Background The surgical treatment of lentigo maligna melanoma is associated with high rates of local recurrence. Handheld reflectance confocal microscopy (HH‐RCM) allows for in vivo presurgical detection of subclinical lentigo maligna (melanoma) (LM/LMM). Methods A single‐center retrospective study from December 2015 to July 2017. Frequency and extent of negative surgical margins, and the diagnostic accuracy of presurgical mapping by HH‐RCM was determined. Results Twenty‐six consecutive patients with LM/LMM were included. In 45.8%, HH‐RCM detected subclinical LM with a sensitivity of 0.90 and specificity of 0.86. The management was changed in two (7.7%) patients. Of the 24 remaining lesions, 95.8% were excised with negative margins with a mean histological margin of 3.1 and 5.3 mm for LM and LMM, respectively. At a mean follow‐up of 36.7 months, there was one (4.8%) confirmed recurrence. Conclusions Our method of presurgical delineation by HH‐RCM appears to provide a reliable method for the surgical treatment of LM/LMM with a limited rate of overtreatment.

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Because of an increased risk of local recurrence following surgical treatment of lentigo maligna (melanoma) (LM/LMM), the optimal surgical technique is still a matter of debate. We aimed to evaluate the effect of different surgical techniques and reflectance confocal microscopy (RCM) on local recurrence and survival outcomes. We searched MEDLINE, Embase and PubMed databases through 20 May 2022. Randomized and observational studies with ≥10 lesions were eligible for inclusion. Bias assessment was performed using the Methodological Index for Non‐Randomized Studies instrument. Meta‐analysis was performed for local recurrence, as there were insufficient events for the other clinical outcomes. We included 41 studies with 5059 LM and 1271 LMM. Surgical techniques included wide local excision (WLE) (n = 1355), staged excision (n = 2442) and Mohs' micrographic surgery (MMS) (n = 2909). Six studies included RCM. The guideline‐recommended margin was insufficient in 21.6%–44.6% of LM/LMM. Local recurrence rate was lowest for patients treated by MMS combined with immunohistochemistry (<1%; 95% CI, 0.3%–1.9%), and highest for WLE (13%; 95% CI, 7.2%–21.6%). The mean follow‐up varied from 27 to 63 months depending on surgical technique with moderate to high heterogeneity for MMS and WLE. Handheld‐RCM decreased both the rate of positive histological margins (p < 0.0001) and necessary surgical stages (p < 0.0001). The majority of regional (17/25) and distant (34/43) recurrences occurred in patients treated by WLE. Melanoma‐associated mortality was low (1.5%; 32/2107), and more patients died due to unrelated causes (6.7%; 107/1608). This systematic review shows a clear reduction in local recurrences using microscopically controlled surgical techniques over WLE. The use of HH‐RCM showed a trend in the reduction in incomplete resections and local recurrences even when used with WLE. Due to selection bias, heterogeneity, low prevalence of stage III/IV disease and limited survival data, it was not possible to determine the effect of the different surgical techniques on survival outcomes.