Perifollicular linear projections: A dermatoscopic criterion for the diagnosis of lentigo maligna on the face.

BACKGROUND: Lentigo maligna (LM) can mimic benign, flat, pigmented lesions and can be challenging to diagnose. OBJECTIVE: To describe a new dermatoscopic feature termed "perifollicular linear projections (PLP)" as a diagnostic criterion for LM on the face. METHODS: Retrospective study on reflectance confocal microscopy and dermatoscopy images of flat facial pigmented lesions originating from 2 databases. PLP were defined as short, linear, pigmented projections emanating from hair follicles. Dermatoscopy readers were blinded to the final histopathologic diagnosis. RESULTS: From 83 consecutive LMs, 21/83 (25.3%) displayed "bulging of hair follicles" on reflectance confocal microscopy and 18 of these 21 (85.7%), displayed PLP on dermatoscopy. From a database of 2873 consecutively imaged and biopsied lesions, 252 flat-pigmented facial lesions were included. PLP was seen in 47/76 melanomas (61.8%), compared with 7/176 lesions (3.9%) with other diagnosis (P < .001). The sensitivity was 61.8% (95% CI, 49.9%-72.7%), specificity 96.0% (95% CI, 92.9%-98.4%). PLP was independently associated with LM diagnosis on multivariate analysis (OR 26.1 [95% CI, 9.6%-71.0]). LIMITATIONS: Retrospective study. CONCLUSION: PLP is a newly described dermatoscopic criterion that may add specificity and sensitivity to the early diagnosis of LM located on the face. We postulate that PLP constitutes an intermediary step in the LM progression model.

The use of game-based learning strategies for dermatology and dermoscopy education: a cross-sectional study by the International Dermoscopy Society (IDS) survey.

INTRODUCTION: Dermoscopy is a valuable tool in the diagnosis of various skin conditions. Dermoscopy increases the sensitivity and specificity for skin cancer diagnosis, as well as infectious, inflammatory, and hair diseases. However, mastering dermoscopy intricacies poses challenges. In this context, innovative educational methods are sought, including game-based learning (GBL) strategies. OBJECTIVE: To describe current perceptions, knowledge and usage of GBL strategies in dermoscopy education; and identify strengths and challenges to enhance their utilization. METHODS: This was a cross-sectional study conducted by the International Dermoscopy Society (IDS). A web-based survey with 25-questions was distributed among the IDS members between October 2022 and April 2023. Responses were collected and analyzed using SPSS Statistics 26. RESULTS: A total of 801 responses were received. Of these, 46.6% responders were unfamiliar with gamification and serious games. Among those acquainted, 56.3% reported using GBL strategies for education. Younger participants were more likely to use GBL strategies (p = 0.015). Participants familiar with GBL believed it enhances medical education (78.5%) but not as a sole replacement for traditional methods (96%). For dermoscopy education, 22.2% had used GBL strategies, with Kahoot (35.5%) and You Dermoscopy (24.1%) being the most commonly used. Respondents found gaming strategies to be fun (95%), motivating (91%), and valuable for e-learning (94%). CONCLUSION: Results from this survey demonstrate favorable perception towards GBL strategies in dermatology education, including dermoscopy. While there are ongoing challenges in validation, GBL strategies are promising and valuable tools that can aid the learning and teaching experience. Addressing implementation barriers and validating existing games could optimize GBL's impact on dermatology education.

Gamified learning in dermatology and dermoscopy education: a paradigm shift.

Teaching methods in medical education have been changing. More recent teaching modalities have gone beyond the traditional delivery of knowledge, promoting learning motivation, and improving teaching and learning outcomes. 'Gamification' and 'serious games' are methodologies that use the principles of games to facilitate learning processes and the acquisition of skills and knowledge, thereby improving attitudes towards learning when compared with traditional teaching methods. As dermatology is a visual field, images are a key component of different teaching strategies. Likewise, dermoscopy, a noninvasive diagnostic technique that allows the visualization of structures within the epidermis and upper dermis, also uses images and pattern recognition strategies. A series of Apps using game-based strategy have been created to teach and facilitate dermoscopy learning; however, studies are required to demonstrate their effectiveness. This review summarizes the current evidence of game-based learning strategies in medical education, including dermatology and dermoscopy.

Skin cancer: Primary, secondary, and tertiary prevention. Part I.

Skin cancer is the most commonly diagnosed cancer worldwide. Understanding the natural history of skin cancer provides the framework for the creation of prevention and control strategies that aim to reduce the skin cancer burden. Based on the target (individual vs population), disease stage, and risk factors (modifiable vs nonmodifiable), strategies can be categorized into 4 levels-health promotion (also known as primordial prevention), primary prevention, secondary prevention, and tertiary prevention. This is the first of a 2-part review, which will cover the epidemiology, risk factors, primordial prevention, and primary prevention of melanoma and keratinocyte skin cancers. In particular, we highlight preventive strategies centered on mitigating the impact of modifiable risk factors and potential interventions for health promotion and primary prevention of skin cancer. Summaries of existing recommendations, challenges, opportunities, and future directions are also discussed.

