3D Whole-body skin imaging for automated melanoma detection.

BACKGROUND: Existing artificial intelligence for melanoma detection has relied on analysing images of lesions of clinical interest, which may lead to missed melanomas. Tools analysing the entire skin surface are lacking. OBJECTIVES: To determine if melanoma can be distinguished from other skin lesions using data from automated analysis of 3D-images. METHODS: Single-centre, retrospective, observational convenience sample of patients diagnosed with melanoma at a tertiary care cancer hospital. Eligible participants were those with a whole-body 3D-image captured within 90 days prior to the diagnostic skin biopsy. 3D-images were obtained as standard of care using VECTRA WB360 Whole Body 3-dimensional Imaging System (Canfield Scientific). Automated data from image processing (i.e. lesion size, colour, border) for all eligible participants were exported from VECTRA DermaGraphix research software for analysis. The main outcome was the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 35 patients contributed 23,538 automatically identified skin lesions >2 mm in largest diameter (102-3021 lesions per participant). All were White patients and 23 (66%) were males. The median (range) age was 64 years (26-89). There were 49 lesions of melanoma and 22,489 lesions that were not melanoma. The AUC for the prediction model was 0.94 (95% CI: 0.92-0.96). Considering all lesions in a patient-level analysis, 14 (28%) melanoma lesions had the highest predicted score or were in the 99th percentile among all lesions for an individual patient. CONCLUSIONS: In this proof-of-concept pilot study, we demonstrated that automated analysis of whole-body 3D-images using simple image processing techniques can discriminate melanoma from other skin lesions with high accuracy. Further studies with larger, higher quality, and more representative 3D-imaging datasets would be needed to improve and validate these results.

The long-term evolution of melanocytic nevi among high-risk adults.

BACKGROUND: There is little understanding regarding the long-term natural history of melanocytic nevi among adults. OBJECTIVE: The objective of the study was to describe the long-term natural history of individual nevi located on the torso of high-risk patients. METHODS: All patients attending Memorial Sloan Kettering Cancer Center (MSKCC) who underwent two total body photography (TBP) sessions 15+ years apart were included ('retrospective' group). To account for a potential selection bias, we also included consecutive patients who had TBP 15+ years ago and consented to undergo follow-up TBP ('prospective' group). We compared baseline and follow-up torso images on the TBPs and evaluated the number of total, new and disappearing nevi; number of seborrheic keratoses and actinic keratoses; each nevus' diameter at both time points; each nevus' colour change; the presence of clinical atypia; and when dermoscopy was available, the dermoscopic features at each time point. RESULTS: One hundred six patients were included in the study. Although the average age of the patients was 40 at baseline TBP, most patients developed new nevi between imaging sessions (median 16.4 years) with an average of 2.6 (SD = 4.8) nevi per participant. The average number of disappearing nevi was 0.3 (SD = 0.6). In addition, 62/106 (58%) patients had an absolute increase, and 9/106 (8%) patients had an absolute decrease in their total nevus count. Roughly half (49%: 1416/2890) of the nevi that could be evaluated at both time points increased in diameter by at least 25%. Only 6% (159/2890) of nevi shrunk in diameter by at least 25%. Patients with a history of melanoma had a higher rate of disappearing nevi, and their nevi were more likely to grow. Most nevi demonstrated no significant dermoscopic changes. CONCLUSIONS: High-risk patients acquire new nevi throughout life with very few nevi disappearing over time. Contrary to prior reports, most nevi in adults increase in diameter, while few nevi shrink.

Skin cancer risk among testicular germ-cell cancer survivors: a systematic review and meta-analysis.

Testicular germ-cell tumours (TGCT) are the most common cancer among young adult men. Previous studies suggested TGCT survivors have an increased risk for skin cancer. The goal of this study was to systematically review the literature and evidence regarding skin cancer risk among TGCT survivors compared with the general population. PubMed, EMBASE, Web of Science, Cochrane Databases and reference lists were included in the search. A systematic review of all comparative studies with more than 10 TGCT survivors reporting on skin cancer incidence was performed. A meta-analysis of the Standardized Incidence Rate (SIR) was calculated by pooling study-specific log-transformed estimates using the random-effects model. Risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. Nineteen studies that reported on 147 935 TGCT survivors were included. Pooled SIR for skin cancer and for melanoma incidence among TGCT survivors were 1.93 (95% CI 1.62-2.29, P < 0.0001) and 1.81 (95% CI 1.57-2.08, P < 0.0001), respectively. In conclusion, compared to the general population, TGCT survivors have an increased risk for developing skin cancer and melanoma. Additional long-term studies that include TGCT survivors, additional risk factors and all subtypes of skin cancer are required.

