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Zusammenfassung Hintergrund, Anamnese und Untersuchungen Das Amelanotische Melanom (AM) ist ein Subtyp des Melanoms, bei dem die Melanozyten wenig oder keine Melaninsynthese betreiben. Da es klinisch nicht die typische, dunkle Pigmentierung des Melanoms zeigt, wird es oftmals als gutartiger Hauttumor oder entzündliche Dermatose verkannt und daher zu spät oder fehlerhaft behandelt. Diese Übersicht aus 4 Fällen dient der Veranschaulichung der Warnzeichen von plantaren AM (PAM), die jedem klinisch tätigen Mediziner bekannt sein sollten. Therapie und Verlauf Wir präsentieren eine Fallserie aus 4 Patienten mit PAM und beschreiben detailliert die Bandbreite des klinischen Erscheinungsbildes sowie den Krankheitsverlauf. Folgerung PAM können verschiedene klinische Ausprägungen annehmen und insbesondere ältere Patienten mit multiplen Nebenerkrankungen sind gefährdet für eine Fehldiagnose. Wir empfehlen daher generell eine diagnostische Biopsie bei jeder plantaren Ulzeration, wenn diese nach 6 Wochen kein Therapieansprechen zeigt.

Advances in biomedical artificial intelligence may introduce or perpetuate sex and gender discriminations. Convolutional neural networks (CNN) have proven a dermatologist-level performance in image classification tasks but have not been assessed for sex and gender biases that may affect training data and diagnostic performance. In this study, we investigated sex-related imbalances in training data and diagnostic performance of a market-approved CNN for skin cancer classification (Moleanalyzer Pro®, Fotofinder Systems GmbH, Bad Birnbach, Germany).We screened open-access dermoscopic image repositories widely used for CNN training for distribution of sex. Moreover, the sex-related diagnostic performance of the market-approved CNN was tested in 1549 dermoscopic images stratified by sex (female n = 773; male n = 776).Most open-access repositories showed a marked under-representation of images originating from female (40%) versus male (60%) patients. Despite these imbalances and well-known sex-related differences in skin anatomy or skin-directed behaviour, the tested CNN achieved a comparable sensitivity of 87.0% [80.9%-91.3%] versus 87.1% [81.1%-91.4%], specificity of 98.7% [97.4%-99.3%] versus 96.9% [95.2%-98.0%] and ROC-AUC of 0.984 [0.975-0.993] versus 0.979 [0.969-0.988] in dermoscopic images of female versus male origin, respectively. In the sample at hand, sex-related differences in ROC-AUCs were not statistically significant in the per-image analysis nor in an additional per-individual analysis (p ≥ 0.59).Design and training of artificial intelligence algorithms for medical applications should generally acknowledge sex and gender dimensions. Despite sex-related imbalances in open-access training data, the diagnostic performance of the tested CNN showed no sex-related bias in the classification of skin lesions.

Conventional photodynamic therapy (c-PDT) is a highly effective treatment for actinic keratoses. Besides pain as the main side effect, blood pressure (BP) increases and hypertensive crises may occur during treatment. Reducing the irradiation intensity while keeping the total dose constant (low-irradiance PDT) can achieve a clinically relevant reduction in pain. This study aimed to evaluate the influence of li-PDT on the BP and pulse (PR) during therapy and the incidence of post-interventional hypertension compared with c-PDT.We retrospectively analyzed the treatment data of 79 patients (39 c-PDT and 40 li-PDT). BP and PR measurements were performed in all patients before PDT, at mid-exposure, and immediately after PDT. In addition, the pain was assessed by using the visual analog scale.Patients treated with li-PDT reported significantly lower pain than those receiving c-PDT (p .0005). Additionally, they showed less systolic (SBP) and diastolic (DBP) BP increase (∆SBP: p .0005, ∆DBP: p = .015) and overall lower absolute BP values (SBP: p .0005, DBP: p = .008) compared with c-PDT. They were also significantly less likely to develop post-interventional hypertension (p = .037) or higher stages of arterial hypertension. Regarding PR, there was no difference in absolute values between both groups, but the increase from onset to half irradiation duration was significantly higher in c-PDT (p = .013).Li-PDT is an excellent option to reduce the elevation of arterial BP and decrease the incidence of post-interventional hypertension and hypertensive crisis. This finding has considerable relevance, especially with the risk profile of many PDT patients in mind (advanced age and cardiovascular history).