Skin cancer: Primary, secondary, and tertiary prevention. Part II.

Skin cancer is the most commonly diagnosed cancer worldwide. Understanding the natural history of skin cancer will provide a framework for the creation of prevention and control strategies that aim to reduce skin cancer burden. The strategies include health promotion, primary prevention, secondary prevention, and tertiary prevention. Health promotion and primary prevention were covered in the first part of this 2-part review. The second part covers the secondary and tertiary prevention of skin cancer. In particular, preventive strategies centered on the early detection of skin cancer, the prevention of disease progression, clinical surveillance, and educational and behavioral interventions are highlighted. The summaries of existing recommendations, challenges, opportunities, and future directions are discussed.

Results of the 2016 International Skin Imaging Collaboration International Symposium on Biomedical Imaging challenge: Comparison of the accuracy of computer algorithms to dermatologists for the diagnosis of melanoma from dermoscopic images.

BACKGROUND: Computer vision may aid in melanoma detection. OBJECTIVE: We sought to compare melanoma diagnostic accuracy of computer algorithms to dermatologists using dermoscopic images. METHODS: We conducted a cross-sectional study using 100 randomly selected dermoscopic images (50 melanomas, 44 nevi, and 6 lentigines) from an international computer vision melanoma challenge dataset (n = 379), along with individual algorithm results from 25 teams. We used 5 methods (nonlearned and machine learning) to combine individual automated predictions into "fusion" algorithms. In a companion study, 8 dermatologists classified the lesions in the 100 images as either benign or malignant. RESULTS: The average sensitivity and specificity of dermatologists in classification was 82% and 59%. At 82% sensitivity, dermatologist specificity was similar to the top challenge algorithm (59% vs. 62%, P = .68) but lower than the best-performing fusion algorithm (59% vs. 76%, P = .02). Receiver operating characteristic area of the top fusion algorithm was greater than the mean receiver operating characteristic area of dermatologists (0.86 vs. 0.71, P = .001). LIMITATIONS: The dataset lacked the full spectrum of skin lesions encountered in clinical practice, particularly banal lesions. Readers and algorithms were not provided clinical data (eg, age or lesion history/symptoms). Results obtained using our study design cannot be extrapolated to clinical practice. CONCLUSION: Deep learning computer vision systems classified melanoma dermoscopy images with accuracy that exceeded some but not all dermatologists.

Host-seeking activity of a Tanzanian population of Anopheles arabiensis at an insecticide treated bed net.

BACKGROUND: Understanding how mosquitoes respond to long lasting insecticide treated nets (LLINs) is fundamental to sustaining the effectiveness of this essential control tool. We report on studies with a tracking system to investigate behaviour of wild anophelines at an LLIN, in an experimental hut at a rural site in Mwanza, Tanzania. METHODS: Groups of adult female mosquitoes (n = 10 per replicate) reared from larvae of a local population, identified as predominantly (95%) Anopheles arabiensis, were released in the hut. An infrared video tracking system recorded flight and net contact activity over 1 h as the mosquitoes attempted to reach a supine human volunteer within a bed net (either a deltamethrin-treated LLIN or an untreated control net). A range of activities, including flight path, position in relation to the bed net and duration of net contact, were quantified and compared between treatments. RESULTS: The total time that female An. arabiensis spent in flight around LLINs was significantly lower than at untreated nets [F(1,10) = 9.26, p = 0.012], primarily due to a substantial reduction in the time mosquitoes spent in persistent 'bouncing' flight [F(1,10) = 18.48, p = 0.002]. Most activity occurred at the net roof but significantly less so with LLINs (56.8% of total) than untreated nets [85.0%; Χ2 (15) = 234.69, p < 0.001]. Activity levels at the bed net directly above the host torso were significantly higher with untreated nets (74.2%) than LLINs [38.4%; Χ2 (15) = 33.54, p = 0.004]. 'Visiting' and 'bouncing' rates were highest above the volunteer's chest in untreated nets (39.9 and 50.4%, respectively) and LLINs [29.9 and 42.4%; Χ2 (13) = 89.91, p < 0.001; Χ2 (9) = 45.73, p < 0.001]. Highest resting rates were above the torso in untreated nets [77%; Χ2 (9) = 63.12, p < 0.001], but in LLINs only 33.2% of resting occurred here [Χ2 (9) = 27.59, p = 0.001], with resting times spread between the short vertical side of the net adjacent to the volunteer's head (21.8%) and feet (16.2%). Duration of net contact by a single mosquito was estimated at 204-290 s on untreated nets and 46-82 s on LLINs. While latency to net contact was similar in both treatments, the reduction in activity over 60 min was significantly more rapid for LLINs [F(1,10) = 6.81, p = 0.026], reiterating an 'attract and kill' rather than a repellent mode of action. CONCLUSIONS: The study has demonstrated the potential for detailed investigations of behaviour of wild mosquito populations under field conditions. The results validate the findings of earlier laboratory studies on mosquito activity at LLINs, and reinforce the key role of multiple brief contacts at the net roof as the critical LLIN mode of action.