Human surface anatomy terminology for dermatology: a Delphi consensus from the International Skin Imaging Collaboration.

BACKGROUND: There is no internationally vetted set of anatomic terms to describe human surface anatomy. OBJECTIVE: To establish expert consensus on a standardized set of terms that describe clinically relevant human surface anatomy. METHODS: We conducted a Delphi consensus on surface anatomy terminology between July 2017 and July 2019. The initial survey included 385 anatomic terms, organized in seven levels of hierarchy. If agreement exceeded the 75% established threshold, the term was considered 'accepted' and included in the final list. Terms added by the participants were passed on to the next round of consensus. Terms with <75% agreement were included in subsequent surveys along with alternative terms proposed by participants until agreement was reached on all terms. RESULTS: The Delphi included 21 participants. We found consensus (≥75% agreement) on 361/385 (93.8%) terms and eliminated one term in the first round. Of 49 new terms suggested by participants, 45 were added via consensus. To adjust for a recently published International Classification of Diseases-Surface Topography list of terms, a third survey including 111 discrepant terms was sent to participants. Finally, a total of 513 terms reached agreement via the Delphi method. CONCLUSIONS: We have established a set of 513 clinically relevant terms for denoting human surface anatomy, towards the use of standardized terminology in dermatologic documentation.

Accuracy of tele-consultation on management decisions of lesions suspect for melanoma using reflectance confocal microscopy as a stand-alone diagnostic tool.

BACKGROUND: Diagnostic accuracy of reflectance confocal microscopy (RCM) as a stand-alone diagnostic tool for suspect skin lesions has not been extensively studied. OBJECTIVE: Primary aim was to measure experts' accuracy in RCM-based management decisions. Secondary aim was to identify melanoma-specific RCM features. METHODS: The study enrolled patients ≥18 years that underwent biopsy of skin lesions clinically suspected to be melanoma. One hundred lesions imaged by RCM were randomly selected from 439 lesions prospectively collected at four pigmented lesion clinics. The study data set included 23 melanomas, three basal cell and two squamous cell carcinomas, 11 indeterminate melanocytic lesions and 61 benign lesions including 50 nevi. Three expert RCM evaluators were blinded to clinical or dermoscopic images, and to the final histopathological diagnosis. Evaluators independently issued a binary RCM-based management decision, 'biopsy' vs. 'observation'; these decisions were scored against histopathological diagnosis, with 'biopsy' as the correct management decision for malignant and indeterminate lesions. A subset analysis of 23 melanomas and 50 nevi with unequivocal histopathological diagnosis was performed to identify melanoma-specific RCM features. RESULTS: Sensitivity, specificity and diagnostic accuracy were 74%, 67% and 70% for reader 1, 46%, 84% and 69% for reader 2, and 72%, 46% and 56% for reader 3, respectively. The overall kappa for management decisions was 0.34. Readers had unanimous agreement on management for 50 of the 100 lesions. Non-specific architecture, non-visible papillae, streaming of nuclei, coarse collagen fibres and abnormal vasculature showed a significant association with melanoma in the evaluation of at least two readers. CONCLUSIONS: Reflectance confocal microscopy tele-consultation of especially challenging lesions, based on image review without benefit of clinical or dermoscopy images, may be associated with limited diagnostic accuracy and interobserver agreement. Architectural and stromal criteria may emerge as potentially useful and reproducible criteria for melanoma diagnosis.

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

BACKGROUND: 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. OBJECTIVES: To identify the prevalence of dermoscopic patterns and structures of naevi from the back and legs of adolescents. METHODS: Dermoscopic images of acquired melanocytic naevi were obtained from the back and legs of students from a population-based cohort in Framingham, Massachusetts. Naevi were classified into reticular, globular, homogeneous or complex dermoscopic patterns. Multinomial logistic regression modelling assessed the associations between dermoscopic pattern and anatomical location. RESULTS: In total 509 participants (mean age 14 years) contributed 2320 back naevi and 637 leg naevi. Compared with homogeneous naevi, globular and complex naevi were more commonly observed on the back than the legs [odds ratio (OR) 29·39, 95% confidence interval (CI) 9·53-90·65, P < 0·001 and OR 6·8, 95% CI 2·7-17·14, P < 0·001, respectively], whereas reticular lesions were less likely to be observed on the back than on the legs (OR 0·67, 95% CI 0·54-0·84, P = 0·001). Naevi containing any globules were more prevalent on the back than on the legs (25% vs. 3·6%, P < 0·001). Naevi containing any network were more prevalent on the legs than on the back (56% vs. 40·6%, P < 0·001). CONCLUSIONS: These findings add to a robust body of literature suggesting that dermoscopically defined globular and reticular naevi represent biologically distinct naevus subsets that differ in histopathological growth pattern, age- and anatomical-site-related prevalence, molecular phenotype and aetiological pathways.

