoid cells, atypical cells at the dermoepidermal junction, follicular location of atypical cells. The IHC analysis showed a higher level of Interferon gamma in the resected specimens of patients responding to imiquimod (p = 0.04).The sample size was small.Assessing the LM score by RCM was useful to monitor accurately LM response to imiquimod.
Anouk Soenen Resident, Morgane Vourc'h, Amir Khammari, Jean-Michel Nguyen, Céline Bossard, Marie Denis Musquer, Béatrice Vergier, Brigitte Dréno