“String of pearls pattern”: report of three cases of non clear-cell acanthoma

bstract: The coiled and dotted vessels in a serpiginous arrangement or “string of pearls” is considered a classical vascular pattern associated with clear cell acanthoma. We present three cases of epidermal tumors different from clear cell acanthoma that have the same “string of pearls” vascular pattern. Even though most authors keep considering the “string of pearls” vascular pattern an almost pathognomonic sign of clear-cell acanthoma, the cases presented here suggest that some other epidermal tumors can also show this pattern. Kewbords: Acanthoma; Dermoscopy; Keratosis, seborrhei

Dermoscopic Features of Actinic Cheilitis and Other Common Inflammatory Cheilitis: A Multicentric Retrospective Observational Study by the International Dermoscopy Society

Background: Clinical differentiation between different cheilitis variants may be difficult. Application of mucoscopy, in addition to clinical background, could provide additional diagnostic clues facilitating initial patient management. Objectives: To determine mucoscopic clues differentiating actinic cheilitis from the main forms of inflammatory cheilitis, including eczematous cheilitis, discoid lupus erythematosus, and lichen planus of the lips. Methods: This was a retrospective, multicenter study being a part of an ongoing project "Mucoscopy - an upcoming tool for oral mucosal disorders" under the aegis of the International Dermoscopy Society. Cases included in the current study were collected via an online call published on the IDS website (www.dermoscopy-ids.org) between January 2019 and December 2020. Results: Whitish-red background was found in actinic cheilitis as well as in cheilitis due to discoid lupus erythematous and lichen planus. Polymorphous vessels were more likely to be seen in actinic cheilitis compared to other causes of cheilitis. White scales, ulceration, and blood spots predominated in actinic cheilitis and lichen planus, whereas yellowish scales typified eczematous and discoid lupus erythematous cheilitis. Radiating white lines although most common in lichen planus patients were also seen in actinic cheilitis. Conclusion: Despite differences in the frequency of mucoscopic structures, we have not found pathognomonic features allowing for differentiation between analyzed variants of cheilitis

A reinforcement learning model for AI-based decision support in skin cancer

: We investigated whether human preferences hold the potential to improve diagnostic artificial intelligence (AI)-based decision support using skin cancer diagnosis as a use case. We utilized nonuniform rewards and penalties based on expert-generated tables, balancing the benefits and harms of various diagnostic errors, which were applied using reinforcement learning. Compared with supervised learning, the reinforcement learning model improved the sensitivity for melanoma from 61.4% to 79.5% (95% confidence interval (CI): 73.5-85.6%) and for basal cell carcinoma from 79.4% to 87.1% (95% CI: 80.3-93.9%). AI overconfidence was also reduced while simultaneously maintaining accuracy. Reinforcement learning increased the rate of correct diagnoses made by dermatologists by 12.0% (95% CI: 8.8-15.1%) and improved the rate of optimal management decisions from 57.4% to 65.3% (95% CI: 61.7-68.9%). We further demonstrated that the reward-adjusted reinforcement learning model and a threshold-based model outperformed naïve supervised learning in various clinical scenarios. Our findings suggest the potential for incorporating human preferences into image-based diagnostic algorithms

Dermoscopy of Infectious Dermatoses (Infectiouscopy) in Skin of Color—A Systematic Review by the International Dermoscopy Society “Imaging in Skin of Color” Task Force

