Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis

European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and Venereology and Union of Medical Specialists (Union Européenne des Médecins Spécialistes)

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

Melanoma clinicopathological groups characterized and compared with dermoscopy and reflectance confocal microscopy

BACKGROUND

Dermoscopic and reflectance confocal microscopy (RCM) correlations between morphologic groups of melanoma have not yet been described.

OBJECTIVE

Describe and compare dermoscopic and RCM features of cutaneous melanomas with histopathological confirmation.

METHODS

Single center, retrospective analysis of consecutive melanomas evaluated with RCM (2015-2019). Lesions were clinically classified as typical, nevus-like, amelanotic/nonmelanoma skin cancer (NMSC)-like, seborrheic keratosis (SK)-like and lentigo/lentigo maligna (LM)-like. Presence or absence of common facial and nonfacial melanoma dermoscopic and RCM patterns were recorded. Clusters were compared with typical lesions by multivariate logistic regression.

RESULTS

Among 583 melanoma lesions, significant differences between clusters were evident (compared to typical lesions). Observation of dermoscopic features (>50% of lesions) in amelanotic/NMSC-like lesions consistently displayed 3 patterns (atypical network, atypical vascular pattern + regression structures), and nevus-like and SK-like lesions and lentigo/LM-like lesions consistently displayed 2 patterns (atypical network + regression structures, and nonevident follicles + heavy pigmentation intensity). Differences were less evident with RCM, as almost all lesions were consistent with melanoma diagnosis.

LIMITATIONS

Small SK-like lesions sample, single RCM analyses (no reproduction of outcome).

CONCLUSION

RCM has the potential to augment our ability to consistently and accurately diagnose melanoma independently of clinical and dermoscopic features.

Lentigo maligna and lentigo maligna melanoma in vivo differentiation with dermoscopy and reflectance confocal microscopy: A retrospective, multicentre study

INTRODUCTION

Dermoscopic predictors of lentigo maligna (LM) and lentigo maligna melanoma (LMM) have been recently reported, but these have not been reported in reflectance confocal microscopy (RCM).

OBJECTIVES

(i) To validate dermoscopic predictors for LM/LMM, (ii) to identify RCM patterns in LM and LMM, and (iii) correlations between dermoscopic and RCM features in LM and LMM.

MATERIALS AND METHODS

A retrospective, multicentre study of consecutive lesions with histologically proven LM or LMM subtypes of the head and face, with complete sets of dermoscopic and RCM images.

RESULTS

A total of 180 lesions were included (n = 40 LMM). Previously reported differential dermoscopic features for LM subtypes were confirmed. Other features significantly associated with LMM diagnosis included irregular hyperpigmented areas, shiny white streaks, atypical vessels and light brown colour at dermoscopy and medusa head-like structures, dermal nests and nucleated cells within the papillae at RCM (p < 0.05). Correlations among LM lesions between dermoscopic and RCM features included brown to-grey dots and atypical cells (epidermis), grey colour and inflammation and obliterated follicles and medusa head-like structures. Among LMM lesions, significant correlations included obliterated follicles with folliculotropism, both irregular hyperpigmented areas and irregular blotches with widespread atypical cell distribution (epidermis), dermal nests and nucleated cells within the papillae (dermis). Irregular blotches were also associated with medusa head-like structures (dermal epidermal junction [DEJ]).

CONCLUSIONS

Dermoscopic and RCM features can assist in the in vivo identification of LM and LMM and many are correlated. RCM three-dimensional analysis of skin layers allows the identification of invasive components in the DEJ and dermis.

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

BACKGROUND

Due 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.

OBJECTIVES

Our 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 METHODS

A 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.

RESULTS

The 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%.

CONCLUSIONS

The facial iDScore can be proposed as a feasible tool for managing patients with aPFLs.

Photodynamic Therapy is an Effective Treatment of Facial Pigmented Actinic Keratosis

BACKGROUND

Actinic keratosis (AK), or solar keratosis, is a precancerous condition of the skin, mainly caused by excessive and chronic exposure to ultraviolet radiation. Pigmented AK (pAK) is a rare variant of AK. Photodynamic therapy (PDT) is widely used to treat the classical variant of AK, but very limited data are available on the use of PDT in patients with pAK. The objective of this study was to assess the usefulness of PDT in the treatment of pAK.

