Evaluation of an artificial intelligence-based decision support for the detection of cutaneous melanoma in primary care: a prospective real-life clinical trial.

BACKGROUND: Use of artificial intelligence (AI), or machine learning, to assess dermoscopic images of skin lesions to detect melanoma has, in several retrospective studies, shown high levels of diagnostic accuracy on par with - or even outperforming - experienced dermatologists. However, the enthusiasm around these algorithms has not yet been matched by prospective clinical trials performed in authentic clinical settings. In several European countries, including Sweden, the initial clinical assessment of suspected skin cancer is principally conducted in the primary healthcare setting by primary care physicians, with or without access to teledermoscopic support from dermatology clinics. OBJECTIVES: To determine the diagnostic performance of an AI-based clinical decision support tool for cutaneous melanoma detection, operated by a smartphone application (app), when used prospectively by primary care physicians to assess skin lesions of concern due to some degree of melanoma suspicion. METHODS: This prospective multicentre clinical trial was conducted at 36 primary care centres in Sweden. Physicians used the smartphone app on skin lesions of concern by photographing them dermoscopically, which resulted in a dichotomous decision support text regarding evidence for melanoma. Regardless of the app outcome, all lesions underwent standard diagnostic procedures (surgical excision or referral to a dermatologist). After investigations were complete, lesion diagnoses were collected from the patients' medical records and compared with the app's outcome and other lesion data. RESULTS: In total, 253 lesions of concern in 228 patients were included, of which 21 proved to be melanomas, with 11 thin invasive melanomas and 10 melanomas in situ. The app's accuracy in identifying melanomas was reflected in an area under the receiver operating characteristic (AUROC) curve of 0.960 [95% confidence interval (CI) 0.928-0.980], corresponding to a maximum sensitivity and specificity of 95.2% and 84.5%, respectively. For invasive melanomas alone, the AUROC was 0.988 (95% CI 0.965-0.997), corresponding to a maximum sensitivity and specificity of 100% and 92.6%, respectively. CONCLUSIONS: The clinical decision support tool evaluated in this investigation showed high diagnostic accuracy when used prospectively in primary care patients, which could add significant clinical value for primary care physicians assessing skin lesions for melanoma.

Exploring Patient Pain Experiences during and after Conventional Red Light and Simulated Daylight Photodynamic Therapy for Actinic Keratosis: A Qualitative Interview Study.

Simulated daylight photodynamic therapy is a relatively new and potentially less painful alternative to conventional red light photodynamic therapy for actinic keratosis. Qualitative research exploring patient experiences of pain and skin reactions during these treatments is scarce. To address this, semi-structured interviews were conducted of 10 patients aged 60-81 years with symmetrically distributed actinic keratoses 4 weeks after split-face treatment with conventional red light photodynamic therapy and simulated daylight photodynamic therapy. The participants were recruited from an ongoing clinical randomized trial. Interviews (median length 35 min) were conducted between June 2022 and January 2023, audio-recorded, transcribed verbatim, and analysed qualitatively using content analysis, as described by Graneheim and Lundman. Participants reported that conventional red light photodynamic therapy was very painful during illumination and transiently painful in the post-treatment period, while simulated daylight photodynamic therapy was almost painless during illumination and led to minor post-treatment pain. Also, skin reactions were more intense and longer-lasting with conventional red light photodynamic therapy than with simulated daylight photodynamic therapy. Most participants expressed a treatment preference for simulated daylight photodynamic therapy but had reservations about its unestablished long-term effectiveness. This study underscores the considerable pain associated with conventional red light photodynamic therapy, and the pivotal importance of shared decision-making when selecting the most appropriate treatment.

Incomplete Excision Rate for Lentigo Maligna and Associated Risk Factors.