Clinico-morphological features of BRAF inhibition-induced proliferative skin lesions in cancer patients.

BACKGROUND: The use of BRAF inhibitors may lead to the development of cutaneous toxicities such as rashes, photosensitivity, alopecia, palmoplantar erythrodysesthesia, and proliferative skin lesions, including keratoacanthomas (KAs) and cutaneous squamous cell carcinomas (cuSCCs). The latter are noteworthy for their potential to exhibit malignant features, and they may necessitate invasive treatment. Their prompt identification is of primary importance for directing supportive care efforts and maintaining dose intensity while minimizing the morbidity associated with supportive care interventions. Because such lesions are less familiar to oncologists, this study was designed to characterize their clinico-morphological features, which have not been hitherto described. METHODS: The clinical and dermoscopic characteristics and risk factors of new-onset proliferative skin lesions (benign verrucous lesions and KAs/cuSCCs) developing after the initiation of treatment with vemurafenib, dabrafenib, and XL281 were analyzed; the histopathological diagnoses were ascertained. RESULTS: The majority of the lesions were benign verrucous lesions (78%, n = 87), whereas KAs/cuSCCs represented 22% (n = 25). The median times to biopsy for the initial verrucous lesions and KAs/cuSCCs were 4.8 and 10.5 weeks, respectively. The clinico-morphological features significant for KAs/cuSCCs included a larger size (P < .001), a nodular appearance (P < .001), a central keratin plug (P < .001), a central ulceration or crust (P = .04), an adherent scale (P = .02), an erythematous halo (P = .03), and a scaly ring (collarette; P < .001) at the periphery. CONCLUSIONS: Our findings represent the first detailed description of the clinico-morphological characteristics that permit distinction between the benign and malignant skin lesions induced by BRAF inhibitors. They are valuable for the recognition of lesions that require intervention and/or a dermatology referral versus those that permit provisional monitoring.

Clinical and dermoscopic characteristics of melanomas on nonfacial chronically sun-damaged skin.

BACKGROUND: Melanomas on chronically sun-damaged skin (CSDS) can be difficult to identify and often manifest morphologic features that overlap with benign lesions. OBJECTIVE: We describe and analyze the clinical and dermoscopic characteristics of melanomas on nonfacial CSDS. METHODS: Melanoma cases on nonfacial CSDS were retrospectively identified from the biopsy specimen logs of 6 melanoma clinics. Clinical and dermoscopic images were combined into 1 database. Demographics, clinical, dermoscopic, and histopathologic information were analyzed. Descriptive frequencies were calculated. RESULTS: One hundred eighty-six cases met the inclusion criteria: 142 melanomas in situ (76%) and 39 invasive (21%; mean thickness, 0.49 mm). Lentigo maligna was the most common histopathologic subtype (n = 76; 40.9%). The most frequent dermoscopic structures were granularity (n = 126; 67.7%) and angulated lines (n = 82; 44%). Vascular structures were more frequent in invasive melanomas (56% vs 12% of in situ melanomas). Most manifested 1 of 3 dermoscopic patterns: patchy peripheral pigmented islands, angulated lines, and tan structureless with granularity pattern. LIMITATIONS: This was a retrospective study, and evaluators were not blinded to the diagnosis. In addition, interobserver concordance and sensitivity and specificity for dermoscopic structures were not evaluated. CONCLUSION: Outlier lesions manifesting dermoscopic structures, such as granularity, angulated lines, or vessels and any of the 3 described dermoscopic patterns should raise suspicion for melanoma.

'Do UC the melanoma?' Recognising the importance of different lesions displaying unevenness or having a history of change for early melanoma detection.