METHODS

The study included 16 patients with 20 pAK lesions treated with PDT. All skin lesions were clinically and dermatoscopically assessed for typical features characteristic of pAK. Reflectance confocal microscopy (RCM) was also used to assess keratinocyte atypia, confirm pAK diagnosis, and rule out other disease entities.

RESULTS

After three PDT sessions, the complete resolution of all clinical features of pAK was observed in 80% of the studied lesions. Dermatoscopically, 65% of the lesions achieved 100% response and no cellular atypia was seen in the follow-up RCM images of 85% of lesions.

CONCLUSIONS

Photodynamic therapy is an effective treatment modality for pAK in fair-skinned individuals.

Observational study investigating the level of support from a convolutional neural network in face and scalp lesions deemed diagnostically 'unclear' by dermatologists

BACKGROUND

The clinical diagnosis of face and scalp lesions (FSL) is challenging due to overlapping features. Dermatologists encountering diagnostically 'unclear' lesions may benefit from artificial intelligence support via convolutional neural networks (CNN).

METHODS

In a web-based classification task, dermatologists (n = 64) diagnosed a convenience sample of 100 FSL as 'benign', 'malignant', or 'unclear' and indicated their management decisions ('no action', 'follow-up', 'treatment/excision'). A market-approved CNN (Moleanalyzer-Pro®, FotoFinder Systems, Germany) was applied for binary classifications (benign/malignant) of dermoscopic images.

RESULTS

After reviewing one dermoscopic image per case, dermatologists labelled 562 of 6400 diagnoses (8.8%) as 'unclear' and mostly managed these by follow-up examinations (57.3%, n = 322) or excisions (42.5%, n = 239). Management was incorrect in 58.8% of 291 truly malignant cases (171 'follow-up' or 'no action') and 43.9% of 271 truly benign cases (119 'excision'). Accepting CNN classifications in unclear cases would have reduced false management decisions to 4.1% in truly malignant and 31.7% in truly benign lesions (both p < 0.01). After receiving full case information 239 diagnoses (3.7%) remained 'unclear' to dermatologists, now triggering more excisions (72.0%) than follow-up examinations (28.0%). These management decisions were incorrect in 32.8% of 116 truly malignant cases and 76.4% of 123 truly benign cases. Accepting CNN classifications would have reduced false management decisions to 6.9% in truly malignant lesions and to 38.2% in truly benign cases (both p < 0.01).

CONCLUSIONS

Dermatologists mostly managed diagnostically 'unclear' FSL by treatment/excision or follow-up examination. Following CNN classifications as guidance in unclear cases seems suitable to significantly reduce incorrect decisions.

Dermatoscopic finding of white circles in an invasive pigmented melanoma

Dermatoscopic white circles, seen with both non-polarized and polarized dermatoscopy, are a known clue to actinic keratosis in a flat lesion and invasive squamous cell carcinoma in a raised lesion. We have not discovered a previous published example of this clue in a melanoma. We present a case report of a 70-year-old Australian male with a pigmented superficial spreading melanoma on the face, Breslow thickness 1 mm, with dermatoscopic white circles displayed with both polarized and non-polarized dermatoscopy, and with dermatopathological correlation.

Pigmented Macules on the Head and Neck: A Systematic Review of Dermoscopy Features

INTRODUCTION

Differentiating early melanoma from other flat pigmented lesions on the head and neck is challenging both clinically and dermoscopically, partly due to the wide differential diagnosis and the lack of specific diagnostic algorithms.

OBJECTIVES

To review publications covering the dermoscopic features of pigmented macules on the head and neck.

METHODS

Embase and PubMed (Medline) database from January 2015 to January 2021 were searched using a four-step search. Keywords used were dermoscopy/dermatoscopy or epiluminescence microscopy, lentigo maligna, lentigo maligna melanoma, lichen-planus-like-keratosis, solar lentigo, seborrheic keratosis, pigmented actinic keratosis (PAK), pigmented Bowen disease (pBD), pigmented intraepidermal carcinoma (pIEC) and head and neck.