Standard treatment for lentigo maligna (LM) is surgical excision, yet insights into the frequency of and risk factors for incomplete excisions remain limited. The primary objectives were to assess the incomplete excision rate (IER) in primary LM and to explore potential risk factors for incomplete excisions. A retrospective analysis was conducted encompassing consecutive histopathologically confirmed LMs from 2014-2020. Descriptive statistics were used for LM characteristics and IER, while uni- and multivariate analyses were used for calculating risk factors. The study included 395 LMs with an IER of 16.7% (n = 66). Risk factors for higher incomplete excision rates included: head and neck lesions (p = 0.0014), clinical excision margins < 5 mm (p = 0.040), and utilization of preoperative partial biopsies (p = 0.023). Plastic surgeons had higher IERs than dermatologists (p = 0.036). Lesion diameter (p = 0.20) and surgeon experience (p = 0.20) showed no associations with incomplete excisions, yet LMs with a diameter ≥ 20 mm exhibited higher incomplete excision rates (23.2%) compared witho those < 10 mm (12.9%). LMs should be excised with at least 5-mm clinical margins, especially in the head and neck area. LMs ≥ 20 mm may be more surgically challenging. High-er incomplete excision rates associated with the use of preoperative biopsies and/or plastic surgeons may reflect challenging anatomical locations, larger lesion diameter, and/or ill-defined borders.

Development and Validation of the Oxford Skin Cancer Treatment Scale, a Patient-Reported Outcome Measure for Health-Related Quality of Life and Treatment Satisfaction After Skin Cancer Treatment.

BACKGROUND: Patient-reported outcome measures (PROMs) are necessary to assess the value of skin cancer treatment and to better compare therapeutic options. OBJECTIVE: To develop and validate the Oxford Skin Cancer Treatment (OxSCanTr) scale, evaluating health-related quality of life and satisfaction after skin cancer treatment. MATERIALS AND METHODS: After qualitative patient interviews, international expert consultation, and item reduction, 2 separate patient samples were used to assess the factor structure of the scale. Exploratory factor analysis with categorical variables and a polychoric correlation matrix followed by promax oblique rotation was performed to establish a factor structure on Group A. Confirmatory factor analysis with a Satorra-Bentler scaled test statistic evaluating the root mean squared error of approximation (RMSEA), standardized root mean squared residual (SRMR), and comparative fit index (CFI) was conducted on Group B. Reliability as internal consistency was assessed using McDonald omega. Convergent and discriminant validity were assessed using the Pearson correlation coefficient. RESULTS: A total of 480 subjects returned completed surveys (completion rate 96%). A 12-item scale was developed encompassing 4 domains: aesthetic satisfaction, treatment choice satisfaction, treatment experience, and future concerns regarding recurrence/spread. Confirmatory factor analysis showed excellent goodness-of-fit characteristics, with RMSEA = 0.048, SRMR = 0.051, and CFI = 0.962 using the 4-factor model. Reliability was very good (McDonald omega 0.81-0.82), as was convergent validity with the FACE-Q skin cancer module appraisal of scars subscale (r = 0.55). Discriminant validity with a single question regarding being conservative was similarly excellent (r = -0.02). CONCLUSION: The OxSCanTr scale is a parsimonious, feasible, and valid PROM for the holistic assessment of the experience of patients who have undergone skin cancer treatment.

Dermatoscopic patterns of cutaneous metastases: A multicentre cross-sectional study of the International Dermoscopy Society.

BACKGROUND: The detection of cutaneous metastases (CMs) from various primary tumours represents a diagnostic challenge. OBJECTIVES: Our aim was to evaluate the general characteristics and dermatoscopic features of CMs from different primary tumours. METHODS: Retrospective, multicentre, descriptive, cross-sectional study of biopsy-proven CMs. RESULTS: We included 583 patients (247 females, median age: 64 years, 25%-75% percentiles: 54-74 years) with 632 CMs, of which 52.2% (n = 330) were local, and 26.7% (n = 169) were distant. The most common primary tumours were melanomas (n = 474) and breast cancer (n = 59). Most non-melanoma CMs were non-pigmented (n = 151, 95.6%). Of 169 distant metastases, 54 (32.0%) appeared on the head and neck region. On dermatoscopy, pigmented melanoma metastases were frequently structureless blue (63.6%, n = 201), while amelanotic metastases were typified by linear serpentine vessels and a white structureless pattern. No significant difference was found between amelanotic melanoma metastases and CMs of other primary tumours. CONCLUSIONS: The head and neck area is a common site for distant CMs. Our study confirms that most pigmented melanoma metastasis are structureless blue on dermatoscopy and may mimic blue nevi. Amelanotic metastases are typified by linear serpentine vessels and a white structureless pattern, regardless of the primary tumour.