Dermoscopy has been showed to facilitate the non-invasive recognition of several infectious disorders (infectiouscopy) thanks to the detection of peculiar clues. Although most of the knowledge on this topic comes from studies involving light-skinned patients, there is growing evidence about its use also in dark phototypes. This systematic literature review summarizes published data on dermoscopy of parasitic, bacterial, viral and fungal dermatoses (dermoscopic findings, used setting, pathological correlation, and level of evidence of studies) and provides a homogeneous terminology of reported dermoscopic features according to a standardized methodology. A total of 66 papers addressing 41 different dermatoses (14 bacterial, 5 viral, 11 fungal infections, and 11 parasitoses/bites and stings) and involving a total of 1096 instances were included in the analysis. The majority of them displayed a level of evidence of V (44 single case reports and 21 case series), with only 1 study showing a level of evidence of IV (case-control analysis). Moreover, our analysis also highlighted a high variability in the terminology used in the retrieved studies. Thus, although promising, further studies designed according to a systematic and standardized approach are needed for better characterization of dermoscopy of infectious skin infections

Dermoscopy of Hair and Scalp Disorders (Trichoscopy) in Skin of Color—A Systematic Review by the International Dermoscopy Society “Imaging in Skin of Color” Task Force

Hair and scalp disorders are of significant interest for physicians dealing with dark phototypes due to their prevalence and potential aesthetic impact resulting from a higher tendency for scarring. In order to facilitate their non-invasive diagnosis, several dermoscopic studies have been published, yet data are sparse and no systematic analysis of the literature has been performed so far. This systematic literature review summarizes published data on trichoscopy of hair and scalp diseases (trichoscopic findings, used setting, pathological correlation, and level of evidence of studies). A total of 60 papers addressing 19 different disorders (eight non-cicatricial alopecias, nine cicatricial alopecias, and two hair shaft disorders) were assessed, for a total of 2636 instances. They included one cross-sectional analysis, 20 case-control studies, 25 case-series, and 14 single case-reports, so the level of evidence was V and IV in 65% and 33% of cases, respectively, with only one study showing a level of evidence of III. Notably, although there is a considerable body of literature on trichoscopy of hair/scalp diseases, our review underlined that potentially significant variables (e.g., disease stage or hair texture) are often not taken into account in published analyses, with possible biases on trichoscopic patterns, especially when it comes to hair shaft changes. Further analyses considering all such issues are therefore needed

Dermoscopy of Cutaneous Neoplasms in Skin of Color – A Systematic Review by the International Dermoscopy Society “Imaging in Skin of Color” Task Force

Over the last few decades, dermoscopy has been showed to facilitate the non-invasive diagnosis of both benign and malignant skin tumors, yet literature data mainly comes from studies on light phototypes. However, there is growing evidence that skin neoplasms may benefit from dermoscopic assessment even for skin of color. This systematic literature review evaluated published data in dark-skinned patients (dermoscopic features, used setting, pathological correlation, and level of evidence of studies), also providing a standardized and homogeneous terminology for reported dermoscopic findings. A total of 20 articles describing 46 different tumors (four melanocytic neoplasms, eight keratinocytic tumors, 15 adnexal cutaneous neoplasms, seven vascular tumors, four connective tissue tumors, and eight cystic neoplasms/others) for a total of 1724 instances were included in the analysis. Most of them showed a level of evidence of V (12 single case reports and six case series), with only two studies featuring a level of evidence of IV (case-control analysis). Additionally, this review also underlined that some neoplasms and phototypes are underrepresented in published analyses as they included only small samples and mainly certain tones of “dark skin” spectrum (especially phototype IV). Therefore, further studies considering such limitations are required for a better characterization

Dermoscopy of Inflammatory Dermatoses (Inflammoscopy) in Skin of Color—A Systematic Review by the International Dermoscopy Society “Imaging in Skin of Color” Task Force

