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1.
Am J Dermatopathol ; 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32675472

RESUMO

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.

2.
Nat Med ; 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32572267

RESUMO

The rapid increase in telemedicine coupled with recent advances in diagnostic artificial intelligence (AI) create the imperative to consider the opportunities and risks of inserting AI-based support into new paradigms of care. Here we build on recent achievements in the accuracy of image-based AI for skin cancer diagnosis to address the effects of varied representations of AI-based support across different levels of clinical expertise and multiple clinical workflows. We find that good quality AI-based support of clinical decision-making improves diagnostic accuracy over that of either AI or physicians alone, and that the least experienced clinicians gain the most from AI-based support. We further find that AI-based multiclass probabilities outperformed content-based image retrieval (CBIR) representations of AI in the mobile technology environment, and AI-based support had utility in simulations of second opinions and of telemedicine triage. In addition to demonstrating the potential benefits associated with good quality AI in the hands of non-expert clinicians, we find that faulty AI can mislead the entire spectrum of clinicians, including experts. Lastly, we show that insights derived from AI class-activation maps can inform improvements in human diagnosis. Together, our approach and findings offer a framework for future studies across the spectrum of image-based diagnostics to improve human-computer collaboration in clinical practice.

3.
Acta Derm Venereol ; 100(13): adv00188, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32488285

RESUMO

Cutaneous squamous cell carcinoma (SCC) is the second most common type of cancer in Swedish men and women. The incidence of SCC is increasing rapidly. Primary treatment is complete surgical excision with sufficient margins to avoid recurrence and metastasis. The aim of this retrospective study was to identify the clinicopathological factors associated with incomplete excision of SCCs. Clinicopathological data and surgical outcome was obtained for 691 SCCs excised during a 2-year period (2014 to 2015) in Gothenberg, Sweden. Overall, 81 SCCs (11.7%) were incompletely excised. Incomplete excisions were associated with physician specialty and experience, tumour localization in the head and neck region, larger tumour diameter, and lower grade of tumour differentiation. However, multiple regression analysis revealed that large tumour size and excisions carried out by general practitioners were the only factors that significantly negatively affected rates of incomplete excision. These results should be taken into consideration when excising SCCs, in order to avoid multiple excisions.

5.
Dermatol Pract Concept ; 9(3): 195-199, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31384492

RESUMO

Background: General practitioners (GPs) are often the first point of contact for Swedish patients seeking medical advice for skin lesions of concern, but many lack training in dermoscopy. Objective: To examine the effects of a 1-day training course in dermoscopy among Swedish GPs. Methods: The intervention group consisted of GPs who underwent a 1-day training course in dermoscopy and a control group that did not undergo any education. Before the training course, the intervention group performed a test consisting of 30 dermoscopy cases including 9 different benign and malignant melanocytic and nonmelanocytic diagnoses. The participants then took the same test directly after the course and again after 6 months. The control group took the same test twice with a 6-month interval in between tests in order to avoid recall bias. Results: Twenty-seven GPs in the intervention group took the test before and immediately after the course with an improvement of their median test scores by 8 points (13 vs 20 correct answers, P < 0.01). Eighteen participants also took the test a third time after 6 months with similar results compared with the second test (median scores of 20.5 vs 20.0, P = 0.3). In the control group, 16 persons preformed both tests with an improvement of their median score by 2 points (13.5 vs 15.5 correct answers, P = 0.06). Conclusions: The results of this study show positive effects on diagnostic accuracy in a test situation among GPs receiving a 1-day training course in dermoscopy.