RESULTS

The commonest reported dermoscopic features of facial melanoma were irregular dots, atypical dots/globules, asymmetric pigmented follicular openings, rhomboid gray/black structures, increased vascular network, brown globules/dots and a pattern of circles. Pseudopods, radial streaming, blue white veil, irregular blotches, scar-like depigmentation and atypical pigment network were recorded in low frequencies. For PAK, pBD and pIEC perifollicular erythema, white/yellow surface scale, linear wavy vessels around hair follicles, hair follicular openings surrounded by a white halo, evident follicles or follicular or keratotic plugs, rosette sign and sharply demarcated borders were the salient features.

CONCLUSIONS

Further studies are needed to determine the dermoscopic criteria for pigmented melanocytic and non-melanocytic lesions on the head and neck. Furthermore, there is a gap in the knowledge of site-specific dermoscopic features on specific sites, namely ears, nose, cheeks, scalp and neck which will also benefit from further studies.

Frequency of Publication of Dermoscopic Images in Inter-observer Studies: A Systematic Review

Research interest in dermoscopy is increasing, but the complete dermoscopic image sets used in inter-observer studies of skin tumours are not often shared in research publications. The aim of this systematic review was to analyse what proportion of images depicting skin tumours are published in studies investigating inter-observer variations in the assessment of dermoscopic features and/or patterns. Embase, MEDLINE and Scopus databases were screened for eligible studies published from inception to 2 July 2020. For included studies the proportion of lesion images presented in the papers and/or supplements was extracted. A total of 61 studies (53 original studies and 8 shorter reports (i.e. research letters or concise reports)). published in the period 1997 to 2020 were included. These studies combined included 14,124 skin tumours, of which 373 (3%) images were published. This systematic review highlights that the vast majority of images included in dermoscopy research are not published. Data sharing should be a requirement for future studies, and must be enabled and standardized by the dermatology research community and editorial offices.

Fluorescence-advanced videodermatoscopy (FAV) for the differential diagnosis of suspicious facial lesions: A single-centre experience with pattern analysis and histopathological correlation

BACKGROUND

Fluorescence-advanced videodermatoscopy (FAV) is a new non-invasive high-resolution skin imaging technique to assess pigmented lesions in conjunction with the clinical examination and dermatoscopy.

OBJECTIVES

This is the first prospective study to identify morphologic descriptors and standardized terminology to examine facial pigmented lesions using FAV. The objectives were to identify FAV indicators, which can assist physicians in diagnosing suspicious flat facial pigmented lesions.

METHODS

Consecutive equivocal pigmented lesions were retrospective analysed. Histopathological examination was performed for all the lesions. The main cytomorphological and cytoarchitectural FAV features were described and correlated with histopathological characteristics.

RESULTS

From January to October 2020, 21 consecutive clinically suspected pigmented lesions in 20 patients were analysed using dermatoscopy and FAV and then surgically excised. Histopathological examination identified lentigo maligna (LM), lentigo maligna melanoma (LMM), solar lentigo (SL), flat seborrheic keratosis (SK) and pigmented actinic keratosis (PAK). Thirteen malignant melanocytic lesions were removed (11 LM, 2 LMM), two were diagnosed as PAK, and the remaining six pigmented lesions were SL-SKs. With FAV, large ovoid pleomorphic and dendritic cells arranged in the intrafollicular disposition, are typical of most malignant melanocytic lesions (12/13, 92.3%). No benign lesions displayed these features. In dermatoscopy, this folliculotropism corresponded to the presence of an annular-granular pattern with slate grey dots that were aggregated asymmetrically around follicular openings.

CONCLUSIONS

FAV features can provide an improved diagnostic approach in the differential diagnosis of flat pigmented facial lesions.

Confocal microscopy, dermoscopy, and histopathology features of atypical intraepidermal melanocytic proliferations associated with evolution to melanoma in situ

BACKGROUND

Atypical intraepidermal melanocytic proliferations (AIMP) is a descriptive term sometimes applied to biopsies that do not fulfill diagnostic criteria of melanoma. They are common on sun-damaged skin, but their definition and management are controversial.

OBJECTIVE

To describe dermoscopic (DS), reflectance confocal microscopic (RCM) and histopathological features of AIMP and identify features associated with subsequent melanoma in situ (MIS).

METHODS

A retrospective analysis of AIMP lesions correlated with patient outcome at two melanoma tertiary centers between 2005 and 2015.

