Negative pigment network and shiny white streaks: a dermoscopic-pathological correlation study.

It has been suggested that both negative pigment network (NPN) and shiny white streaks (SWS) were related to an increase of dermal collagen. To study precisely the dermoscopic-histopathologic correlation of NPN and SWS, we have performed a dermoscopic-pathological correlation study. A total of 25 skin lesions dermoscopically characterized by the presence of NPN and/or SWS, including histopathologically confirmed dermatofibroma (2), Spitz nevus (3), compound nevus (6), dysplastic nevus (7), and melanoma (7), were evaluated for the presence of NPN, SWS, and blue-white veil. The histopathologic features such as orthokeratosis, orthokeratosis plus nests of pigmented melanocytes at the junction, hypergranulosis, hypergranulosis plus nests of pigmented melanocytes at the junction, epidermal invagination plus orthokeratosis, fibrosis, lamellar fibrosis, and elongation and bridging of rete ridges were evaluated. We found a disagreement in 80% of skin lesions between NPN and fibrosis (P = 0.02). For SWS, a significant agreement emerged with hypergranulosis (76%; P = 0.01), and the same occurred with fibrosis (80%; P = 0.01). Moreover, blue-white veil also displayed a significant agreement with hypergranulosis (68%; P = 0.04). Our findings confirm the correlation of SWS with fibrosis, whereas a clear-cut histopathologic substrate of NPN could not be established.

Prompt-driven Latent Domain Generalization for Medical Image Classification.

Deep learning models for medical image analysis easily suffer from distribution shifts caused by dataset artifact bias, camera variations, differences in the imaging station, etc., leading to unreliable diagnoses in real-world clinical settings. Domain generalization (DG) methods, which aim to train models on multiple domains to perform well on unseen domains, offer a promising direction to solve the problem. However, existing DG methods assume domain labels of each image are available and accurate, which is typically feasible for only a limited number of medical datasets. To address these challenges, we propose a unified DG framework for medical image classification without relying on domain labels, called Prompt-driven Latent Domain Generalization (PLDG). PLDG consists of unsupervised domain discovery and prompt learning. This framework first discovers pseudo domain labels by clustering the bias-associated style features, then leverages collaborative domain prompts to guide a Vision Transformer to learn knowledge from discovered diverse domains. To facilitate cross-domain knowledge learning between different prompts, we introduce a domain prompt generator that enables knowledge sharing between domain prompts and a shared prompt. A domain mixup strategy is additionally employed for more flexible decision margins and mitigates the risk of incorrect domain assignments. Extensive experiments on three medical image classification tasks and one debiasing task demonstrate that our method can achieve comparable or even superior performance than conventional DG algorithms without relying on domain labels. Our code is publicly available at https://github.com/SiyuanYan1/PLDG/tree/main.

Treatment goals for moderate to severe psoriasis: an Australian consensus.

BACKGROUND/OBJECTIVES: The high incidence of comorbidities in patients with psoriasis, significant impact on quality of life and patients' dissatisfaction with treatment led a European group to develop a consensus position on psoriasis treatment goals. There is an evident need for similar treatment goals in Australia. The aim of this project was to develop Australian treatment goals that reflect the local environment. METHODS: A panel of 12 representatives was drawn from across Australia consisting of nine dermatologists and a rheumatologist, a dermatology nurse and a general practitioner (GP)/dermatology trainee. The group met on three occasions between September 2011 and March 2012. The panel undertook a literature review and critically examined available evidence-based treatment goals. A questionnaire relating to psoriasis assessment and specific treatment outcomes was developed. Following discussion and debate, recommended treatment goals for psoriasis patients in Australia were determined. RESULTS: The panel agreed by consensus on recommended psoriasis treatment goals in the Australian environment. There was recognition that in addition to psoriasis area severity index (PASI) assessment, a quality of life assessment was highly relevant in determining psoriasis severity and treatment outcome. Mild psoriasis was defined as PASI ≤ 10 and a dermatology life quality index (DLQI) ≤ 10, with moderate to severe psoriasis defined as PASI > 10 and/or DLQI > 10. The presence of certain definedclinical features would elevate a patient's classification from mild to moderate/severe. The target for treatment was defined as a maintained change in PASI ≥ 75% improvement and DLQI ≤ 5. These largely concurred with the European treatment goals. A flow chart for psoriasis management in Australia based on outcome measures was developed. CONCLUSIONS: There is a need to identify and articulate treatment goals for psoriasis. Assessment of psoriasis severity requires both physical scoring (PASI) and consideration of quality of life measures (DLQI). Identification of treatment goals will guide clinicians in treatment decision-making, enhance the availability and appropriate use of therapies and increase patient satisfaction with their care.

Dermoscopy, reflectance confocal microscopy and histopathology of an amelanotic melanoma from an individual heterozygous for MC1R and tyrosinase variant alleles.

We present a case of an amelanotic nodular melanoma occurring in a 26-year-old woman who carried a heterozygous (melancortin-1-receptor) MC1R 160R/W and tyrosinase (TYR) 402R/Q genotype and had a dark hair phenotype. We present dermoscopic, reflectance confocal microscopy (RCM) and histopathological images of the melanoma. We discuss the relationship between MC1R red hair colour (RHC) variants, TYR variants, phenotype and melanoma development. We also discuss the merits of RCM as an additional diagnostic aid for equivocal melanocytic lesions.