7.
Lancet Oncol ; 20(7): 938-947, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31201137

RESUMO

BACKGROUND: Whether machine-learning algorithms can diagnose all pigmented skin lesions as accurately as human experts is unclear. The aim of this study was to compare the diagnostic accuracy of state-of-the-art machine-learning algorithms with human readers for all clinically relevant types of benign and malignant pigmented skin lesions. METHODS: For this open, web-based, international, diagnostic study, human readers were asked to diagnose dermatoscopic images selected randomly in 30-image batches from a test set of 1511 images. The diagnoses from human readers were compared with those of 139 algorithms created by 77 machine-learning labs, who participated in the International Skin Imaging Collaboration 2018 challenge and received a training set of 10 015 images in advance. The ground truth of each lesion fell into one of seven predefined disease categories: intraepithelial carcinoma including actinic keratoses and Bowen's disease; basal cell carcinoma; benign keratinocytic lesions including solar lentigo, seborrheic keratosis and lichen planus-like keratosis; dermatofibroma; melanoma; melanocytic nevus; and vascular lesions. The two main outcomes were the differences in the number of correct specific diagnoses per batch between all human readers and the top three algorithms, and between human experts and the top three algorithms. FINDINGS: Between Aug 4, 2018, and Sept 30, 2018, 511 human readers from 63 countries had at least one attempt in the reader study. 283 (55·4%) of 511 human readers were board-certified dermatologists, 118 (23·1%) were dermatology residents, and 83 (16·2%) were general practitioners. When comparing all human readers with all machine-learning algorithms, the algorithms achieved a mean of 2·01 (95% CI 1·97 to 2·04; p<0·0001) more correct diagnoses (17·91 [SD 3·42] vs 19·92 [4·27]). 27 human experts with more than 10 years of experience achieved a mean of 18·78 (SD 3·15) correct answers, compared with 25·43 (1·95) correct answers for the top three machine algorithms (mean difference 6·65, 95% CI 6·06-7·25; p<0·0001). The difference between human experts and the top three algorithms was significantly lower for images in the test set that were collected from sources not included in the training set (human underperformance of 11·4%, 95% CI 9·9-12·9 vs 3·6%, 0·8-6·3; p<0·0001). INTERPRETATION: State-of-the-art machine-learning classifiers outperformed human experts in the diagnosis of pigmented skin lesions and should have a more important role in clinical practice. However, a possible limitation of these algorithms is their decreased performance for out-of-distribution images, which should be addressed in future research. FUNDING: None.

9.
Dermatol Pract Concept ; 9(2): 75-81, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31106008

RESUMO

Objectives: The aim of this review article is to summarize the effectiveness, potential adverse events, and indications of the main nonsurgical treatment alternatives for basal cell carcinoma. Methods: An extensive literature review was carried out. The most relevant articles were discussed and selected by the authors in order to provide a brief but evidence-based overview of the most common nonsurgical methods used for treating basal cell carcinoma. Results: Although surgery and Mohs micrographic surgery are often considered the optimal treatment options for basal cell carcinoma, these tumors can also be treated successfully with destructive techniques (eg, curettage alone, cryosurgery, or electrodesiccation), photodynamic therapy, topical drugs (eg, 5-fluorouracil, imiquimod, or ingenol mebutate), radiotherapy, or hedgehog pathway inhibitors. When choosing between these alternatives, physicians must take into consideration the tumor's size, location, and histopathological subtype. Special care should be taken when treating recurrent tumors. Furthermore, physician experience is of great importance when using destructive techniques. Finally, patient preference, potential adverse events, and cosmetic outcome should also be considered. Conclusions: Dermatologists and physicians treating basal cell carcinoma should have knowledge of and experience with the large arsenal of therapeutic alternatives available for the successful, safe, and individualized management of patients with basal cell carcinoma.

10.
Acta Derm Venereol ; 99(4): 468, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30924505
11.
JAMA Dermatol ; 155(1): 58-65, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30484822