RESULTS

Thirty-four patients were included. Nine (26%) patients had MIS in subsequent biopsies. Predictors of later MIS were target-like pattern (OR:12.0 [CI: 1.23, 117.41]; P = 0.032) and high-density vascular network (OR:12 [CI: 1.23-117.41], P: 0.032) on DS, and presence of dendritic cells touching each other (OR:9.1 [CI: 1.54, 54.59], P = 0.014) on RCM. Clinical predictors of worse outcome included a previous history of MIS at the same site. Radiotherapy for AIMP had a high failure rate (all patients presented with recurrent disease, three as AIMP and two as MIS).

CONCLUSIONS

Considering that most cases in this series received non-surgical treatment at baseline, we recommend close monitoring for lesions with target-like pattern and density vascular network on DS and treatment for lesions with progression of atypia and/or with "confluent" dendritic cells on RCM. Although the number of patients in this series is very low, early surgery is recommended for MIS cases that recur as AIMP.

Dermatoscopic findings and dermatopathological correlates in clinical variants of actinic keratosis, Bowen's disease, keratoacanthoma, and squamous cell carcinoma

Non-melanoma skin cancer (NMSC), predominantly squamous cell carcinoma (SCC) and basal cell carcinoma, is increasing worldwide. Dermatoscopy, which is one of the non-invasive diagnostic techniques, is important for early diagnosis of NMSC. In this study we aimed to determine dermatoscopic features of keratinocyte derived tumors including actinic keratosis (AK), Bowen's disease (BD), keratoacanthoma (KA), and SCC and correlate the dermatoscopic findings with pathology. A total of 242 lesions from 169 patients were included in the study and dermatoscopic and dermatopathological findings of the lesions were retrospectively studied. Revised pattern analysis was used for the dermatoscopic evaluation. Among 242 lesions, 145 were clinically flat (86 AK, 30 BD, and 29 SCC). Presence of vessels, ulceration, fiber sign, keratin mass, and blood spots decreased the probability of a lesion being AK. When the differential diagnosis was considered between KA and SCC vs AK and BD; vessel presence, ulceration, fiber sign, blood spots, white structureless, keratin, and centred vessels favored the diagnosis of KA and SCC. Our results may contribute to the determination of the lesions to be biopsied in patients with multiple AK on chronically sun damaged skin. In non-pigmented lesions when a final diagnosis cannot be established, knowledge of dermatopathologic and dermatoscopic correlation may significantly assist interpretation of dermatoscopic patterns and clues.

Skin lesions of face and scalp - Classification by a market-approved convolutional neural network in comparison with 64 dermatologists

BACKGROUND

The clinical differentiation of face and scalp lesions (FSLs) is challenging even for trained dermatologists. Studies comparing the diagnostic performance of a convolutional neural network (CNN) with dermatologists in FSL are lacking.

METHODS

A market-approved CNN (Moleanalyzer-Pro, FotoFinder Systems) was used for binary classifications of 100 dermoscopic images of FSL. The same lesions were used in a two-level reader study including 64 dermatologists (level I: dermoscopy only; level II: dermoscopy, clinical close-up images, textual information). Primary endpoints were the CNN's sensitivity and specificity in comparison with the dermatologists' management decisions in level II. Generalizability of the CNN results was tested by using four additional external data sets.

RESULTS

The CNN's sensitivity, specificity and ROC AUC were 96.2% [87.0%-98.9%], 68.8% [54.7%-80.1%] and 0.929 [0.880-0.978], respectively. In level II, the dermatologists' management decisions showed a mean sensitivity of 84.2% [82.2%-86.2%] and specificity of 69.4% [66.0%-72.8%]. When fixing the CNN's specificity at the dermatologists' mean specificity (69.4%), the CNN's sensitivity (96.2% [87.0%-98.9%]) was significantly higher than that of dermatologists (84.2% [82.2%-86.2%]; p < 0.001). Dermatologists of all training levels were outperformed by the CNN (all p < 0.001). In confirmation, the CNN's accuracy (83.0%) was significantly higher than dermatologists' accuracies in level II management decisions (all p < 0.001). The CNN's performance was largely confirmed in three additional external data sets but particularly showed a reduced specificity in one Australian data set including FSL on severely sun-damaged skin.

CONCLUSIONS

When applied as an assistant system, the CNN's higher sensitivity at an equivalent specificity may result in an improved early detection of face and scalp skin cancers.

