Lentigo maligna (LM) and lentigo maligna melanoma (LMM) are melanoma subtypes associated with chronic photoexposure, often located on areas such as the face and neck. Early diagnosis of these lesions is challenging due to their similarity to other benign conditions. Non-invasive methods, such as visual inspection, dermoscopy (DMT), and reflectance confocal microscopy (RCM), have been employed to improve diagnostic accuracy and surgical margin definition. However, evidence on which technique is superior remains uncertain. This systematic review aimed to investigate whether DMT is more effective than other non-invasive methods, such as RCM and visual inspection, for the diagnosis of LM and LMM confirmed by histopathology. The literature research was conducted in PubMed, CINAHL, MEDLINE, and EMBASE databases without language and date of publication restrictions. Two independent dermatologists assessed the eligibility of the studies, extracted data, and performed a methodological quality and risk of bias analysis of the included studies (QUADAS-2). From 532 retrieved studies, 11 were included in the final analysis. The included studies showed substantial heterogeneity in design, thresholds, outcomes, and reporting, which precluded quantitative analysis. Compared with histopathology, the diagnostic performance of non-invasive methods, such as visual inspection, DMT, and RCM, was inconclusive due to several limitations. For instance, we found strong evidence of selection biases, non-consecutive sampling, lack of randomization, unblinded evaluators, and under-reporting of sensitivity and specificity. Overall, current evidence does not support replacing histopathology for confirming LM and LMM diagnosis. Standardized study protocols and reporting in the field of non-invasive diagnosis of LM and LMM are needed.
Gallo et al. (Sun,) studied this question.