RESUMO

Importance: Convolutional neural networks (CNNs) achieve expert-level accuracy in the diagnosis of pigmented melanocytic lesions. However, the most common types of skin cancer are nonpigmented and nonmelanocytic, and are more difficult to diagnose. Objective: To compare the accuracy of a CNN-based classifier with that of physicians with different levels of experience. Design, Setting, and Participants: A CNN-based classification model was trained on 7895 dermoscopic and 5829 close-up images of lesions excised at a primary skin cancer clinic between January 1, 2008, and July 13, 2017, for a combined evaluation of both imaging methods. The combined CNN (cCNN) was tested on a set of 2072 unknown cases and compared with results from 95 human raters who were medical personnel, including 62 board-certified dermatologists, with different experience in dermoscopy. Main Outcomes and Measures: The proportions of correct specific diagnoses and the accuracy to differentiate between benign and malignant lesions measured as an area under the receiver operating characteristic curve served as main outcome measures. Results: Among 95 human raters (51.6% female; mean age, 43.4 years; 95% CI, 41.0-45.7 years), the participants were divided into 3 groups (according to years of experience with dermoscopy): beginner raters (<3 years), intermediate raters (3-10 years), or expert raters (>10 years). The area under the receiver operating characteristic curve of the trained cCNN was higher than human ratings (0.742; 95% CI, 0.729-0.755 vs 0.695; 95% CI, 0.676-0.713; P < .001). The specificity was fixed at the mean level of human raters (51.3%), and therefore the sensitivity of the cCNN (80.5%; 95% CI, 79.0%-82.1%) was higher than that of human raters (77.6%; 95% CI, 74.7%-80.5%). The cCNN achieved a higher percentage of correct specific diagnoses compared with human raters (37.6%; 95% CI, 36.6%-38.4% vs 33.5%; 95% CI, 31.5%-35.6%; P = .001) but not compared with experts (37.3%; 95% CI, 35.7%-38.8% vs 40.0%; 95% CI, 37.0%-43.0%; P = .18). Conclusions and Relevance: Neural networks are able to classify dermoscopic and close-up images of nonpigmented lesions as accurately as human experts in an experimental setting.


Assuntos
Algoritmos , Dermoscopia/métodos , Redes Neurais de Computação , Neoplasias Cutâneas/patologia , Adulto , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Pele/patologia
12.
Dermatol Pract Concept ; 8(4): 330-336, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30479868

RESUMO

Background: Organ transplant recipients (OTRs) have a very high risk of developing cutaneous squamous cell carcinoma (cSCC). Immunosuppressed OTRs may have a higher proportion of poorly differentiated cSCC than non-OTRs. Objectives: The aim of this study was to investigate the degree of differentiation of cSCCs in OTRs compared with immunocompetent individuals. Patients/Methods: Data from the Swedish Cancer Registry were crosschecked with data from the Transplant registry of the Transplant Institute at Sahlgrenska University Hospital in Gothenburg, Sweden. All OTRs with a diagnosis of cSCC, basosquamous carcinoma, and/or cSCC in situ established at the Department of Dermatology, Sahlgrenska University Hospital, during 2002-2015 were included. The control group consisted of non-OTRs with the same diagnoses during the same time period. Results: During 2002-2015, 82 OTRs diagnosed with 515 tumors and 883 non-OTRs with 1,247 tumors were included. OTRs developed 0.47 tumors/year vs 0.10 tumors/year for non-OTRs, but no significant differences were observed in the degree of tumor differentiation of invasive cSCCs between OTRs and non-OTRs (P = 0.4). The distribution of poorly, moderately, and well-differentiated invasive cSCCs among OTRs and non-OTRs were 8.5% vs 12.5%, 22.1% vs 29.9%, and 69.4% vs 57.6%, respectively. Conclusions: OTRs do not develop a higher proportion of poorly differentiated cSCCs than non-OTRs.

13.
Acta Derm Venereol ; 98(9): 888-895, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-29972216

RESUMO

Methotrexate treatment has been linked with an increased risk of melanoma. However, a possible dose-response relationship with respect to methotrexate exposure and melanoma has not been addressed. The aim of the present study was to investigate whether higher accumulated doses of methotrexate correlate with an increased risk of melanoma, which would further support a possible association. A nationwide retrospective cohort study was conducted. All Swedish patients over 18 years of age who were dispensed methotrexate in the period 2005 to 2014 were registered (n = 101,966) and matched to the cancer registry. A Cox proportional hazards model, testing risk of melanoma vs. total accumulated methotrexate dose, controlled for sex, age group, and time from first to last dispensed prescription of methotrexate, yielded no significant risk dependence on dose, and a hazard ratio of 1.02 (95% CI 0.97-1.08). Overall, no conclusive dose-response relationship was observed between methotrexate exposure and risk of melanoma.