BACKGROUND/OBJECTIVES: Many melanomas are of a diameter smaller than 6 mm and may lack classical asymmetry, border irregularity and colour variegation (ABCD). The objectives of this article are to characterise the fidelity of melanomas diagnosed in a high-risk clinic to the ABCD and to review potential methods for early clinical detection of melanoma. METHODS: All cases of primary melanoma diagnosed by one clinician at the Memorial Sloan-Kettering Cancer Center over the past 11 years were evaluated for the presence of the ABCD. The melanomas were analysed for asymmetry of contour, unevenness in distribution of colours and textures, border irregularity, number of colours present and diameter. RESULTS: In all, 236 melanomas were analysed. Of these, asymmetry of contour was present in 65% and 94% demonstrated unevenness in the distribution of colours and textures. The borders were regular in 12% of the melanomas and colour variegation was present in 63%. In total, 28% of the lesions were small, with a diameter less than 6 mm. This study was limited by the subjectivity of clinical lesion analysis. CONCLUSION: We put forward for your consideration a new mnemonic: 'Do UC (different, uneven, changing) the melanoma?' This mnemonic encompasses differential, analytical and comparative cognition strategies for an enhanced early detection of melanoma.

Dermoscopic structures and patterns used in melanoma detection.

Melanoma is the leading cause of skin cancer-related deaths. Yet, early detection remains the most cost-effective means of preventing death from melanoma. Early detection can be achieved by a physician and/or the patient (also known as a self-skin exam). Skin exams performed by physicians are further enhanced using dermoscopy. Dermoscopy is a non-invasive technique that allows for the visualization of subsurface structures that are otherwise not visible to the naked eye. Evidence demonstrates that dermoscopy improves the diagnostic accuracy for skin cancer, including melanoma; it decreases the number of unnecessary skin biopsies of benign lesions and improves the benign-to-malignant biopsy ratio. Yet, these improvements are contingent on acquiring dermoscopy training. Dermoscopy is used by clinicians who evaluate skin lesions and perform skin cancer screenings. In general, under dermoscopy nevi tend to appear as organized lesions, with one or two structures and colors, and no melanoma-specific structures. In contrast, melanomas tend to manifest a disorganized pattern, with more than two colors and, usually, at least one melanoma-specific structure. This review is intended to familiarize the reader with the dermoscopic structures and patterns used in melanoma detection.

Is primary breast melanoma a true pathological entity? The argument against it.

Background: Previous studies have reported cases of primary melanoma of the breast parenchyma (PMBP), but the pathogenesis of this disease remains poorly understood. We review the presentation and outcomes of reported cases and provide detailed pathological analysis of four additional cases. Furthermore, we discuss potential theories regarding the pathogenesis of this clinical presentation. Results: We identified 29 published studies (n = 95 patients) and report four new cases (n = 99). Ninety-one (92 %) patients were female, with a median age of 50 years. Previous skin melanomas were reported by 56 % of patients, with the trunk being the most common location (32.7 %) followed by the upper extremities (20 %). The most common tumor location reported (n = 73) was the right (49 %) upper outer quadrant (56 %). The median time from skin melanoma diagnosis to the presence of a breast mass was 65 months (1-192). Nodal status at presentation was reported in n = 67 (68 %) patients. Of these, positive nodal metastases were seen in 40.3 %, while distant metastatic disease at presentation was reported in 30 % of patients. Surgery was performed in 66 %, being partial mastectomy (PM) the most common procedure in 82 %. Adjuvant therapy was described in 38 patients. The reported (n = 12) median survival was 11.5 (1-70) months. Conclusion: Melanomas identified in the breast parenchyma are likely the result of nodal or hematogenous spread from previously known or unknown melanomas, and should not be considered as PMBP. Management should be multidisciplinary, including surgical excision aimed at obtaining negative margins with lymphadenectomy of clinically positive nodes and neoadjuvant/adjuvant immunotherapy.

Expert Agreement on the Presence and Spatial Localization of Melanocytic Features in Dermoscopy.

Dermoscopy aids in melanoma detection; however, agreement on dermoscopic features, including those of high clinical relevance, remains poor. In this study, we attempted to evaluate agreement among experts on exemplar images not only for the presence of melanocytic-specific features but also for spatial localization. This was a cross-sectional, multicenter, observational study. Dermoscopy images exhibiting at least 1 of 31 melanocytic-specific features were submitted by 25 world experts as exemplars. Using a web-based platform that allows for image markup of specific contrast-defined regions (superpixels), 20 expert readers annotated 248 dermoscopic images in collections of 62 images. Each collection was reviewed by five independent readers. A total of 4,507 feature observations were performed. Good-to-excellent agreement was found for 14 of 31 features (45.2%), with eight achieving excellent agreement (Gwet's AC >0.75) and seven of them being melanoma-specific features. These features were peppering/granularity (0.91), shiny white streaks (0.89), typical pigment network (0.83), blotch irregular (0.82), negative network (0.81), irregular globules (0.78), dotted vessels (0.77), and blue-whitish veil (0.76). By utilizing an exemplar dataset, a good-to-excellent agreement was found for 14 features that have previously been shown useful in discriminating nevi from melanoma. All images are public (www.isic-archive.com) and can be used for education, scientific communication, and machine learning experiments.