ZusammenfassungMetabolische Anpassungsprozesse, vermittelt durch sog. Hypoxie-induzierbare Faktoren und deren Zielgene, spielen in zahlreichen Malignomen eine wichtige Rolle. Rasch wachsende Tumoren können ihre Stoffwechselvorgänge an eine auftretende Hypoxie anpassen. So werden beispielsweise nach der Aktivierung des „Hypoxia inducible-factors-1α“ Modifikationen am Glukosestoffwechsel, der intrazellulären pH-Regulation oder der Angiogenese initiiert. In dieser immunhistochemischen Pilotstudie analysierten wir primär kutane Melanome mit positivem und negativem Schildwächterlymphknotenstatus im Hinblick auf mögliche Unterschiede ihrer metabolischen Signatur. Hierbei konnten wir unter anderem zeigen, dass die Expression von Glukosetransporter‑1 (GLUT-1) sowohl in allen Melanomen ohne Subgruppenanalyse, als auch in der Subgruppe mit negativem Schildwächterlymphknoten positiv mit der Tumordicke sowie dem Vorliegen einer Ulzeration korrelierte. Zudem korrelierte bei Melanomen mit positivem Schildwächterlymphknoten die Expression von vaskulärem endothelialem Wachstumsfaktor (VEGF) positiv mit dem Vorliegen einer Ulzeration.

Background Sequential digital dermoscopy (SDD) is applied for early melanoma detection by uncovering dynamic changes of monitored lesions. Convolutional neural networks (CNN) are capable of high diagnostic accuracies similar to trained dermatologists. Objectives To investigate the capability of CNN to correctly classify melanomas originally diagnosed by mere dynamic changes during SDD. Methods A retrospective cross-sectional study using image quartets of 59 high-risk patients each containing one melanoma diagnosed by dynamic changes during SDD and three nevi (236 lesions). Two validated CNN classified quartets at baseline or after SDD follow-up at the time of melanoma diagnosis. Moreover, baseline quartets were rated by 26 dermatologists. The main outcome was the number of quartets with correct classifications. Results CNN-1 correctly classified 9 (15.3%) and CNN-2 8 (13.6%) of 59 baseline quartets. In baseline images, CNN-1 attained a sensitivity of 25.4% (16.1%–37.8%) and specificity of 92.7% (87.8%–95.7%), whereas CNN-2 of 28.8% (18.8%–41.4%) and 75.7% (68.9%–81.4%). Expectedly, after SDD follow-up CNN more readily detected melanomas resulting in improved sensitivities (CNN-1: 44.1% [32.2%–56.7%]; CNN-2: 49.2% [36.8%–61.6%]). Dermatologists were told that each baseline quartet contained one melanoma, and on average, correctly classified 24 (22–27) of 59 quartets. Correspondingly, accepting a baseline quartet to be appropriately classified whenever the highest malignancy score was assigned to the melanoma within, CNN-1 and CNN-2 correctly classified 28 (47.5%) and 22 (37.3%) of 59 quartets, respectively. Conclusions The tested CNN could not replace the strategy of SDD. There is a need for CNN capable of integrating information on dynamic changes into analyses.

