Dermoscopy of Lentiginous Melanomas and Equivocal Benign Pigmented Macules of the Scalp: A Case-Control Multicentric Study.

INTRODUCTION: Although the dermoscopic features of facial lentiginous melanomas (LM), including lentigo maligna and lentigo maligna melanoma, have been extensively studied, the literature about those located on the scalp is scarce. This study aims to describe the dermoscopic features of scalp LM and assess the diagnostic accuracy of dermoscopy to discriminate them from equivocal benign pigmented macules. METHODS: Consecutive cases of scalp LM and histopathology-proven benign but clinically equivocal pigmented macules (actinic keratoses, solar lentigos, seborrhoeic keratoses, and lichen planus-like keratoses) from four referral centres were included. Dermoscopic features were analysed by two blinded experts. The diagnostic performance of a predictive model was assessed. RESULTS: 56 LM and 44 controls were included. Multiple features previously described for facial and extrafacial LM were frequently identified in both groups. Expert's sensitivity to diagnose scalp LM was 76.8% (63.6-87.0) and 78.6% (65.6-88.4), with specificity of 54.5% (38.9-69.6) and 56.8% (41.0-71.7), and fair agreement (kappa coefficient 0.248). The strongest independent predictors of malignancy were (OR, 95% CI) chaos of colour (15.43, 1.48-160.3), pigmented reticular lines (14.96, 1.68-132.9), increased density of vascular network (3.45, 1.09-10.92), and perifollicular grey circles (2.89, 0.96-8.67). The predictive model achieved 85.7% (73.8-93.6) sensitivity, 61.4% (45.5-75.6) specificity, and 81.5 (73.0-90.0) area under curve to discriminate benign and malignant lesions. A diagnostic flowchart was proposed, which should improve the diagnostic performance of dermoscopy. CONCLUSION: Both facial and extrafacial dermoscopic patterns can be identified in scalp LM, with considerable overlap with benign pigmented macules, leading to low specificity and interobserver agreement on dermoscopy.

The Additive Value of 3D Total Body Imaging for Sequential Monitoring of Skin Lesions: A Case Series.

BACKGROUND: Timely diagnosis is the cornerstone of melanoma morbidity and mortality reduction. 2D total body photography and dermoscopy are routinely used to assist with early detection of skin malignancies. Polarized 3D total body photography is a novel technique that enables fast image acquisition of almost the entire skin surface. We aimed to determine the added value of 3D total body photography alongside dermoscopy for monitoring cutaneous lesions. METHODS: Lesion images from high-risk individuals were assessed for long-term substantial changes via dermoscopy and 3D total body photography. Three case studies are presented demonstrating how 3D total body photography may enhance lesion analysis alongside traditional dermoscopy. RESULTS: 3D total body photography can assist clinicians by presenting cutaneous lesions in their skin ecosystem, thereby providing additional clinical context and enabling a more holistic assessment to aid dermoscopy interpretation. For lesion cases where previous dermoscopy is unavailable, corresponding 3D images can substitute for baseline dermoscopy. Additionally, 3D total body photography is not susceptible to artificial stretch artefacts. CONCLUSION: 3D total body photography is valuable alongside dermoscopy for monitoring cutaneous lesions. Furthermore, it is capable of surveilling almost the entire skin surface, including areas not traditionally monitored by sequential imaging.

Reproducible Naevus Counts Using 3D Total Body Photography and Convolutional Neural Networks.

BACKGROUND: The number of naevi on a person is the strongest risk factor for melanoma; however, naevus counting is highly variable due to lack of consistent methodology and lack of inter-rater agreement. Machine learning has been shown to be a valuable tool for image classification in dermatology. OBJECTIVES: To test whether automated, reproducible naevus counts are possible through the combination of convolutional neural networks (CNN) and three-dimensional (3D) total body imaging. METHODS: Total body images from a study of naevi in the general population were used for the training (82 subjects, 57,742 lesions) and testing (10 subjects; 4,868 lesions) datasets for the development of a CNN. Lesions were labelled as naevi, or not ("non-naevi"), by a senior dermatologist as the gold standard. Performance of the CNN was assessed using sensitivity, specificity, and Cohen's kappa, and evaluated at the lesion level and person level. RESULTS: Lesion-level analysis comparing the automated counts to the gold standard showed a sensitivity and specificity of 79% (76-83%) and 91% (90-92%), respectively, for lesions ≥2 mm, and 84% (75-91%) and 91% (88-94%) for lesions ≥5 mm. Cohen's kappa was 0.56 (0.53-0.59) indicating moderate agreement for naevi ≥2 mm, and substantial agreement (0.72, 0.63-0.80) for naevi ≥5 mm. For the 10 individuals in the test set, person-level agreement was assessed as categories with 70% agreement between the automated and gold standard counts. Agreement was lower in subjects with numerous seborrhoeic keratoses. CONCLUSION: Automated naevus counts with reasonable agreement to those of an expert clinician are possible through the combination of 3D total body photography and CNNs. Such an algorithm may provide a faster, reproducible method over the traditional in person total body naevus counts.

Methods of melanoma detection and of skin monitoring for individuals at high risk of melanoma: new Australian clinical practice.