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

Atypical pigmented facial lesions (aPFLs)-including lentigo maligna (LM) and lentigo maligna melanoma (LMM), solar lentigo (SL), pigmented actinic keratosis (PAK), atypical nevi (AN), seborrheic keratosis (SK) and lichen planus-like keratosis (LPLK)-can exhibit clinical and dermoscopic overlapping features. We aimed to investigate if and how 14 dermoscopic features suggestive for the aforementioned aPFLs vary according to six facial sites among 1197 aPFLs cases (excised to rule out malignancy) along with lesion and patients' metadata. According to distribution and association analysis, aPFLs on the forehead of a male patient aged > 69 years displaying the obliterated follicular openings pattern, appear to be more at risk of malignancy. Of converse, aPFLs of the orbital/cheek/nose area with evident and regular follicular openings with diameter < 10 mm in a female aged below 68 are probably benign. The obliterated follicular openings, keratin plugs, evident and regular follicular openings and target-like pattern features differed significantly among six facial areas in all aPFLs cases. Lesion of the nose may show both features suggestive of malignancy and benignity (e.g. many SL and PAK may display target-like pattern and some LM/LMM cases display keratin plugs and evident and follicular openings), making these features less specific.

Folliculitis Decalvans Has a Heterogeneous Microbiological Signature and Impaired Immunological Response.

BACKGROUND: Folliculitis decalvans (FD) is a rare primary neutrophilic scarring alopecia whose etiology has not been completely elucidated yet. OBJECTIVE: The aim of the study was to determine if the follicular microbiota residing in FD-affected hair follicles had a distinct microbiological signature and if an aberrant immune response was present in the pathogenesis of FD. METHODS: We conducted a cross-sectional study of 10 patients affected by FD. Trichoscopy-guided follicular biopsies were taken from affected and healthy scalp to identify the follicular microbiome using next-generation sequencing. We searched for microbiological biomarkers of FD-affected follicles using the linear discriminant analysis (LDA) effect size (LEfSe) tool. Additionally, peripheral blood mononuclear cells were obtained, and their cytokine production was quantified after incubation with pathogen-associated molecular patterns isolated from patients' biopsies and compared with healthy controls. RESULTS: ß-diversity analysis showed statistically significant differences regarding bacteria comparing follicular microbiota of healthy and FD-affected hairs. Ruminococcaceae, Agathobacter sp., Tyzzerella sp., and Bacteriodales vadin HA21 family were good predictors of disease status. IL-10, TNF-α, and IL-6 levels were significantly decreased in patients after incubation with various strains of bacteria compared with controls. CONCLUSION: FD hair follicles have a specific heterogenous follicular bacterial microbiota signature. Additionally, these patients seem to have an impaired immunological response.

Basal cell carcinoma: Epidemiological impact of clinical versus histopathological diagnosis.