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

BACKGROUND: Melanocytic naevi are an important risk factor for melanoma. Naevi with distinct dermoscopic patterns can differ in size, distribution and host pigmentation characteristics. OBJECTIVES: We examined MC1R and 85 other candidate loci in a cohort of children to test the hypothesis that the development and dermoscopic type of naevi are modulated by genetic variants. METHODS: Buccal DNAs were obtained from a cohort of 353 fifth graders (mean age 10·4 years). Polymorphisms were chosen based on a known or anticipated role in naevi and melanoma. Associations between single-nucleotide polymorphisms (SNPs) and baseline naevus count were determined by multivariate regression adjusting for sex, race/ethnicity and sun sensitivity. Dermoscopic images were available for 853 naevi from 290 children. Associations between SNPs and dermoscopic patterns were determined by polytomous regression. RESULTS: Four SNPs were significantly associated with increasing (IRF4) or decreasing (PARP1, CDK6 and PLA2G6) naevus count in multivariate shrinkage analyses with all SNPs included in the model; IRF4 rs12203952 showed the strongest association with log naevus count (relative risk 1·56, P < 0·001). Using homogeneous naevi as the reference, IRF4 rs12203952 and four other SNPs in TERT, CDKN1B, MTAP and PARP1 were associated with either globular or reticular dermoscopic patterns (P < 0·05). CONCLUSIONS: Our results provide evidence that subsets of naevi defined by dermoscopic patterns differ in their associations with germline genotypes and support the hypothesis that dermoscopically defined subsets of naevi are biologically distinct. These results require confirmation in larger cohorts. If confirmed, these findings will improve the current knowledge of naevogenesis and assist in the identification of individuals with high-risk phenotypes.

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

BACKGROUND: 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. OBJECTIVES: To determine the frequency of BRAF V600E expression and histopathological pattern in acquired melanocytic naevi distinguished by a globular vs. reticular dermoscopic pattern. METHODS: We retrospectively identified histologically proven melanocytic naevi with banal reticular or globular dermoscopic patterns and evaluated BRAF V600E expression using immunohistochemistry. RESULTS: BRAF V600E expression was detected in 11 of 12 globular naevi vs. four of 13 reticular naevi (91·7% vs. 30·1%, P = 0·004). A predominantly dermal growth pattern (P < 0·001) and the presence of large junctional nests (P = 0·017) were each associated with a globular dermoscopic pattern. The presence of either a predominantly dermal growth pattern or large junctional nests was found in 13 of 15 naevi positive for BRAF V600E and in two of 10 naevi negative for BRAF V600E (86·7% vs. 20%, P = 0·002). CONCLUSIONS: The frequency of BRAF V600E mutations differs in naevi distinguished by unique dermoscopic structures and microanatomical growth patterns. Globular naevi, which most often histologically correspond to a predominantly dermal growth pattern and/or the presence of large junctional nests, are significantly more likely to express BRAF V600E than reticular naevi. These preliminary results require validation, but may directly inform future studies of naevogenesis and melanoma genesis.

Clinical and dermoscopic characteristics of new naevi in adults: results from a cohort study.

BACKGROUND: Naevogenesis is a process known to occur throughout life. To date, investigators have made conclusions about new naevi in adults based on results of cross-sectional studies. OBJECTIVES: To determine the incidence of new naevus development in adults and to describe the dermoscopic morphology of new naevi. METHODS: A cohort of 182 patients seen at the outpatient dermatology clinic at Memorial Sloan-Kettering Cancer Center between 2000 and 2009 was evaluated with baseline total body photographs. The patients were aged 17 years or older and had presented for routine follow-up surveillance examination at least 3 months after baseline total body photographs. The number of new naevi and the dermoscopic morphology of these naevi were recorded. RESULTS: Of the 182 patients evaluated, 50 (27%) developed at least one new naevus during follow-up. The incidence of new naevi was 202 per 1000 person-years of follow-up. The most common types of naevi were reticular (47·1%), followed by the homogeneous (22·1%) and complex (reticuloglobular) patterns (15·4%). CONCLUSIONS: Our results provide support for the theory that there are two distinct pathways of naevogenesis, a dynamic process occurring throughout life. This study demonstrates that the predominant dermoscopic morphology of newly acquired naevi in adults is reticular.