Dermoscopic patterns of inflammatory dermatoses (inflammoscopy) have been extensively studied in the recent years, though data on patients with darker phototypes (IV-VI) are sparse. The aims of this systematic review were to summarize the current state of knowledge on inflammoscopy applied to skin of color and provide a standardized nomenclature of reported findings. Besides dermoscopic features, type of setting and magnification, number of cases, and histopathological correlation were analyzed. Eighty-five papers addressing 76 different dermatoses (25 papulosquamous dermatoses, 19 hyperpigmented dermatoses, seven hypopigmented dermatoses, four granulomatous dermatoses, two sclerotic dermatoses, five facial inflammatory dermatoses, and 14 miscellaneous conditions) for a total of 2073 instances were retrieved. Only one study showed a level of evidence of III (cross-sectional study), whereas 10 and 74 displayed a level of evidence of IV (case-control studies) and V (case-series and case-reports), respectively. Moreover, our analysis also highlighted that most of papers focalized on a limited number of dermatoses, with several conditions having only single dermoscopic descriptions. Additionally, few studies compared findings among phototypes belonging to the “skin of color” spectrum. Further studies designed according to a systematic approach and considering the above-mentioned issues are therefore needed

Basosquamous carcinoma: dermoscopic clues to diagnosis

Basosquamous carcinoma (BSC) is a rare skin cancer which has areas of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) and a transition zone between them. However, dermoscopic features of BSC are not well described in the published work, except one study. The aim of the present study was to better identify and clarify the dermoscopic findings of BSC in the largest group of patients in the published work and to describe its dermoscopic features according to histopathologically BCC-dominant, SCC-dominant and intermediate categories. Dermoscopic features of 36 histopathologically proven BSC and their dermatopathological correlates were retrospectively analyzed. Dermoscopic features were evaluated by pattern analysis. Keratin mass (91.7%) was the most common dermoscopic feature. Surface scaling (77.8%), ulceration (69.4%), white structureless areas (69.4%), white clods (66.7%) and blood spots on keratin mass (66.7%) were the other frequent findings. Polymorphous vascular pattern consisting of various combinations of branched, serpentine, straight, coiled or looped vessels were detected in 61% of the lesions. BSC has BCC-dominant vascular features together with otherwise SCC-dominant morphology, the common pattern seen in BSC lesions being BCC-dominant polymorphous or monomorphous vasculature, together with dermoscopic findings of keratinization. White circles, known to be a valuable clue to SCC and keratoacanthoma, were present at the same magnitude in BSC in our study. The observed histological correlation of eosinophilic keratin overlying the epithelium which lined follicular infundibulae in these tumors, provides a plausible new perspective on dermoscopic white circles

Dermatopathological characteristics of dermatofibromas from dermatoscopic clues

Background: Several types of dermatofibroma (DF) have been identified dermatopathologically and with dermatoscopic correlation, the dermatopathology has been predictable in limited studies so far. We identify DFs with specific dermatoscopic structures and determine the respective dermatopathological correlates. Methods: Dermatoscopic and dermatopathologic correlation of 403 DFs were assessed. A pattern analysis algorithm was used for the dermatoscopic evaluation, each lesion being evaluated according to 10 dermatoscopic patterns with further subdivision of the atypical subtype according and their dermatoscopic similarities to other defined skin lesions. Results: Dermatoscopic pattern analysis showed typical patterns in 83.4% of DFs with atypical patterns in 16.6%. We classified the atypical DFs according to their dermatoscopic similarity to certain lesions: Melanoma-like 2.7%, basal cell carcinoma-like 0.7%, keratoacanthoma-like 0.5%, seborrheic keratosis-like 2.7%; nevus-like 1.5%; nevus sebaceous-like 0.9%; xanthogranuloma-like 0.5%; pyogenic granuloma-like 0.5%; and spitzoid 6.5%. Dermatopathologically 12 subtypes of DFs were identified. It was found that the most common pattern found in fibrocollagenous DFs was the typical pattern with peripheral reticular lines and central white structureless area (32.9%) whereas non-fibrocollagenous types were more likely to have atypical patterns (65.1%). Conclusions: Our study resulted in new conclusions while supporting some previous findings. The fact that the pathogenesis of DF involves a reactive inflammatory process with fibrosis is likely to have diverse effects on dermatoscopic morphology. If atypical dermatoscopic patterns are identified in suspected DF, excisional biopsy may be prudent