BACKGROUND: Low-risk basal cell carcinomas (BCCs) are to an increasing extent diagnosed by dermatologists through dermoscopic examination only and treated with non-surgical methods. Reports on increasing incidence as well as trends regarding subtypes, anatomical sites and differences related to gender are based solely on histopathologically verified tumours. How unreported clinically diagnosed BCCs affect the epidemiological data has not been sufficiently investigated. OBJECTIVES: To analyse the tumour and patient characteristics of clinically diagnosed versus histopathologically confirmed primary BCCs and to make a gross estimate on how unreported BCCs could influence the total number of new cases. METHODS: We retrospectively reviewed all primary BCCs diagnosed in 2016 at the Department of Dermatology, Sahlgrenska University Hospital in Gothenburg, Sweden. We also reviewed all histopathologically verified primary BCCs at the two largest pathology laboratories in Western Sweden during the same year to estimate the proportion of BCCs diagnosed by dermatologists. RESULTS: In total, 2365 primary BCCs were diagnosed at our centre. More than half of these tumours were clinically diagnosed (55.8%). Superficial subtype (41.7%), location on the trunk (46.3%) and destructive treatment methods (60.0%) were most common. The reports from the two pathology laboratories showed that histopathologically verified BCCs (n = 5837) were more commonly of the infiltrative or nodular subtype and located in the head and neck area. Dermatologists managed 56.0% of them. CONCLUSIONS: This study indicates that a substantial number of BCCs are not visualized in the official statistics which are solely based on reports from pathology laboratories. When taking clinically diagnosed tumours into account, truncal location and superficial subtype are more common than previously believed. Further, based on the regional calculations, the real burden of BCC in Sweden might be up to 70% higher than what is reported in official statistics.

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.

Development and Implementation of a Web-Based International Registry Dedicated to Atypical Pigmented Skin Lesions of the Face: Teledermatologic Investigation on Epidemiology and Risk Factors.

Background: Atypical pigmented facial lesions (aPFLs) often display clinical and dermoscopic equivocal and/or overlapping features, thus causing a challenging and delayed diagnosis and/or inappropriate excisions. No specific registry dedicated to aPFL paired with clinical data is available to date. Methods: The dataset is hosted on a specifically designed web platform. Each complete case was composed of the following data: (1) one dermoscopic picture; (2) one clinical picture; (3) two lesion data, that is, maximum diameter and facial location (e.g., orbital area/forehead/nose/cheek/chin/mouth); (4) patient's demographics: family history of melanoma, history of sunburns in childhood, phototype, pheomelanine, eyes/hair color, multiple nevi/dysplastic nevi on the body; and (5) acquisition device (videodermatoscope/camera-based/smartphone-based system). Results: A total of 11 dermatologic centers contributed to a final teledermoscopy database of 1,197 aPFL with a distribution of 353 lentigo maligna (LM), 146 lentigo maligna melanoma (LMM), 231 pigmented actinic keratoses, 266 solar lentigo, 125 atypical nevi, 48 seborrheic keratosis, and 28 seborrheic-lichenoid keratoses. The cheek site was involved in half of aPFL cases (50%). Compared with those with the other aPFL cases, patients with LM/LMM were predominantly men, older (69.32 ± 12.9 years on average vs. 62.69 ± 14.51), exhibited larger lesions (11.88 ± 7.74 mm average maximum diameter vs. 9.33 ± 6.46 mm), and reported a positive history of sunburn in childhood. Conclusions: The iDScore facial dataset currently represents a precious source of data suitable for the design of diagnostic support tools based on risk scoring classifiers to help dermatologists in recognizing LM/LMM among challenging aPFL in clinical practice.

Evaluation of Melanoma Thickness with Clinical Close-up and Dermoscopic Images Using a Convolutional Neural Network.

Convolutional neural networks (CNNs) have shown promise in discriminating between invasive and in situ melanomas. The aim of this study was to analyse how a CNN model, integrating both clinical close-up and dermoscopic images, performed compared with 6 independent dermatologists. The secondary aim was to address which clinical and dermoscopic features dermatologists found to be suggestive of invasive and in situ melanomas, respectively. A retrospective investigation was conducted including 1,578 cases of paired images of invasive (n = 728, 46.1%) and in situ melanomas (n = 850, 53.9%). All images were obtained from the Department of Dermatology and Venereology at Sahlgrenska University Hospital and were randomized to a training set (n = 1,078), a validation set (n = 200) and a test set (n = 300). The area under the receiver operating characteristics curve (AUC) among the dermatologists ranged from 0.75 (95% confidence interval 0.70-0.81) to 0.80 (95% confidence interval 0.75-0.85). The combined dermatologists' AUC was 0.80 (95% confidence interval 0.77-0.86), which was significantly higher than the CNN model (0.73, 95% confidence interval 0.67-0.78, p = 0.001). Three of the dermatologists significantly outperformed the CNN. Shiny white lines, atypical blue-white structures and polymorphous vessels displayed a moderate interobserver agreement, and these features also correlated with invasive melanoma. Prospective trials are needed to address the clinical usefulness of CNN models in this setting.