Lentigo Maligna: Clinical Presentation and Appropriate Management

Lentigo maligna (LM) is a type of melanoma in situ that has distinctive characteristics regarding epidemiology, risk factors and clinical features. In addition, LM has a potential to progress to an invasive tumor with potentially aggressive behavior: lentigo maligna melanoma (LMM). Overall, LM has a very good prognosis, whereas LMM has the same prognosis as other invasive melanomas with similar Breslow thickness. LM/LMM represents a challenging entity not only regarding the diagnosis but also regarding the management. Diagnostic criteria are not well established, and there is an overlap of clinical, dermoscopic and pathological features with other benign pigmented skin lesions such as lentigines, pigmented actinic keratoses or macular seborrheic keratoses. LM/LMM's common appearance within photodamaged skin makes lesion border identification difficult. Wide excisions are often required, but since LM/LMM typically appears on cosmetically sensitive areas such as the face, sometimes large excisions are not possible nor desirable. In this sense, specialized approaches have been developed such as margin-controlled surgery or image-guided treatment using reflectance confocal microscopy. Other treatments for LM such as cryosurgery, imiquimod, radiotherapy or photodynamic therapy have been proposed, although recurrence/persistence is common. The current manuscript reviews extensively the published data regarding the diagnosis, treatment and management of both complex entities LM and LMM.

Diagnostic Accuracy of Dermoscopy of Actinic Keratosis: A Systematic Review

INTRODUCTION

Dermoscopy is a tool that aids clinicians in the diagnosis of actinic keratosis; however, few diagnostic accuracy studies have determined its sensitivity and specificity for this diagnosis.

OBJECTIVE

Determine the diagnostic accuracy of dermoscopy on actinic keratosis.

METHODS

A systematic review was conducted on EMBASE, PubMed, Scopus and the Cochrane Central Registry of Controlled Trials from inception to August 2019.

RESULTS

We screened 485 titles and abstracts. Two studies comprising 219 actinic keratoses were eligible for qualitative analysis. The number and heterogeneity of included studies limited a quantitative analysis.

CONCLUSIONS

Studies that focus specifically on the diagnostic accuracy of dermoscopy for actinic keratosis are lacking.

Dermatoscopic features of pigmented intraepidermal carcinoma on the head and neck

BACKGROUND AND OBJECTIVE

Pigmented intraepidermal carcinoma is characterized by dermatoscopic dots and structureless areas, including dots in linear arrangement and by coiled vessels. There are no studies describing the dermatoscopic features of pigmented intraepidermal carcinoma on the head and neck. We aim to characterize the clinical and dermatoscopic appearance of this entity.

PATIENTS AND METHODS

We retrospectively analyzed 79 cases of pigmented intraepidermal carcinoma on the head and neck.

RESULTS

Pigmented intraepidermal carcinoma on the head and neck was characterized dermatoscopically by multiple colors (98.7 %, n = 78), pigmented circles (48.1 %, n = 38), white circles (17.7 %, n = 14), angulated lines (41.8 %, n = 33) and structureless areas (86.1 %, n = 68). Dots in linear arrangement were present in 13.9 % (n = 11). Coiled vessels were present in 7.6 % (n = 6), the dominant vessel type being prominent serpentine vessels (29.2 %, n = 23), thicker and/or redder in color than surrounding vessels, most being in the angular arrangement of the dermal plexus (24.1 %, n = 19).

CONCLUSIONS

Pigmented intraepidermal carcinoma on the head and neck differs from current published descriptions of pigmented intraepidermal carcinoma, reaching statistical significance with a lower incidence of coiled vessels and a higher incidence of pigmented circles, with evident similarities to pigmented actinic keratosis at that location.

[Actinic keratosis]

Actinic keratoses (AK) are common precancerous cutaneous lesions in fair-skinned individuals as a result of cumulative exposure to ultraviolet radiation. Due to their high prevalence, AK account for a large disease burden, in particular in older persons. As AK may potentially progress into invasive cutaneous squamous cell carcinoma, guidelines recommend early and consequent treatment. Numerous lesion- and field-directed interventions with different efficacy and safety profiles are currently licensed in Germany. The appropriate intervention should be chosen together with the patient based on his or her motivation and expectations towards the treatment.

The dermoscopic inverse approach significantly improves the accuracy of human readers for lentigo maligna diagnosis

BACKGROUND

A recently introduced dermoscopic method for the diagnosis of early lentigo maligna (LM) is based on the absence of prevalent patterns of pigmented actinic keratosis and solar lentigo/flat seborrheic keratosis. We term this the inverse approach.