One-year follow-up of dermoscopy education on the ability of medical students to detect skin cancer.

BACKGROUND: Learning skin cancer detection skills is important, yet many medical schools lack a standardized skin cancer examination (SCE) curriculum. OBJECTIVE: To determine medical students' skills in discriminating benign from malignant skin lesions on a 10-item image-based test one year after receiving a SCE intervention. METHODS: Cohort 1 received SCE teaching only. Cohort 2 received SCE teaching with dermoscopy tutorial, and a dermatoscope. The same test was given to assess students post-intervention and one year later. RESULTS: 43% (n = 145) and 38% (n = 143) of cohorts 1 and 2, respectively, participated one year later. Both cohorts improved or maintained their scores to correctly classify all lesions from post-intervention to one-year follow-up. After one year, cohort 2 maintained higher scores for successful identification of both benign and malignant lesions as compared to cohort 1. CONCLUSION: Medical students receiving a SCE intervention can improve their diagnostic skills after one year, especially with the aid of dermoscopy.

Dermoscopic patterns and subclinical melanocytic nests in normal-appearing skin.

BACKGROUND: Dermoscopic patterns of normal-appearing skin have received little scrutiny. We have recently completed an analysis of dermoscopic patterns of naevi in children. OBJECTIVES: To describe dermoscopic patterns in the normal-appearing skin surrounding naevi and to explore histological features of patterned background skin. METHODS: Dermoscopic images of back naevi were obtained from a population-based sample of fifth grade students. The dermoscopic pattern of the background skin around the naevi was analysed. We examined histopathological features of background skin patterns in a convenience sample of seven specimens from six adult patients. RESULTS: We observed a dermoscopic pattern in the background of normal-appearing skin in 41% of 1192 dermoscopic images from the backs of the 443 children. The background skin pattern was less frequent in individuals with a fair skin (P < 0.001). A globular pattern was observed in 201 images (17%) and a reticular pattern was seen in 287 images (24%), of which 112 images also showed globules. Inter-rater reliability between the two observers for a random sample of 100 images was excellent (kappa = 0.77). In four specimens with a globular background pattern, microscopic melanocytic nests were observed in the normal-appearing skin. No subclinical naevus nests were observed in three reticular pattern specimens. CONCLUSIONS: Dermoscopically recognized patterns are commonly present in clinically normal skin of children. Microscopic melanocytic nests may be observed in normal-appearing skin with a globular skin pattern.

Confocal mosaicing microscopy in skin excisions: a demonstration of rapid surgical pathology.

Precise micro-surgical removal of tumour with minimal damage to the surrounding normal tissue requires a series of excisions, each guided by an examination of frozen histology of the previous. An example is Mohs surgery for the removal of basal cell carcinomas (BCCs) in skin. The preparation of frozen histology is labour-intensive and slow. Confocal microscopy may enable rapid detection of tumours directly in surgical excisions with minimal need for frozen histology. Mosaicing of images enables observation of nuclear and cellular morphology in large areas of surgically excised tissue. In skin, the use of 10-1% acetic acid as a reflectance contrast agent brightens nuclei in 0.5-5 min and enhances nuclear-to-dermis contrast and detectability of BCCs. A tissue fixture was engineered for precisely mounting surgical excisions to enable mosaicing of 36 x 36 images to create a field of view of 12 x 12 mm. This large field of view displays the excision at 2x magnification, similar to that routinely used by Mohs surgeons when examining frozen histology. Comparison of mosaics to histology demonstrates detectability of BCCs. Confocal mosaicing presently requires 9 min, instead of 20-45 min per excision for preparing frozen histology, and thus may provide a means for rapid pathology-at-the-bedside to expedite and guide surgery.

Dermoscopic patterns of naevi in fifth grade children of the Framingham school system.