Hyperspectral Imaging for Non-invasive Diagnostics of Melanocytic Lesions.

Malignant melanoma poses a clinical diagnostic problem, since a large number of benign lesions are excised to find a single melanoma. This study assessed the accuracy of a novel non-invasive diagnostic technology, hyperspectral imaging, for melanoma detection. Lesions were imaged prior to excision and histopathological analysis. A deep neural network algorithm was trained twice to distinguish between histopathologically verified malignant and benign melanocytic lesions and to classify the separate subgroups. Furthermore, 2 different approaches were used: a majority vote classification and a pixel-wise classification. The study included 325 lesions from 285 patients. Of these, 74 were invasive melanoma, 88 melanoma in situ, 115 dysplastic naevi, and 48 non-dysplastic naevi. The study included a training set of 358,800 pixels and a validation set of 7,313 pixels, which was then tested with a training set of 24,375 pixels. The majority vote classification achieved high overall sensitivity of 95% and a specificity of 92% (95% confidence interval (95% CI) 0.024-0.029) in differentiating malignant from benign lesions. In the pixel-wise classification, the overall sensitivity and specificity were both 82% (95% CI 0.005-0.005). When divided into 4 subgroups, the diagnostic accuracy was lower. Hyperspectral imaging provides high sensitivity and specificity in distinguishing between naevi and melanoma. This novel method still needs further validation.

Measurements of illuminance in simulated daylight photodynamic therapy.

BACKGROUND: Simulated daylight photodynamic therapy (SDL-PDT) is a new treatment alternative for actinic keratosis. The aim of this study was to show how the illuminance that reaches the target skin area during SDL-PDT depends on the spatial positioning of the patient. METHODS: In this technical validation study, illuminance from the SDL-PDT system IndoorLux© was measured at different angles, directions, and distances from the light sources corresponding to potential target skin areas. Using two different photometers, data from 63 measuring points at seven specific distances from the ceiling were collected at 0°, 45°, and 90° angles, respectively. Illuminance levels ≥12,000 lux were regarded as adequate. Hotspots were defined as adequate measurements in all directions at a specific measuring point at distances of 1.3, 1.5, and 1.8 m from the light sources (i.e., the most common patient treatment positions). RESULTS: Adequate illuminance levels were more common with photometer 1 (73%) than photometer 2 (57%). Almost all illuminance levels were adequate at a 0° angle with both photometers. Adequate illuminance levels were observed at 82-93% of the measuring points at a 45° angle and 22-47% at a 90° angle. Hotspots were registered with both photometers at all measuring points at 0°; 59-79% of the measuring points at 45°; and 0-21% at 90°. CONCLUSION: Patient positioning is important during SDL-PDT. Adequate illuminance is achieved if target skin areas are positioned at 0°-45° angles relative to the light sources, but not at 90° angles.

Sun protection behaviour in organ transplant recipients and non-transplant patients attending a dermatology outpatient clinic in Sweden: A questionnaire survey.

BACKGROUND/PURPOSE: Organ transplant recipients (OTRs) are at high risk of developing skin cancer and are therefore advised to protect their skin against ultraviolet radiation from the sun. Specialized OTR clinics with dermatological follow-up may improve sun habits among OTRs. In this study, we compared self-reported sun exposure and sun protection behaviour between OTRs and non-transplant patients (non-TPs) and between OTRs with and without special dermatological follow-up. METHODS: Patients from Sahlgrenska University Hospital, Gothenburg, Sweden, completed a sun exposure questionnaire. Between 2011 and 2015, 282 OTRs transplanted in the period 1976-2014 and 414 non-TPs were recruited among dermatological outpatients. Participants were stratified into five groups by their status as OTRs or non-TPs and by attendance to dermatological follow-up. RESULTS: More non-TPs than OTRs reported one or more sunburns in the past year, 46% vs. 20%, P < .0001). More OTRs with than OTRs without dermatological follow-up reported frequent use of sunscreens (63% vs 44%, P = .006). More OTRs with follow-up used one or more sun protection measure such as covering clothes, than other OTRs (54% vs 34%, P = .016). CONCLUSION: In this study, OTRs reported less sun exposure than non-TPs. Specialized dermatological follow-up seems to improve sun protection behaviour among OTRs. We suggest that specialized OTR clinics should be more broadly implemented.

