Michael A. Marchetti

Validity and Reliability of Dermoscopic Criteria Used to Differentiate Nevi From Melanoma: A Web-Based International Dermoscopy Society Study

IMPORTANCE The comparative diagnostic performance of dermoscopic algorithms and their individual criteria are not well studied. OBJECTIVES To analyze the discriminatory power and reliability of dermoscopic criteria used in melanoma detection and compare the diagnostic accuracy of existing algorithms. DESIGN, SETTING, AND PARTICIPANTS This was a retrospective, observational study of 477 lesions (119 melanomas [24.9%] and 358 nevi [75.1%]), which were divided into 12 image sets that consisted of 39 or 40 images per set. A link on the International Dermoscopy Society website from January 1, 2011, through December 31, 2011, directed participants to the study website. Data analysis was performed from June 1, 2013, through May 31, 2015. Participants included physicians, residents, and medical students, and there were no specialty-type or experience-level restrictions. Participants were randomly assigned to evaluate 1 of the 12 image sets. MAIN OUTCOMES AND MEASURES Associations with melanoma and intraclass correlation coefficients (ICCs) were evaluated for the presence of dermoscopic criteria. Diagnostic accuracy measures were estimated for the following algorithms: the ABCD rule, the Menzies method, the 7-point checklist, the 3-point checklist, chaos and clues, and CASH (color, architecture, symmetry, and homogeneity). RESULTS A total of 240 participants registered, and 103 (42.9%) evaluated all images. The 110 participants (45.8%) who evaluated fewer than 20 lesions were excluded, resulting in data from 130 participants (54.2%), 121 (93.1%) of whom were regular dermoscopy users. Criteria associated with melanoma included marked architectural disorder (odds ratio [OR], 6.6; 95% CI, 5.6-7.8), pattern asymmetry (OR, 4.9; 95% CI, 4.1-5.8), nonorganized pattern (OR, 3.3; 95% CI, 2.9-3.7), border score of 6 (OR, 3.3; 95% CI, 2.5-4.3), and contour asymmetry (OR, 3.2; 95% CI, 2.7-3.7) (P < .001 for all). Most dermoscopic criteria had poor to fair interobserver agreement. Criteria that reached moderate levels of agreement included comma vessels (ICC, 0.44; 95% CI, 0.40-0.49), absence of vessels (ICC, 0.46; 95% CI, 0.42-0.51), dark brown color (ICC, 0.40; 95% CI, 0.35-0.44), and architectural disorder (ICC, 0.43; 95% CI, 0.39-0.48). The Menzies method had the highest sensitivity for melanoma diagnosis (95.1%) but the lowest specificity (24.8%) compared with any other method (P < .001). The ABCD rule had the highest specificity (59.4%). All methods had similar areas under the receiver operating characteristic curves. CONCLUSIONS AND RELEVANCE Important dermoscopic criteria for melanoma recognition were revalidated by participants with varied experience. Six algorithms tested had similar but modest levels of diagnostic accuracy, and the interobserver agreement of most individual criteria was poor.

Technology and Technique Standards for Camera-Acquired Digital Dermatologic Images: A Systematic Review