BACKGROUND: Childhood is a critical period for naevogenesis. OBJECTIVE: To describe the prevalence of dermoscopic patterns of naevi using cross-sectional data from a population-based cohort of children. METHODS: We obtained overview digital photography of the back of fifth graders (age 10-11 years) from all 10 schools in Framingham, MA, U.S.A. From each participant, dermoscopic images of up to four naevi were obtained, including the largest and one randomly selected naevus on the upper back and a corresponding pair from the lower back. RESULTS: The study included 443 children, 61% boys, with 1181 back naevi analysed. Globular pattern was seen in 37% of naevi, reticular pattern in 13%, homogeneous pattern in 44% and complex (reticular-globular) dermoscopic pattern in 5%. Globular naevi were significantly more frequent and larger on the upper than the lower back. There was a significant hierarchic trend in naevus diameter by dermoscopic pattern: complex naevi (4.3 mm)>globular (3.3 mm)>reticular (3.0 mm)>homogeneous (2.8 mm). Reticular naevi were more prevalent in children with darker pigment phenotype (P<0.0001). There was a decrease in the size of naevi in children with darker pigmentation (P<0.0001). CONCLUSIONS: An interrelationship was observed in childhood between dermoscopic pattern, naevus size, anatomical location on the back and pigment phenotype.

Complex dermoscopic pattern: a potential risk marker for melanoma.

BACKGROUND: Dysplastic naevi have repeatedly been shown to be an independent risk factor for melanoma; however, risk estimates vary. Dermoscopy has allowed for more elaborate classification of naevi based on global patterns. OBJECTIVES: To assess dermoscopic images of naevi from patients with melanoma and controls to explore dermoscopic patterns that are associated with melanoma risk. METHODS: Dermoscopic images of naevi from the backs of 20 patients with melanoma and 20 age- and sex-matched controls were reviewed for dermoscopic patterns and structures. An unblinded review of 187 naevi of patients and 150 naevi of controls was completed. Complex global dermoscopic pattern was defined in naevi presenting both network and globules, with or without structureless areas. RESULTS: Complex global dermoscopic pattern was observed more frequently in melanoma patients than controls (odds ratio, OR 2.9, P = 0.003). As for specific dermoscopic structures, presence of globules was observed more frequently in patients than controls (OR 2.3, P = 0.0001), whereas presence of dots was inversely associated with case status (OR 0.5, P = 0.002). CONCLUSIONS: These pilot data suggest that dermoscopic pattern may serve as a more robust and specific marker of melanoma risk than clinical naevus phenotype.

Clinical and dermoscopic changes in common melanocytic nevi in school children: the Framingham school nevus study.

BACKGROUND: Nevi are potential precursors of malignant melanoma and are important risk factors for the development of the disease. Childhood may be a critical time for the formation and evolution of nevi. OBJECTIVES: To document the development of new nevi and to document the clinical and dermoscopic changes in index nevi in school children during a 1-year follow-up. METHODS: Digital photographs and dermoscopic images of the back of subjects were compared at baseline and 1-year follow-up to assess changes in nevi counts and in clinical and dermoscopic features of index nevi. RESULTS: Overall participation rate was 81% (42/52). 56.4% of study participants were found to have an increased number of nevi at 1-year follow-up. All nevi were small and clinically insignificant. Fifty percent of study participants were found to have dermoscopic changes in their index nevi at 1-year follow-up. Eighty-five percent of these changes were classified as subtle and 15.0% as obvious. CONCLUSIONS: A significant portion of students developed new nevi over the course of 1 year. Most index nevi remained stable in pattern and structure. Benign dermoscopic changes occurred in 50.0% of index nevi. However, none of the dermoscopically changed nevi revealed any major changes and the overall nevus pattern remained unchanged. The relevance of these changes is uncertain and further follow-up may elucidate their significance.

Utility of the Wood's light: five cases from a pigmented lesion clinic.

We demonstrate the utility of the Wood's light in a practice that specializes in the evaluation of pigmented lesions. The Wood's light assisted the physician in locating the site of a completely regressed primary cutaneous melanoma, determining the clinical borders of a lentigo maligna melanoma, differentiating between agminated naevi and a naevus spilus and detecting the recurrence of pigmentation after the excision of a dysplastic naevus, and also proved useful in monitoring a large segmental speckled atypical lentiginous naevus for change. Despite the availability of many 'high-tech' imaging and diagnostic devices designed to evaluate skin lesions, the relatively simple Wood's lamp continues to be of great value. We encourage physicians not to abandon the use of the Wood's light in their clinical practice.