Vascular Diameter as Clue for the Diagnosis of Clinically and/or Dermoscopically Equivocal Pigmented and Non-Pigmented Basal Cell Carcinomas and Nodular Melanomas.

Background and objectives: Dermoscopy is a useful tool for the early and non-invasive diagnosis of skin malignancies. Besides many progresses, heavily pigmented and amelanotic skin tumors remain still a challenge. We aimed to investigate by dermoscopy if distinctive morphologic characteristics of vessels may help the diagnosis of equivocal nodular lesions. Materials and Methods: A collage of 16 challenging clinical and dermoscopic images of 8 amelanotic and 8 heavily pigmented nodular melanomas and basal cell carcinomas was sent via e-mail to 8 expert dermoscopists. Results: Dermoscopy improved diagnostic accuracy in 40 cases. Vessels were considered the best clue in 71 cases. Focusing on the diameter of vessels improved diagnosis in 5 cases. Conclusions: vascular diameter in addition to morphology and arrangement may be a useful dermoscopic clue for the differential diagnosis of clinically equivocal nodular malignant tumors.

Clinicopathological Factors Associated with Incomplete Excision of High-risk Basal Cell Carcinoma.

Research has shown higher rates of incomplete excision among high-risk than low-risk basal cell carcinomas, but data is limited. A single-centre, retrospective study including excised high-risk basal cell carcinomas (type II-III according to the Swedish classification) was performed to determine incomplete excision rates and associated clinicopathological risk factors. Overall, 987 consecutive cases were included. Of these, 203 (20.6%) were incompletely excised. Incomplete excision rates were higher for type III basal cell carcinomas (27.0% vs 17.6% for type II, p < 0.001) and localization on the face and scalp (22.4% vs 14.7% for other locations, p = 0.009), especially on the nose, ear, scalp and periorbital area (28.0-37.0% vs 9.5-16.9% for other locations, p < 0.0001). Circular excisions were also more often incomplete (28.5%) compared with elliptical excisions (17.7%) (p < 0.001). No association was found between incomplete excision rates and tumour size, excision margins, use of a preoperative biopsy or surgeon experience. Mohs micrographic surgery should be used more often for type II-III basal cell carcinomas on the face and scalp.

Mohs Micrographic Surgery for Primary Versus Recurrent or Incompletely Excised Facial High-risk Basal Cell Carcinomas.

Facial high-risk basal cell carcinomas are preferably treated with Mohs micrographic surgery, but only 10% of patients are offered Mohs micrographic surgery in Sweden. The aim of this retrospective study was to examine the differences between primary and recurrent or incompletely excised facial high-risk basal cell carcinomas undergoing Mohs micrographic surgery, with regard to the number of stages, final defect sizes, reconstructive techniques and other consequences. The study was performed during the period 2012 to 2019 at our centre. A total of 903 basal cell carcinomas in 813 patients (70.1% primary, 10.4% incompletely excised and 19.5% recurrences) were included. The mean number of Mohs micrographic surgery stages was significantly lower for primary basal cell carcinomas compared with recurrences (p = 0.03), and the mean final defect size was significantly smaller in primary basal cell carcinomas compared with both recurrent (p < 0.0001) and incompletely excised (p = 0.003) tumours. Primary basal cell carcinomas tended to more often be reconstructed by primary closure (p = 0.08). Mohs micrographic surgery indications for facial high-risk basal cell carcinomas should be respected and used more frequently on primary basal cell carcinomas, in order to enable better utilization of resources and improved outcomes for the patient.