IMPORTANCE Photographs are invaluable dermatologic diagnostic, management, research, teaching, and documentation tools. Digital Imaging and Communications in Medicine (DICOM) standards exist for many types of digital medical images, but there are no DICOM standards for camera-acquired dermatologic images to date. OBJECTIVE To identify and describe existing or proposed technology and technique standards for camera-acquired dermatologic images in the scientific literature. EVIDENCE REVIEW Systematic searches of the PubMed, EMBASE, and Cochrane databases were performed in January 2013 using photography and digital imaging, standardization, and medical specialty and medical illustration search terms and augmented by a gray literature search of 14 websites using Google. Two reviewers independently screened titles of 7371 unique publications, followed by 3 sequential full-text reviews, leading to the selection of 49 publications with the most recent (1985-2013) or detailed description of technology or technique standards related to the acquisition or use of images of skin disease (or related conditions). FINDINGS No universally accepted existing technology or technique standards for camera-based digital images in dermatology were identified. Recommendations are summarized for technology imaging standards, including spatial resolution, color resolution, reproduction (magnification) ratios, postacquisition image processing, color calibration, compression, output, archiving and storage, and security during storage and transmission. Recommendations are also summarized for technique imaging standards, including environmental conditions (lighting, background, and camera position), patient pose and standard view sets, and patient consent, privacy, and confidentiality. Proposed standards for specific-use cases in total body photography, teledermatology, and dermoscopy are described. CONCLUSIONS AND RELEVANCE The literature is replete with descriptions of obtaining photographs of skin disease, but universal imaging standards have not been developed, validated, and adopted to date. Dermatologic imaging is evolving without defined standards for camera-acquired images, leading to variable image quality and limited exchangeability. The development and adoption of universal technology and technique standards may first emerge in scenarios when image use is most associated with a defined clinical benefit.

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.

Genetic factors associated with naevus count and dermoscopic patterns: preliminary results from the Study of Nevi in Children (SONIC).

Melanocytic naevi are an important risk factor for melanoma. Naevi with distinct dermoscopic patterns can differ in size, distribution and host pigmentation characteristics.

Biopsies of Nevi in Children and Adolescents in the United States, 2009 Through 2013

Biopsies of Nevi in Children and Adolescents in the United States, 2009 Through 2013 The increase in incidence and mortality of melanoma over the past 30 years has heightened public and physician awareness. It is suggested that the combination of increasing detection pressure and poor specificity of current diagnostic strategies is driving biopsy rates to alarming levels in younger individuals despite a low risk of melanoma.1 Nevertheless, the number of nevi biopsied in children and adolescents remains poorly characterized in the United States.

Dermatoscopic imaging of skin lesions by high school students: a cross-sectional pilot study

Background: The ability of novices to perform imaging of skin lesions is not well studied. Objectives: To determine the ability of 12th grade high school students without formal training to take clinical and dermatoscopic images of skin lesions on patient-actors. Patients/Methods: Nineteen participants were divided into 11 gender-specific groups of 1–2 students. Groups were provided written instructions and assessed in their ability to (a) identify 8 pre-specified skin lesions, (b) take overview clinical images, and (c) take contact, polarized dermatoscopic images. Groups captured the same images twice using two different cameras [Nikon TM 1 J1 / VEOS HD1 and a VEOS DS3 (Canfield Scientific, Inc.)]. The sequence of camera use was determined using block randomization. If students made visibly poor skin contact during dermatoscopic imaging using their first camera, study investigators provided verbal instructions to place the second camera directly onto the skin. Students completed anonymous surveys before and after the imaging activity. Results: Students were proficient at identifying the correct pre-specified skin lesions (86/88, 98%), capturing sufficient quality overview clinical images of the back and legs (41/42, 98%), and taking dermatoscopic images of the entire skin lesion (174/176, 99%). Regarding dermatoscopic image quality, 116 of 175 (66%) images were in focus. Out of focus images were attributed to poor skin contact. Groups that received feedback (n=4) were able to obtain a significantly higher proportion of in focus dermatoscopic images using their second camera compared to their first camera (16% to 72%, P<0.001). Conclusions: We identified several barriers that exist for participant-acquired dermatoscopic imaging. Instructions emphasizing the importance of skin contact are useful. Our results may help guide future patient-acquired teledermatoscopy efforts.

