A risk‐scoring model for the differential diagnosis of lentigo maligna and other atypical pigmented facial lesions of the face: The facial iDScore

Abstract

BackgroundDue to progressive ageing of the population, the incidence of facial lentigo maligna (LM) of the face is increasing. Many benign simulators of LM and LMM, known as atypical pigmented facial lesions (aPFLs—pigmented actinic keratosis, solar lentigo, seborrheic keratosis, seborrheic‐lichenoid keratosis, atypical nevus) may be found on photodamaged skin. This generates many diagnostic issues and increases the number of biopsies, with a subsequent impact on aesthetic outcome and health insurance costs.ObjectivesOur aim was to develop a risk‐scoring classifier‐based algorithm to estimate the probability of an aPFL being malignant. A second aim was to compare its diagnostic accuracy with that of dermoscopists so as to define the advantages of using the model in patient management.Materials and MethodsA total of 154 dermatologists analysed 1111 aPFLs and their management in a teledermatology setting: They performed pattern analysis, gave an intuitive clinical diagnosis and proposed lesion management options (follow‐up/reflectance confocal microscopy/biopsy). Each case was composed of a dermoscopic and/or clinical picture plus metadata (histology, age, sex, location, diameter). The risk‐scoring classifier was developed and tested on this dataset and then validated on 86 additional aPFLs.ResultsThe facial Integrated Dermoscopic Score (iDScore) model consisted of seven dermoscopic variables and three objective parameters (diameter ≥ 8 mm, age ≥ 70 years, male sex); the score ranged from 0 to 16. In the testing set, the facial iDScore‐aided diagnosis was more accurate (AUC = 0.79 [IC 95% 0.757–0.843]) than the intuitive diagnosis proposed by dermatologists (average of 43.5%). In the management study, the score model reduced the number of benign lesions sent for biopsies by 41.5% and increased the number of LM/LMM cases sent for reflectance confocal microscopy or biopsy instead of follow‐up by 66%.ConclusionsThe facial iDScore can be proposed as a feasible tool for managing patients with aPFLs.

Dermoscopy of atypical pigmented lesions of the face: Variation according to facial areas

“…[1][2][3] Then, the differential diagnosis between benign and malignant aPFLs, especially when the lesions develop on mottled chronic sun-damaged skin and/or when they display atypical appearance, can be challenging. 4,5 Indeed, some benign pigmented facial lesions may exhibit under the dermatoscope similar features to malignant lesions. From a clinico-dermoscopic point of view, these lesions are collectively referred to as atypical pigmented facial lesions (aPFLs), [4][5][6] and include lentigo maligna (LM), lentigo maligna melanoma (LMM), pigmented actinic keratosis (PAK), solar lentigo (SL), benign lichenoid keratosis (BLK), flat seborrheic keratosis (SK) and flat atypical nevi (AN).…”

“…4,5 Indeed, some benign pigmented facial lesions may exhibit under the dermatoscope similar features to malignant lesions. From a clinico-dermoscopic point of view, these lesions are collectively referred to as atypical pigmented facial lesions (aPFLs), [4][5][6] and include lentigo maligna (LM), lentigo maligna melanoma (LMM), pigmented actinic keratosis (PAK), solar lentigo (SL), benign lichenoid keratosis (BLK), flat seborrheic keratosis (SK) and flat atypical nevi (AN). Still, although the dermoscopic features of facial pigmented lesions have been widely described in the last 20 years, the current dermoscopic knowledge of pattern analysis is not accurate enough to distinguish LMM from benign/ premalignant aPFLs in equivocal cases (i.e.…”

“…iDScore facial project, https://en.idsco re.net/proje cts/facia l-lesio ns/facia l-lesio ns-2021). 3,4 Based on self-assessment, the evaluators declared different levels of experience in dermoscopy, that is, <1 year (n = 34), 1-4 years (n = 44), 5-8 years (n = 22) and >8 years (n = 54). 4 The pattern analysis relied on recognition of presence/absence of a series of 14 dermoscopic features in each dermoscopic photo.…”

“…3,4 Based on self-assessment, the evaluators declared different levels of experience in dermoscopy, that is, <1 year (n = 34), 1-4 years (n = 44), 5-8 years (n = 22) and >8 years (n = 54). 4 The pattern analysis relied on recognition of presence/absence of a series of 14 dermoscopic features in each dermoscopic photo. Based on literature consensus, the 14 dermoscopic features had been previously selected as most representative for each aPFL (Table 1).…”

“…Recently, it has been argued that the same dermoscopic features can be observed in benign aPFLs. 4,[6][7][8] Subsequently, an inverse approach, based on the identification of definitely benign dermoscopic patterns, that is, evident and regular follicular openings, keratin plugs, light brown fingerprint, diffuse opaque light brown pigmentation and comedo-like openings, was also suggested. 9 However, no study to date has investigated the distribution of these patterns according to the face area.…”