Background: Psoriasis is a chronic and systemic inflammatory disease with a loss of up to 5 life years, which is thought to be reduced by biologic treatment. Disease severity and eligibility for systemic treatment are often based on the cutaneous psoriasis area and severity index (PASI) with a cut-off of 10 in several European countries. However, it is unclear how well this cut-off reflects systemic inflammation and, consequently, the risk for the development of comorbidity. Objectives: (1) To assess whether specific PASI thresholds, in particular PASI 10, predict elevated biomarkers of systemic inflammation and cardiovascular risk on an individual patient level. (2) To assess the association of PASI and psoriatic arthritis with biomarkers of systemic inflammation and cardiovascular risk. Methods: Retrospective cross-sectional study of 72 psoriasis patients without systemic treatment. Results: Overall, 68, 42, and 50% of patients had cardiovascular risk level neutrophil-to-lymphocyte ratio (NLR), C-reactive protein, and elevated platelet-to-lymphocyte ratio (PLR) values, respectively. The respective positive predictive values of PASI 10 were 70, 45, and 70. The performance of the optimal PASI cut-offs according to the Youden index was similarly weak. Subgrouping of patients with a PASI below 10 did not result in a considerably improved reflection of systemic inflammation. PLR was significantly higher in patients with moderate-to-severe compared to mild psoriasis and significantly correlated with PASI in patients with a PASI above 2 (rs = 0.266, n = 64). NLR was significantly higher in patients with psoriatic arthritis. Conclusion: Specific PASI thresholds were not well suited to predict elevated biomarkers of systemic inflammation and cardiovascular risk on an individual patient level. Therefore, PASI, and possibly other purely cutaneous measures, may not be ideal as stand-alone parameters to define disease severity and eligibility for systemic treatment. Our results are relevant for the ongoing discussion on the definition of psoriasis severity and eligibility for systemic treatment. Further research addressing the added value of a set of biomarkers of systemic inflammation in the assessment of psoriasis severity would be desirable.

Background Psoriasis is considered an independent cardiovascular risk factor, evidentially driving atherosclerosis. However, little is known about changes in the microvasculature of non-lesional skin in psoriasis patients. This study systematically examined capillary pathologies in psoriasis patients by digital video nailfold capillaroscopy. Patients and methods Prospective study comparing nailfold capillaries of psoriasis patients with those of healthy controls. Nailfold capillaries were evaluated for 21 parameters and results were correlated with characteristics of patients and psoriatic disease, laboratory parameters, and measurements of carotid intima-media thickness. Results 77 psoriasis patients (24 patients with additional psoriatic arthritis) and 71 controls were well-matched for demographic features and for relevant confounding factors causing microangiopathy. In comparison with controls, psoriasis patients showed a significant loss of capillaries, capillary expansion with increased ramifications and tortuosity and capillary irregularities. Moreover, in psoriasis patients we found significantly elevated serum markers of inflammation and significantly increased intima-media-thickness measurements. We found no effect of disease duration nor disease activity on capillary changes. Conclusions Nailfold capillaries of psoriasis patients showed marked microvascular abnormalities accompanied by increased markers of systemic inflammation and atherosclerosis. Prospective cohort studies are needed to assess the role of nailfold capillaroscopy for predicting the cardiovascular risk of psoriasis patients.

Functional skin barrier requires sphingolipid homeostasis; 3-ketodihydrosphingosine reductase or KDSR is a key enzyme of sphingolipid anabolism catalyzing the reduction of 3-ketodihydrosphingosine to sphinganine. Biallelic mutations in the KDSR gene may cause erythrokeratoderma variabilis et progressive-4, later specified as PERIOPTER syndrome, emphasizing a characteristic periorifical and ptychotropic erythrokeratoderma. We report another patient with compound heterozygous mutations in KDSR, born with generalized harlequin ichthyosis, which progressed into palmoplantar keratoderma. To determine whether patient-associated KDSR mutations lead to KDSR substrate accumulation and/or unrecognized sphingolipid downstream products in stratum corneum (SC), we analyzed lipids of this and previously published patients with non-identical biallelic mutations in KDSR. In SC of both patients, we identified ‘hitherto’ unobserved skin ceramides with an unusual keto-type sphingoid base in lesional and non-lesional areas, which accounted for up to 10% of the measured ceramide species. Furthermore, an overall shorter mean chain length of free and bound sphingoid bases was observed—shorter mean chain length of free sphingoid bases was also observed in lesional psoriasis vulgaris SC, but not generally in lesional atopic dermatitis SC. Formation of keto-type ceramides is probably due to a bottle neck in metabolic flux through KDSR and a bypass by ceramide synthases, which highlights the importance of tight intermediate regulation during sphingolipid anabolism and reveals substrate deprivation as potential therapy.