Assuntos
Imunossupressores/efeitos adversos , Melanoma/induzido quimicamente , Metotrexato/efeitos adversos , Neoplasias Cutâneas/induzido quimicamente , Adulto , Idoso , Relação Dose-Resposta a Droga , Feminino , Humanos , Incidência , Masculino , Melanoma/epidemiologia , Melanoma/patologia , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/patologia , Suécia/epidemiologia , Fatores de Tempo
14.
Photodermatol Photoimmunol Photomed ; 34(5): 338-342, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29753305

RESUMO

BACKGROUND: Photodynamic therapy (PDT) can be used to treat large fields of actinic keratoses (AKs) with high clearance rates. A notable downside is the amount of pain that accompany the treatment. This study aimed to optimize the illumination protocol during conventional PDT in order to reduce pain without compromising treatment effectiveness. METHODS: In this prospective, randomized study with a split-face design, patients with, symmetrically distributed AKs were included. All patients were treated using a ALA 78 mg/g gel. One side was illuminated with the Aktilite® CL-128 lamp and the other side with the RhodoLED® lamp in which the light intensity gradually increased to a maximum of 60%. Both sides received a total light dose of 37 J/cm2 . Pain during the treatment was measured using a visual analogue scale. The clinical effectiveness of the 2 treated sides was assessed after 12 weeks. RESULTS: Twenty-nine patients with 399 AKs were included. Illumination with the gradually increasing light intensity resulted in a decrease in the median visual analogue scale score by 1.1 points. Clearance rates were similar between the 2 lamps. CONCLUSION: Minimizing the light intensity during the illumination phase of PDT reduces pain, while still preserving a high clearance rate of AKs.


Assuntos
Ceratose Actínica/tratamento farmacológico , Medição da Dor , Dor/fisiopatologia , Fotoquimioterapia/métodos , Adulto , Feminino , Humanos , Ceratose Actínica/patologia , Ceratose Actínica/fisiopatologia , Masculino , Dor/etiologia , Fotoquimioterapia/efeitos adversos , Estudos Prospectivos
16.
Biointerphases ; 13(3): 03B402, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329503

RESUMO

A set of basal cell carcinoma samples, removed by Mohs micrographic surgery and pathologically identified as having an aggressive subtype, have been analyzed using time-of-flight secondary ion mass spectrometry (SIMS). The SIMS analysis employed a gas cluster ion beam (GCIB) to increase the sensitivity of the technique for the detection of intact lipid species. The GCIB also allowed these intact molecular signals to be maintained while surface contamination and delocalized chemicals were removed from the upper tissue surface. Distinct mass spectral signals were detected from different regions of the tissue (epidermis, dermis, hair follicles, sebaceous glands, scar tissue, and cancerous tissue) allowing mass spectral pathology to be performed. The cancerous regions of the tissue showed a particular increase in sphingomyelin signals that were detected in both positive and negative ion mode along with increased specific phosphatidylserine and phosphatidylinositol signals observed in negative ion mode. Samples containing mixed more and less aggressive tumor regions showed increased phosphatidylcholine lipid content in the less aggressive areas similar to a punch biopsy sample of a nonaggressive nodular lesion.