OBJECTIVE

To determine whether training on the inverse approach increases the diagnostic accuracy of readers compared to classic pattern analysis.

METHODS

We used clinical and dermoscopic images of histopathologically diagnosed LMs, pigmented actinic keratoses, and solar lentigo/flat seborrheic keratoses. Participants in a dermoscopy masterclass classified the lesions at baseline and after training on pattern analysis and the inverse approach. We compared their diagnostic performance among the 3 timepoints and to that of a trained convolutional neural network.

RESULTS

The mean sensitivity for LM without training was 51.5%; after training on pattern analysis, it increased to 56.7%; and after learning the inverse approach, it increased to 83.6%. The mean proportions of correct answers at the 3 timepoints were 62.1%, 65.5, and 78.5%. The percentages of readers outperforming the convolutional neural network were 6.4%, 15.4%, and 53.9%, respectively.

LIMITATIONS

The experimental setting and the inclusion of histopathologically diagnosed lesions only.

CONCLUSIONS

The inverse approach, added to the classic pattern analysis, significantly improves the sensitivity of human readers for early LM diagnosis.

In vivo confocal microscopy of dermoscopic suspicious lesions in patients with xeroderma pigmentosum: A cross-sectional study

BACKGROUND

Xeroderma pigmentosum (XP) is a rare genetic disease characterized by extreme photosensitivity, resulting in a higher incidence of cutaneous tumors. Reflectance confocal microscopy (RCM) is a noninvasive imaging method for diagnosing cutaneous lesions.

OBJECTIVE

To explore the application of RCM in the follow-up of patients with XP.

METHODS

Patients with XP underwent RCM for suspicious lesions from January 2010 through April 2019. Lesions with malignant RCM features were excised, and the results were compared with their histopathologic features. Benign lesions on RCM were monitored every 3 months. We recorded the confocal features that were related to malignancy and specifically to melanoma.

RESULTS

A total of 61 suspicious lesions from 13 patients with XP were included. Thirty-three lesions (54%) were malignant (14 melanomas, 15 basal cell carcinomas, and 4 squamous cell carcinomas). Nonvisible papillae (OR, 11.8; 95% CI, 2.6-53.1; P = .001) and atypical cells at the dermoepidermal junction (OR, 11.7; 95% CI, 2.7-50.3; P = .001) were independent predictors of malignancy.

LIMITATIONS

There were limited numbers of patients and lesions. Most cases were retrospectively included, and some did not have a histologic analysis.

CONCLUSIONS

RCM is a valuable tool in the follow-up of patients with XP, reducing the need for excisions by 35%.

Is dermoscopy a good tool for the diagnosis of lentigo maligna and lentigo maligna melanoma? A meta-analysis

Introduction: Dermoscopy is a low-cost examination performed by a dermatologist and good for the diagnosis of pigmented lesions. However, dermoscopy diagnosis of lentigo maligna (LM) and lentigo maligna melanoma (LMM) is still questionable. The objective of this study was to evaluate whether dermoscopy is an effective diagnostic method to diagnose LM/LMM from other pigmented skin lesions, and to identify which are the most frequent dermoscopic criteria associated with LM/LMM

Methods: For this systematic review and meta-analysis, we used the following descriptors: dermoscopy, lentigo maligna, lentigo maligna melanoma, histopathology; and the following databases to search for articles: Cochrane Collaboration, MEDLINE; PMC (PubMed Central) - NIH (National Institutes of Health), EMBASE (The Excerpt Medical Database), and SCISEARCH, from inception to March 30, 2018. The evaluation of studies was performed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies)-2 tool. The PRISMA (Preferred Reporting Itens for Systematic Reviews and Meta-Analyses) and MOOSE (Meta-analysis Of Observational Studies in Epidemiology) guidelines were followed for data extraction. Also, we extracted from each study the dermoscopic criteria most commonly found in the lesions of LM/LMM.

Results: This systematic review included 15 articles for qualitative analysis (a total of 2,012 lesions evaluated) and 7 for meta-analysis. In the bivariate model the mean sensitivity was 0.824 and the mean specificity was 0.835. The area under the curve was 0.889. Rhomboid structures, pseudonetwork, and homogeneous areas were the most frequent dermoscopic criteria associated with LM/LMM.