Incomplete Excisions of Melanocytic Lesions: Rates and Risk Factors.

Incomplete excisions of melanocytic lesions occur despite the intention of complete removal. The aim of this study was to determine the incomplete excision rates for benign and malignant melanocytic lesions and the associated risk factors. Demographic, clinical, and histo-pathological data possibly associated with incomplete excision were collected from 2,782 consecutive excisions between 2014 and 2015. Of these, 269 melanocytic lesions (9.7%) were incompletely excised. Multivariate analysis revealed the following risk factors for significantly higher incomplete excision rates: lesions located in the head and neck area (odds ratio (OR) 3.95, 95% confidence interval (95% CI) 2.35-6.65), surgery performed by general practitioners (OR 3.01, 95% CI 2.16-4.19), the use of a punch excision technique (OR 2.83, 95% CI 1.96-4.08), and excision of non-dysplastic naevi (OR 1.58, 95% CI 1.11-2.23). In conclusion, more caution should be taken when excising melanocytic lesions in the head and neck area, general practitioners require more surgical training, and punch excisions of melanocytic lesions should be avoided.

Interobserver Agreement on Dermoscopic Features and their Associations with In Situ and Invasive Cutaneous Melanomas.

Several melanoma-specific dermoscopic features have been described, some of which have been reported as indicative of in situ or invasive melanomas. To assess the usefulness of these features to differentiate between these 2 categories, a retrospective, single-centre investigation was conducted. Dermoscopic images of melanomas were reviewed by 7 independent dermatologists. Fleiss' kappa (κ) was used to analyse interobserver agreement of predefined features. Logistic regression and odds ratios were used to assess whether specific features correlated with melanoma in situ or invasive melanoma. Overall, 182 melanomas (101 melanoma in situ and 81 invasive melanomas) were included. The interobserver agreement for melanoma-specific features ranged from slight to substantial. Atypical blue-white structures (κ=0.62, 95% confidence interval 0.59-0.65) and shiny white lines (κ=0.61, 95% confidence interval 0.58-0.64) had a substantial interobserver agreement. These 2 features were also indicative of invasive melanomas >1.0 mm in Breslow thickness. Furthermore, regression/peppering correlated with thin invasive melanomas. The overall agreement for classification of the lesions as invasive or melanoma in situ was moderate (κ=0.52, 95% confidence interval 0.49-0.56).

Digital Quantification of Melanocytic Density in Resection Margins of Lentigo Maligna Using SOX10 Versus Hematoxylin-Eosin Staining.

ABSTRACT: Lentigo maligna (LM) represents an overgrowth of atypical melanocytes at the dermal-epidermal junction of chronically sun-damaged skin. The presence of LM on sun-damaged skin poses a diagnostic challenge because the solar-induced melanocytic hyperplasia makes it difficult to assess the LM margins. Melanocytic density can be used to discriminate sun-damaged skin from LM. The aim of this study was to quantify the melanocytic density at the surgical margins of scanned whole-slide images of LM comparing sections stained with H&E and SOX10. Twenty-six surgically excised LM diagnosed at the Department of Pathology at Sahlgrenska University Hospital were collected. The slides that contained the closest surgical margin or harbored the highest density of melanocytes at the margin were selected for serial sectioning using H&E and SOX10. Whole-slide imaging at ×40 magnification was used, and a circular field with a diameter of 0.5 mm at the surgical margin was superimposed on the image. Five blinded pathologists reviewed the slides in a randomized order. In the majority of the cases (24/26), the pathologists identified more melanocytes on the SOX10 slides than those on the H&E slides. On average, 2.5 times more melanocytes were counted using SOX10 compared with H&E (P < 0.05). Furthermore, the average group SD on the H&E slides was 4.12 compared with 2.83 on the SOX10 slides (P = 0.004). Thus, the use of SOX10 staining leads to higher melanocytic density counts compared with H&E staining when assessing the surgical margins of LM. The use of SOX10 staining also significantly decreased the interobserver variability between pathologists.