Cutaneous manifestations of human T-cell lymphotrophic virus type-1-associated adult T-cell leukemia/lymphoma: A single-center, retrospective study

BACKGROUND Limited data exist regarding cutaneous involvement of adult T-cell leukemia/lymphoma (ATLL), particularly in the United States. OBJECTIVE We sought to characterize clinical and histopathologic features of ATLL in patients with skin involvement. METHODS We retrospectively identified patients with ATLL from a single institution given a diagnosis during a 15-year period (1998-2013). Patients were categorized by the Shimoyama classification and stratified into skin-first, skin-second, and skin-uninvolved courses. RESULTS The study population included 17 skin-first, 8 skin-second, and 29 skin-uninvolved cases. Skin-first patients (6 acute, 1 lymphoma, 4 chronic, 6 smoldering) were overwhelmingly of Caribbean origin (94%). They had longer median symptom duration (11.9 vs 1.9 months, P < .001) and overall survival (26.7 vs 10.0 months, P < .001) compared with skin-second/skin-uninvolved patients. Cutaneous lesion morphology at diagnosis included nodulotumoral (35%), multipapular (24%), plaques (24%), patches (12%), and erythroderma (6%). After initial skin biopsy, 14 of 17 received a non-ATLL diagnosis, most commonly mycosis fungoides (47%). Notable histopathologic findings from 43 biopsy specimens included greater than or equal to 20:1 CD4:CD8 ratio (79%), angiocentrism (78%), CD25(+) (71%), large cell morphology (70%), CD30(+) (68%), epidermal infiltration of atypical lymphocytes (67%) forming large Pautrier-like microabscesses (55%), and folliculotropism (65%). LIMITATIONS This was a retrospective, single-center, tertiary referral center study with small sample size. CONCLUSION Skin-first patients with ATLL in the United States are diagnostically challenging. Familiarity with clinicopathologic features may aid in diagnosis.

Melanocytic naevi with globular and reticular dermoscopic patterns display distinct BRAF V600E expression profiles and histopathological patterns

BRAF (v‐raf murine sarcoma viral oncogene homologue B) V600E mutations have been detected with high frequency in melanocytic naevi. Few studies have stratified analyses by naevus dermoscopic pattern.

Cross‐sectional analysis of the dermoscopic patterns and structures of melanocytic naevi on the back and legs of adolescents

Junctional (flat) naevi predominate on the extremities, whereas dermal (raised) naevi are found primarily on the head, neck and trunk. Few studies have investigated the anatomical site prevalence of melanocytic naevi categorized using dermoscopy.

Growth-Curve Modeling of Nevi With a Peripheral Globular Pattern.

Importance Although nevi with a peripheral rim of globules (peripheral globular nevi [PGN]) observed with dermoscopy are associated with enlarging melanocytic nevi, their actual growth dynamics remain unknown. Because change is a sensitive but nonspecific marker for melanoma, beginning to understand the growth patterns of nevi may improve the ability of physicians to differentiate normal from abnormal growth and reduce unnecessary biopsies. Objective To study the growth dynamics and morphologic evolution of PGN on dermoscopy. Design, Setting, and Participants A total of 84 participants with 121 PGN from September 1, 1999, through May 1, 2013, were identified retrospectively. Cohorts were recruited from the Memorial Sloan Kettering Cancer Center; Melanoma Unit of the Hospital Clinic, University of Barcelona; and Study of Nevi in Children. All 3 cohorts underwent longitudinal monitoring with serial dermoscopic imaging of their PGN. Data analysis was performed from May 1, 2014, through April 1, 2015. Main Outcomes and Measures Establishment of the natural growth curve of PGN. The secondary aim was to establish the median time to growth cessation in those PGN for which the size eventually stabilized and/or had begun to decrease during the study period. Results The median duration of follow-up was 25.1 (range, 2.0-114.4) months. Most of the nevi (116 [95.9%]) enlarged at some point during sequential monitoring. The rate of increase in the surface area of PGN varied among cohorts and ranged from -0.47 to 2.26 mm2/mo (mean rate, 0.25 [95% CI, 0.14-0.36] mm2/mo). The median time to growth cessation in the 26 PGN that stabilized or decreased in size (21.5%) was 58.6 months. All lesions changed in a symmetric manner and 91 (75.2%) displayed a decrease in the density of peripheral globules over time. Conclusions and Relevance Nevi displaying a peripheral globular pattern enlarged symmetrically with apparent growth cessation occurring during a span of 4 to 5 years. Our results reiterate the important concept that not all growth is associated with malignancy.