Six-Year Outcome of Lentigo Maligna Treated with "Spaghetti" Technique and Margin Identification by Reflectance Confocal Microscopy

Lentigo maligna (LM) and LM melanoma (LMM) present surgical challenges due to their poorly defined boundaries, making it difficult to determine precise peripheral margins. In addition, their preferential localization on the face increases the need to minimize the amount of tissue excised. Striking a balance between reducing the excision size and maintaining oncologic effectiveness is critical in managing LM/LMM. Reflectance Confocal Microscopy (RCM), a noninvasive imaging method that provides cellular-level visualization, could be an ideal tool to define the peripheral margins in the "spaghetti" surgical technique. This study aimed to evaluate the long-term outcomes of using RCM combined with the "spaghetti" technique for LM/LMM excisions. Seventy patients with LM/LMM on the face underwent RCM-guided margin definition followed by the "spaghetti" technique. The sample of patients was the same group of patients included in the authors' 2017 study. The authors subsequently evaluated the effectiveness of the authors' protocol via regular follow-up of the cohort. A total of 59 LMs and 11 LMMs were included. The mean follow-up time was 6.3 years. The recurrence rate was 5.7%. The authors identified 4 recurrences: 3 of which occurred more than 5 years after the procedure. The recorded mortality was 20%, no deaths were attributed to LM/LMM. The mean margin from lesion to clearance was 2.7 mm. If the authors cluster the 3 principal studies in terms of cohort and follow-up time for LM/LMM treated by Wide local Excision, the recurrence rate is from 5.3% to 5.9%, which is equivalent to the authors'. However, the mean margin excision from lesion is more than 2 times inferior in the authors' protocol (2.7 mm vs 6.7 mm). Therefore, the spaghetti technique with RCM margin identification seems to be an effective method for LM/LMM management.