Metabolic reprogramming mediated by hypoxia-inducible factors play a crucial role in many human cancers. HIF-1α is activated under hypoxic conditions and is considered a key regulator of oxygen homoeostasis during tumor proliferation under hypoxia. Aim of this research was to analyze the immunohistochemical expression of HIF-1α, VEGF-A, Glut-1, MCT4, and CAIX in atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). 21 paraffin-embedded AFX and 22 PDS were analysed by immunohistochemistry, namely HIF-1α, VEGF-A (referred to as VEGF throughout the manuscript), Glut-1, MCT4, and CAIX. To quantify the protein expression, we considered the percentage of positive tumor cells (0: 0%, 1: up to 1%, 2: 2-10%, 3: 11-50%, 4:50%) in relation to the staining intensity (0: negative, 1: low, 2: medium, 3: strong). HIF-1α expression (mean ± SD) in AFX (9.33±2.92) was significantly stronger than that in PDS (5.90±4.38; P= 0.007), whereas the expression of VEGF, Glut-1, MCT4, and CAIX did not show differences between AFX and PDS. When comparing all tumors without subgroup stratification, the expression of HIF-1α (P= 0.044) and MCT4 (P= 0.036) was significantly stronger in ulcerated tumors than in tumors without ulceration. Our findings provide the first evidence that HIF-1α-induced metabolic reprogramming may contribute to the pathogenesis of AFX and PDS. HIF-1α expression seems to be higher in AFX than in PDS, and ulcerated tumors show higher expression levels of HIF-1α and MCT4 irrespective of the diagnosis.

The healing phase of contact hypersensitivity reactions is critically dependent on regulatory T cells (Tregs), but even the early inflammatory phase, that is, 6-24 hours after induction of a contact hypersensitivity reaction, is susceptible to Treg-mediated suppression. To investigate the underlying mechanisms, we injected Tregs before the challenge and analyzed the skin-infiltrating cells as early as 6 hours later. Early on, we found mainly neutrophils in the challenged skin, but only a few T cells. This influx of neutrophils was blocked by the injection of Tregs, indicating that they were able to prevent the first wave of leukocytes, which are responsible for starting an immune reaction. As an underlying mechanism, we identified that Tregs can tighten endothelial junctions by inducing intracellular cAMP, leading to protein kinase A-RhoA‒dependent signaling. This eventually reorganizes endothelial junction proteins, such as Notch3, Nectin 2, Filamin B, and VE-cadherin, all of which contribute to the tightening of the endothelial barrier. In summary, Tregs prevent the leakage of proinflammatory cells from and into the tissue, which establishes a mechanism to downregulate immune reactions.

BACKGROUND AND OBJECTIVES Convolutional neural networks (CNN) enable accurate diagnosis of medical images and perform on or above the level of individual physicians. Recently, collective human intelligence (CoHI) was shown to exceed the diagnostic accuracy of individuals. Thus, diagnostic performance of CoHI (120 dermatologists) versus individual dermatologists versus two state-of-the-art CNN was investigated. PATIENTS AND METHODS Cross-sectional reader study with presentation of 30 clinical cases to 120 dermatologists. Six diagnoses were offered and votes collected via remote voting devices (quizzbox®, Quizzbox Solutions GmbH, Stuttgart, Germany). Dermatoscopic images were classified by a binary and multiclass CNN (FotoFinder Systems GmbH, Bad Birnbach, Germany). Three sets of diagnostic classifications were scored against ground truth: (1) CoHI, (2) individual dermatologists, and (3) CNN. RESULTS CoHI attained a significantly higher accuracy [95 % confidence interval] (80.0 % [62.7 %-90.5 %]) than individual dermatologists (75.7 % [73.8 %-77.5 %]) and CNN (70.0 % [52.1 %-83.3 %]; all P