The daily use of dermoscopy in the Netherlands

Background: Dermoscopy is a well-established tool for the diagnosis of skin diseases and skin cancer. Data on the use of dermoscopy by Dutch dermatologists is lacking. Objectives: To identify factors influencing the use of dermoscopy in daily dermatology practice and compare the results with those from other European countries. Materials & Methods: As a part of a pan-European study, all registered dermatologists in the Netherlands were asked to complete an online survey regarding questions about training and attitude towards dermoscopy. Results: Valid answers were collected from 213 respondents (out of 475 registered dermatologists), of whom 99% reported using dermoscopy. Of those, 41% reported dermoscopy training during residency. A high level of dermoscopy use for different types of skin diseases was reported by 28.9%. Users considered dermoscopy useful for pigmented lesions, especially for the early diagnosis of melanoma, but less advantageous for inflammatory diagnoses. Seventy-three percent reported that dermoscopy increased the number of melanomas detected compared to naked eye diagnosis, and two-thirds reported a decrease in unnecessary biopsies of benign lesions. Almost one third reported that on at least one occasion, a lesion that appeared benign on dermoscopy proved to be a melanoma after excision. Conclusion: This study reveals that nearly all Dutch dermatologists use dermoscopy, particularly for melanocytic lesions, but less so for inflammatory diagnoses. Most believe that they detected more melanomas as a result of using dermoscopy compared to the naked eye. A high level of dermoscopy use was significantly associated with seeing more skin cancer patients each month compared to infrequent use.

Dermatoscopy of genital warts.

BACKGROUND: Genital warts may mimic a variety of conditions, thus complicating their diagnosis and treatment. The recognition of early flat lesions presents a diagnostic challenge. OBJECTIVE: We sought to describe the dermatoscopic features of genital warts, unveiling the possibility of their diagnosis by dermatoscopy. METHODS: Dermatoscopic patterns of 61 genital warts from 48 consecutively enrolled male patients were identified with their frequencies being used as main outcome measures. RESULTS: The lesions were examined dermatoscopically and further classified according to their dermatoscopic pattern. The most frequent finding was an unspecific pattern, which was found in 15/61 (24.6%) lesions; a fingerlike pattern was observed in 7 (11.5%), a mosaic pattern in 6 (9.8%), and a knoblike pattern in 3 (4.9%) cases. In almost half of the lesions, pattern combinations were seen, of which a fingerlike/knoblike pattern was the most common, observed in 11/61 (18.0%) cases. Among the vascular features, glomerular, hairpin/dotted, and glomerular/dotted vessels were the most frequent finding seen in 22 (36.0%), 15 (24.6%), and 10 (16.4%) of the 61 cases, respectively. In 10 (16.4%) lesions no vessels were detected. Hairpin vessels were more often seen in fingerlike (χ(2) = 39.31, P = .000) and glomerular/dotted vessels in knoblike/mosaic (χ(2) = 9.97, P = .008) pattern zones; vessels were frequently missing in unspecified (χ(2) = 8.54, P = .014) areas. LIMITATIONS: Only male patients were examined. CONCLUSIONS: There is a correlation between dermatoscopic patterns and vascular features reflecting the life stages of genital warts; dermatoscopy may be useful in the diagnosis of early-stage lesions.

Prevalence of Skin Cancer and Related Skin Tumors in High-Risk Kidney and Liver Transplant Recipients in Queensland, Australia.

The increased skin cancer incidence in organ transplant recipients is well-known, but the skin cancer burden at any one time is unknown. Our objective was to estimate the period prevalence of untreated skin malignancy and actinic keratoses in high-risk kidney and liver transplant recipients and to assess associated factors. Organ transplant recipients underwent full skin examinations by dermatologically trained physicians. The proportion of examined organ transplant recipients with histopathologically confirmed skin cancer in the 3-month baseline period was estimated. Prevalence ratios with 95% confidence intervals indicated significant associations. Of 495 high-risk organ transplant recipients (average age = 54 years, time immunosuppressed = 8.9 years), 135 (27%) had basal cell carcinoma, squamous cell carcinoma or Bowen's disease (intraepidermal carcinoma) present and confirmed in the baseline period, with respective prevalence proportions of 10%, 11%, and 18% in kidney transplant recipients and 10%, 9%, and 13% in liver transplant recipients. Over 80% had actinic keratosis present, with approximately 30% having 5 or more actinic keratoses. Organ transplant recipients with the highest skin cancer burden were Australian born, were fair skinned (prevalence ratio = 1.61, 95% confidence interval = [1.07, 2.43]), reported past skin cancer (prevalence ratio =3.39, 95% confidence interval = [1.93, 5.95]), and were receiving the most frequent skin checks (prevalence ratio = 1.76, 95% confidence interval = [1.15, 2.70]). In conclusion, high-risk organ transplant recipients carry a substantial measurable skin cancer burden at any given time and require frequent review through easily accessible, specialized services.

A mutation in the Cdon gene potentiates congenital nevus development mediated by NRAS(Q61K).

Congenital nevi develop before birth and sometimes cover large areas of the body. They are presumed to arise from the acquisition of a gene mutation in an embryonic melanocyte that becomes trapped in the dermis during development. Mice bearing the Cdk4(R24C) ::Tyr-NRAS(Q) (61K) transgenes develop congenital nevus-like lesions by post-natal day 10, from melanocytes escaping the confines of hair follicles. We interbred these mice with the collaborative cross (CC), a resource that enables identification of modifier genes for complex diseases (those where multiple genes are involved). We examined variation in nevus cell density in 66 CC strains and mapped a large-effect quantitative trait locus (QTL) controlling nevus cell density to murine chromosome 9. The best candidate for a gene that exacerbates congenital nevus development in the context of an NRAS mutation is Cdon, a positive regulator of sonic hedgehog (Shh) that is expressed mainly in keratinocytes.