Assuntos
Carcinoma Basocelular/patologia , Espectrometria de Massa de Íon Secundário/métodos , Biópsia , Humanos , Microcirurgia , Fosfolipídeos/análise , Pele/patologia
17.
Eur J Dermatol ; 27(6): 615-619, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29171392

RESUMO

Fitzpatrick skin phototype classification is widely used to assess risk factors for skin cancers. This skin type evaluation is easy to use in clinical practice but is not always applied as initially described, nor practiced in a standardised way. This can have implications on the results of relevant dermato-epidemiological studies. To demonstrate, in a large multinational setting, that the phrasing of questions on sun sensitivity can have a strong impact on the perception and reporting of skin phototype, as well as the importance of a standardised procedure for phototype assessment. Using data collected from 48,258 screenees of the Euromelanoma campaign in six European countries from 2009 to 2011, we analysed the impact of change in the question phrasing on phototype classification in each country. Changing the wording of a question to assess the phototype of a person also significantly influenced the classification of phototypes in different countries (p<0.001 for each country). The difference essentially corresponded to a shift towards a less sun-sensitive skin type when a shorter question that did not include skin colour description was used. The only exception was Portugal where phototype was not patient-assessed and classification shifted towards a more sun-sensitive phototype. Results were statistically significant and highly consistent, irrespective of gender. The phrasing of questions on skin type is important and substantially influences reporting. A standardized procedure to classify phototypes should be used in order to obtain comparable data between studies.


Assuntos
Pigmentação da Pele , Pele/efeitos da radiação , Queimadura Solar/classificação , Luz Solar , Europa (Continente) , Humanos , Idioma , Anamnese/métodos , Neoplasias Cutâneas , Queimadura Solar/patologia , Fatores de Tempo
18.
J Am Acad Dermatol ; 77(6): 1100-1109, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28941871

RESUMO

BACKGROUND: Nonpigmented skin cancer is common, and diagnosis with the unaided eye is error prone. OBJECTIVE: To investigate whether dermatoscopy improves the diagnostic accuracy for nonpigmented (amelanotic) cutaneous neoplasms. METHODS: We collected a sample of 2072 benign and malignant neoplastic lesions and inflammatory conditions and presented close-up images taken with and without dermatoscopy to 95 examiners with different levels of experience. RESULTS: The area under the curve was significantly higher with than without dermatoscopy (0.68 vs 0.64, P < .001). Among 51 possible diagnoses, the correct diagnosis was selected in 33.1% of cases with and 26.4% of cases without dermatoscopy (P < .001). For experts, the frequencies of correct specific diagnoses of a malignant lesion improved from 40.2% without to 51.3% with dermatoscopy. For all malignant neoplasms combined, the frequencies of appropriate management strategies increased from 78.1% without to 82.5% with dermatoscopy. LIMITATIONS: The study deviated from a real-life clinical setting and was potentially affected by verification and selection bias. CONCLUSIONS: Dermatoscopy improves the diagnosis and management of nonpigmented skin cancer and should be used as an adjunct to examination with the unaided eye.


Assuntos
Dermoscopia , Neoplasias Cutâneas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
19.
Acta Derm Venereol ; 97(10): 1206-1211, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28761961

RESUMO

The incidence rates of thin melanomas (≤1 mm Breslow thickness) have increased in many fair-skinned populations, prompting a need to better identify patients with thin melanomas who will eventually die from the disease. This study aimed to describe the clinicopathological characteristics of lethal melanomas in Western Sweden, with a focus on thin lesions. Population-based data on invasive melanomas diagnosed during the years 1990 to 2014 were extracted from the Swedish Melanoma Registry, and linked to the Swedish Cause of Death Registry. The age-standardized incidence (US population 2000) of thin melanomas increased from 9.1×10-5 (95% confidence interval (95% CI) 8.5-9.8) to 21.3×10-5 (95% CI 20.4-22.1) during the study period. Thin melanomas comprised 55.2% of the total and contributed to 13.5% of all melanoma deaths. Non-ulcerated melanomas 0.76-1 mm and ulcerated melanomas 0.26-1.0 mm showed a poorer survival compared with other thin melanomas.


Assuntos
Melanoma/mortalidade , Neoplasias Cutâneas/mortalidade , Adulto , Distribuição por Idade , Idoso , Feminino , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Melanoma/patologia , Melanoma/terapia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Sistema de Registros , Fatores de Risco , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Suécia/epidemiologia , Fatores de Tempo
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