HINTERGRUND UND ZIELE Systeme kunstlicher Intelligenz (durch "deep learning" faltende neuronale Netzwerke; engl. convolutional neural networks, CNN) erreichen inzwischen bei der Klassifikation von Hautlasionen vergleichbar gute Ergebnisse wie Dermatologen. Allerdings mussen die Limitationen solcher Systeme vor flachendeckendem klinischem Einsatz bekannt sein. Daher haben wir den Einfluss des "dunklen Rand-Artefakts" (engl. dark corner artefact; DCA) in dermatoskopischen Bildern auf die diagnostische Leistung eines CNN mit Marktzulassung zur Klassifikation von Hautlasionen untersucht. PATIENTEN UND METHODEN Ein Datensatz aus 233 Bildern von Hautlasionen (60 maligne und 173 benigne) ohne DCA (Kontrolle) wurde digital so modifiziert, dass kleine, mittlere oder grose DCA zu sehen waren. Alle 932 Bilder wurden dann mittels CNN mit Marktzulassung (Moleanalyzer-Pro® , FotoFinder Systems) auf Malignitatsscores hin analysiert. Das Spektrum reichte von 0-1; ein Score von > 0,5 wurde als maligne klassifiziert. ERGEBNISSE In der Kontrollserie ohne DCA erreichte das CNN eine Sensitivitat von 90,0 % (79,9 %-95,3 %), eine Spezifitat von 96,5 % (92,6 %-98,4 %) sowie eine Flache unter der Kurve (AUC, area under the curve) der "receiver operating characteristic" (ROC) von 0,961 (0,932-0,989). In den Datensatzen mit kleinen beziehungsweise mittleren DCA war die diagnostische Leistung vergleichbar. In den Bildersatzen mit grosen DCA wurden allerdings signifikant hohere Malignitatsscores erzielt. Dies fuhrte zu einer signifikant verminderten Spezifitat (87,9 % [82,2 %-91,9 %], P

ZusammenfassungUnter dem Begriff Pseudolymphom (PSL) versteht man eine benigne, reaktive Lymphoproliferation der Haut, die klinisch und/oder histologisch ein malignes Lymphom simulieren kann. Die genaue Ätiopathogenese ist bis heute nicht gänzlich geklärt. Man unterscheidet die primären, idiopathischen PSL ohne erkennbare Ursache von den sekundären PSL mit bekanntem Stimulus. Wir berichten über das Auftreten von Pseudolymphomen nach einer Behandlung mit medizinischen Blutegeln (Hirudotherapie). Bisher wurden nach bestem Wissen und Gewissen insgesamt nur 9 Fälle von kutanen PSL nach Hirudotherapie in der Literatur beschrieben.

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.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.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.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.

Purpose Uveal melanoma (UM) is an orphan cancer of high unmet medical need. Current patterns of care and surveillance remain unclear as they are situated in an interdisciplinary setting. Methods A questionnaire addressing the patterns of care and surveillance in the management of patients with uveal melanoma was distributed to 70 skin cancer centers in Austria, Germany and Switzerland. Frequency distributions of responses for each item of the questionnaire were calculated. Results 44 of 70 (62.9%) skin cancer centers completed the questionnaire. Thirty-nine hospitals were located in Germany (88.6%), three in Switzerland (6.8%) and two in Austria (4.5%). The majority (68.2%) represented university hospitals. Most patients with metastatic disease were treated in certified skin cancer centers (70.7%, 29/41). Besides, the majority of patients with UM were referred to the respective skin cancer center by ophthalmologists (87.2%, 34/39). Treatment and organization of follow-up of patients varied across the different centers. 35.1% (14/37) of the centers stated to not perform any screening measures. Conclusion Treatment patterns of patients with uveal melanoma in Germany, Austria and Switzerland remain extremely heterogeneous. A guideline for the treatment and surveillance is urgently needed.

ZusammenfassungChronische Prurigo ist durch anhaltenden Pruritus, teils einhergehend mit sekundären Kratzläsionen, gekennzeichnet. Die Abklärung der Genese ist von besonderem Stellenwert, wobei eine atopische Diathese häufig einen ätiologischen Faktor darstellt. Wir präsentieren einen Patienten mit chronischem Pruritus multifaktorieller Genese (atopische Diathese, chronische Niereninsuffizienz, Diabetes mellitus, Polyneuropathie). Nach multiplen erfolglosen Vortherapien behandelten wir den Patienten mit Dupilumab, worunter sich ein sehr positiver Erkrankungsverlauf mit deutlicher Besserung der Lebensqualität zeigte.