Conclusion: These findings suggest that dermoscopy has good accuracy in the diagnosis of LM/LMM.

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Key dermoscopic signs in the diagnosis and progression of extrafacial lentigo maligna: Evaluation of a series of 41 cases

BACKGROUND/OBJECTIVES

Lentigo maligna is usually located on the face. Extrafacial lentigo maligna is less common, and diagnosis of early forms is very difficult. Confocal microscopy of facial and extrafacial lentigo maligna shares the same features (abundant dendritic cells and generalised atypical junctional thickenings) and helps us to identify the dermoscopic features of extrafacial lentigo maligna.

METHODS

We analysed dermoscopic and clinical features of 41 lesions diagnosed by confocal microscopy of extrafacial lentigo maligna confirmed on histology to identify dermoscopic signs of early lesions.

RESULTS

Erased areas on dermoscopy were the clue to diagnose early lesions. At the borders of these areas, very small, round or triangular structures were found. At the lesion periphery, dermoscopy revealed a fine reticular pattern that helped to identify them as a melanocytic lesion. A progressive increase of the number and size of erased areas was accompanied by the appearance of various angulated structures around them (angulated lines, zig-zag structures or polygonal structures). Analysis of invasive lesions revealed very large erased areas containing white lines and atypical vascularisation.

CONCLUSIONS

We have identified the dermoscopic early features and signs of progression by examining the dermoscopic and reflectance confocal microscopy findings of early and invasive extrafacial lentigo maligna.

Reflectance confocal microscopy in the diagnosis of pigmented macules of the face: differential diagnosis and margin definition

Here we review the state-of-the-art of RCM morphologic descriptors, standardized terminology, and diagnostic algorithms for the assessment of pigmented macules of the face, for their correct diagnosis and management.

Dermatoscopy of Neoplastic Skin Lesions: Recent Advances, Updates, and Revisions

OPINION STATEMENT

Dermatoscopy (dermoscopy) improves the diagnosis of benign and malignant cutaneous neoplasms in comparison with examination with the unaided eye and should be used routinely for all pigmented and non-pigmented cutaneous neoplasms. It is especially useful for the early stage of melanoma when melanoma-specific criteria are invisible to the unaided eye. Preselection by the unaided eye is therefore not recommended. The increased availability of polarized dermatoscopes, and the extended use of dermatoscopy in non-pigmented lesions led to the discovery of new criteria, and we recommend that lesions should be examined with polarized and non-polarized dermatoscopy. The "chaos and clues algorithm" is a good starting point for beginners because it is easy to use, accurate, and it works for all types of pigmented lesions not only for those melanocytic. Physicians, who use dermatoscopy routinely, should be aware of new clues for acral melanomas, nail matrix melanomas, melanoma in situ, and nodular melanoma. Dermatoscopy should also be used to distinguish between different subtypes of basal cell carcinoma and to discriminate highly from poorly differentiated squamous cell carcinomas to optimize therapy and management of non-melanoma skin cancer. One of the most exciting areas of research is the use of dermatoscopic images for machine learning and automated diagnosis. Convolutional neural networks trained with dermatoscopic images are able to diagnose pigmented lesions with the same accuracy as human experts. We humans should not be afraid of this new and exciting development because it will most likely lead to a peaceful and fruitful coexistence of human experts and decision support systems.

Actinic Keratosis and Non-Invasive Diagnostic Techniques: An Update

Actinic keratosis represents the earliest manifestation of non-melanoma skin cancer. Because of their risk of progression to invasive squamous cell carcinoma, an earlier diagnosis and treatment are mandatory. Their diagnosis sometimes could represent a challenge even for expert dermatologists. Dermoscopy, confocal laser microscopy and optical coherence tomography could help clinicians in diagnosis.

Enhancing Skin Cancer Diagnosis with Dermoscopy

Dermoscopy increases the sensitivity for skin cancer detection, decreases the number of benign lesions biopsied for each malignant diagnosis, and enables the diagnosis of thinner melanomas compared with naked eye examination. Multiple meta-analyses have identified that dermoscopy improves the diagnostic accuracy for melanoma when compared with naked eye examination. In addition, studies have established that dermoscopy can aid in the detection of keratinocyte carcinomas. Dermoscopy triage algorithms have been developed to help novices decide when a biopsy or a referral is most appropriate. In this article, the authors illustrate the dermoscopic features that assist in identifying melanoma and keratinocyte carcinomas.

