In recent years, there has been an ongoing interest in topical treatment for lentigo Maligna (LM) as imiquimod 5% cream owing to the localization of this tumor and the advanced age of patients; however, the efficacy of imiquimod 5% cream is controversial, and the rate of local relapses is about 25–53%. Reflectance confocal microscopy (RCM) is a non-invasive diagnostic helpful tool for diagnostic purposes and for monitoring the response to the local treatment of LM. The researchers aimed to demonstrate the role of RCM in the follow‐up of a topical treatment with imiquimod 5% cream in clinical practice. The researchers reported three patients with histopathologically confirmed LM who were not candidates for surgery and were successfully treated with imiquimod 5% cream. In such patients, dermatoscopic images and reflectance confocal microscopy helped evaluate treatment response and verify long‐term clinical benefits during the follow‐up visits.

They observed no relapses in the patients 18 months after the end of treatment; although, continuous follow‐up visits are needed. In the case series presented herein, the researchers highlight the importance of RCM as a noninvasive tool to monitor the efficacy of imiquimod to treat LM during and after treatment. Detailed confocal images of two of their patients allowed us to establish atypical cells’ persistence and continue treatment. However, clinical and dermatoscopic examinations showed “apparent complete remission” after the first cycle of therapy.

Ref: https://onlinelibrary.wiley.com/doi/10.1111/ijd.15070