Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2025;15(2):5425 1 Long-Term Response to Imiquimod for the Treatment of Lentigo Maligna Assessed With Digital Dermoscopy Luisina Caliani1, Gabriel Salerni1, 2 1 Dermatology Department, Hospital Provincial del Centenario de Rosario, Universidad Nacional de Rosario, Rosario, Argentina 2 Grupo Centro, Rosario, Argentina Citation: Caliani L, Salerni G. Long-Term Response to Imiquimod for the Treatment of Lentigo Maligna Assessed With Digital Dermoscopy. Dermatol Pract Concept. 2025;15(2):5425. DOI: https://doi.org/10.5826/dpc.1502a5425 Accepted: February 27, 2025; Published: April 2025 Copyright: ©2025 Caliani et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Gabriel Salerni, Dermatology Department, Hospital Provincial del Centenario de Rosario, Universidad Nacional de Rosario, Rosario, Argentina; Grupo Centro, Rosario, Argentina. ORCID ID: 0000-0001-6386-4402. E-mail: gabrielsalerni@hotmail.com Case Presentation A 72-year-old woman presented with 4 cm irregular pig- mented lesion on the right cheek with a histological diag- nosis of lentigo maligna (LM). Given the size and location of the lesion, the patient was treated with imiquimod 5% cream applied 5 days per week, once daily. The treatment induced a moderate local inflammatory reaction, includ- ing erythema and crusting, and was discontinued after six weeks. Two months after the end of therapy, dermoscopy revealed disappearance of LM-specific patterns. Follow-up evaluations with digital dermoscopy using polarized light (Fotofinder Systems GmBH, Bad Birnbach, Germany) were scheduled every 6 months. The lesion was mapped in a standardized manner for adequate comparison; no evidence of recurrence was observed after 30 months of follow-up (Figure-1). Teaching Point Lentigo maligna (LM) is a form of melanoma in situ com- monly found on sun-exposed skin, particularly in older adults. Although surgical excision is the standard treatment, non-surgical approaches such as imiquimod offer a less in- vasive option, especially for extensive lesions in cosmetically sensitive areas [1,2]. Imiquimod, an immunological response modifier, stimulates both innate and adaptative immunity to eliminate atypical cells. Although it represents an effective alternative to surgery, careful patient selection and long-term follow-up are crucial. There is no consensus about follow-up recommendations for monitoring medical treatment of LM. Reflectance confocal microscopy (RCM) reveals additional information to dermoscopy, and it has been proposed as a useful tool for monitoring response. Since RCM is not widely available, sequential dermoscopy follow-up in search of early signs of recurrence remains as a very useful tool. 2 Image Letter | Dermatol Pract Concept. 2025;15(2):5425 References 1. Tio DCKS, van Montfrans C, Ruijter CGH, Hoekzema R, Bekkenk MW. Effectiveness of 5% Topical Imiquimod for Lentigo Maligna Treatment. Acta Derm Venereol. 2019 Sep 1;99(10): 884-888.  DOI: 10.2340/00015555-3241. Figure 1. (A) Lentigo maligna in the right cheek before treatment in March 2022; (B) after nine months of discontinuing treatment, in May 2023, and (C) 30 months after treatment, in November 2024. 2. Poveda-Montoyo I, Álvarez-Chinchilla P, Schneller-Pavelescu L, Hispán-Ocete P, Bañuls-Roca J. Series of Fourteen Cases of Top- ical Imiquimod 5% in Lentigo Maligna: Treatment Modalities and Clues for Detecting Recurrences. Actas Dermosifiliogr. 2022;113(4):407-412. DOI:10.1016/j.ad.2021.07.018. PMID: 35431054.