The value of reflectance confocal microscopy in diagnosis of flat pigmented facial lesions: a prospective study

BACKGROUND

Flat pigmented facial lesions are difficult to diagnose even with dermatoscopy. It is controversial how additional information obtained by in vivo reflectance confocal microscopy (RCM) impacts the diagnosis and management.

OBJECTIVE

To examine what in vivo reflectance confocal microscopy of flat pigmented facial lesions adds to clinical examination using dermatoscopy including digital dermatoscopic monitoring.

METHODS

We prospectively collected 70 cases of flat pigmented facial lesions and recorded diagnoses and management decisions by experts based on direct clinical examination aided by dermatoscopy including digital dermatoscopic monitoring and by remote experts who reviewed the corresponding confocal images. The expert confocal readers were blinded to the clinical and dermatoscopic appearance of the lesion.

RESULTS

The sensitivity of dermatoscopy plus digital dermatoscopic monitoring was 95.0% (95% CI 75.13% to 99.87%) and the specificity was 84.0% (95% CI 70.89% to 92.83%). The sensitivity of RCM was 95.0% (95% CI 75.13% to 99.87%) and the specificity was 82.0% (95% CI 68.56% to 91.42%).

CONCLUSION

Although most flat pigmented facial lesions can be managed by clinical examination and dermatoscopy alone, confocal microscopy is a useful adjunct in selected lesions. If RCM is not correlated with clinical and dermatoscopic information, there is risk of overdiagnosis of actinic keratosis, however.

Dermoscopy of Malignant Skin Tumours: What's New?

Dermoscopy represents a new and effective tool that assists dermatologists in improving the accuracy of clinical diagnosis in onco-dermatology. The aim of this article is to provide an overview of the latest and important dermoscopic progress and observations in this ever-evolving field of dermatology.

Lentigo Maligna, Macules of the Face, and Lesions on Sun-Damaged Skin: Confocal Makes the Difference

Distinguishing lentigo maligna (LM) and lentigo maligna melanoma (LMM) from background pigmented non-melanoma lesions is challenging. The field of solar damage can obscure clinical assessment, and diagnostic ambiguities are created due to the overlap of the clinical features of LM with other benign lesions. Moreover, margin assessment on histology is limited by the resemblance between melanocytic hyperplasia of actinically damaged skin and scattered atypical melanocytes of LM/LMM. Dermoscopy has made a significant contribution but is often not sufficient for diagnosis and margin assessment. Confocal microscopy has become an important complementary tool in enhancing the management of these complex lesions.

Reflectance Confocal Microscopy in Lentigo Maligna

Lentigo maligna is the most common type of facial melanoma. Diagnosis is complicated, however, as it shares clinical and dermoscopic characteristics with other cutaneous lesions of the face. Reflectance confocal microscopy is an imaging technique that permits the visualization of characteristic features of lentigo maligna. These include a disrupted honeycomb pattern and pagetoid cells with a tendency to show folliculotropism. These cells typically have a dendritic morphology, although they may also appear as round cells measuring over 20μm with atypical nuclei. Poorly defined dermal papillae and atypical cells may be seen at the dermal-epidermal junction and can form bridges resembling mitochondrial structures. Other characteristic findings include junctional swelling with atypical cells located around the follicles, resembling caput medusae. Reflectance confocal microscopy is a very useful tool for diagnosing lentigo maligna.

Dermoscopy of difficult-to-diagnose Melanomas

Dermoscopy is a non-invasive procedure that allows the evaluation of cutaneous lesions, and is considered to be a useful tool that improves the diagnostic accuracy of melanoma. Many dermoscopic criteria of melanoma have been established and several algorithms have been created for melanoma detection. However, the recognition of some melanomas remains challenging. Melanomas on specific body sites, melanomas in patients with multiple atypical moles, and nodular melanomas represent the most difficult-to-recognize melanoma subtypes, since they typically lack the “classic” melanoma-specific criteria. This paper provides an update on dermoscopy of difficult-to-diagnose melanomas by summarizing the newest data. Lastly, we highlight the importance of digital dermoscopy in the follow-up of melanocytic lesions for the detection of incipient melanomas while maintaining a low excision rate.