INTRODUCTION: The evidence-based national clinical practice guidelines for the management of cutaneous melanoma published in 2008 are currently being updated. This article summarises the findings from multiple chapters of the guidelines on different methods of melanoma detection and of monitoring the skin for patients at high risk of melanoma. Early detection of melanoma is critical, as thinner tumours are associated with enhanced survival; therefore, strategies to improve early detection are important to reduce melanoma-related mortality. MAIN RECOMMENDATIONS: Clinicians who perform skin examinations for the purpose of detecting skin cancer should be trained in and use dermoscopy. The use of short term sequential digital dermoscopy imaging to detect melanomas that lack dermoscopic features of melanoma is recommended to assess individual melanocytic lesions of concern. The use of long term sequential digital dermoscopy imaging to detect melanomas that lack dermoscopic features of melanoma is recommended to assess individual or multiple melanocytic lesions for routine surveillance of high risk patients. The use of total body photography should be considered in managing patients at increased risk for melanoma, particularly those with high naevus counts and dysplastic naevi. There is insufficient evidence to recommend the routine use of automated instruments for the clinical diagnosis of primary melanoma. MANAGEMENT OVERVIEW: Determining the relative indications for each diagnostic method and how each method should be introduced into the surveillance of a patient requires careful consideration and an individualised approach.

A prospective observational study of pigmented naevi changes in psoriasis patients on biologic therapy.

BACKGROUND/OBJECTIVES: Patients on biologic therapy are thought to be at increased risk of developing non-melanoma skin cancers and melanomas. It is unknown whether biologic therapy alters the natural history of melanocytic naevi. Therefore, a prospective observational study was conducted to determine whether psoriasis patients on biologic therapy develop changes in naevi. METHODS: Clinical and dermoscopic assessment of all melanocytic naevi was performed in 45 psoriasis patients on biologic therapy versus a control cohort of 43 subjects, using sequential digital dermoscopic imaging and total body photography. The mean follow-up period was 1.5 years. RESULTS: The study and control patients had comparable age, gender, previous and family history of non-melanoma skin cancers and melanomas, as well as previous sun exposure and total number of naevi. The number of naevi with major dermoscopic changes was 3% in the study and 1.9% in the control group, with an adjusted incidence rate ratio of 1.45 (95% confidence interval 0.90-2.33; P = 0.125). The rate of minor changes was 15.9% in the study group versus 19.4% in the control (adjusted incidence rate ratio 0.77, 95% confidence interval 0.57-1.08; P = 0.14). There were six new dysplastic naevi in 4/45 biologic patients and four in 4/43 controls; however, the difference was not significant (relative risk 0.96, 95% confidence interval -0.12 to 0.12; P = 0.95). There were no melanomas in either group. CONCLUSION: Over a mean follow-up period of 1.5 years there was no evidence of significantly different changes in naevi or development of new dysplastic naevi in psoriasis patients on biologic treatment compared to controls.

The steadily growing problem of lentigo maligna and lentigo maligna melanoma in Australia: Population-based data on diagnosis and management.

BACKGROUND/OBJECTIVES: There are limited population-based data documenting the incidence and management of lentigo maligna (LM) and invasive lentigo maligna melanoma (LMM). We report the data on occurrence and management of LM and LMM in an Australian population. METHODS: Prospective collection of incidence and clinician-reported management of melanoma in situ (MIS; n = 450, capped) and localised invasive melanoma (n = 3251) notified to the New South Wales Cancer Registry over 12-months in 2006-2007. RESULTS: The estimated annual incidence of all MIS was 27.0 per 100 000 (LM 12.2, non-LM MIS 5.9 and unclassified MIS 9.0). Patients with LM or LMM were on average approximately 10 years older than those with other melanoma subtypes (P < 0.001). The head and neck was the location of 59% of LM, 44% of LMM and <20% of other melanoma subtypes (P < 0.001). The majority of LM and LMM were treated only by specialists. Diagnostic partial biopsies were more frequent for LM and LMM than for other melanoma subtypes, and primary care physicians were more likely than specialists to do a punch partial biopsy than a shave biopsy. The reported median definitive excision margin for LM was 5.0 mm compared with 7.2 mm for non-LM MIS (P = 0.001). CONCLUSIONS: In this Australian population, LM was twice as frequent as other types of MIS. Improved strategies for diagnosis and management are required.

Punch 'scoring': a technique that facilitates melanoma diagnosis of clinically suspicious pigmented lesions.

AIMS: Early recognition and accurate diagnosis underpins melanoma survival. Identifying early melanomas arising in association with pre-existing lesions is often challenging. Clinically suspicious foci, however small, must be identified and examined histologically. This study assessed the accuracy of punch biopsy 'scoring' of suspicious foci in excised atypical pigmented skin lesions to identify early melanomas. METHODS AND RESULTS: Forty-one excised pigmented skin lesions with a clinically/dermoscopically focal area of concern for melanoma, with the suspicious focus marked prior to excision with a punch biopsy 'score' (a partial incision into the skin surface), were analysed. Melanoma was diagnosed in nine of 41 cases (22%). In eight of nine cases (89%) the melanoma was associated with a naevus, and in seven of nine (88%) cases the melanoma was identified preferentially by the scored focus. In six of nine cases (67%), the melanoma was entirely encompassed by the scored focus. In one case of melanoma in situ, the diagnostic material was identified only on further levelling through the scored focus. In 28 of 32 of non-melanoma cases (88%), the scored focus identified either diagnostic features of a particular lesion or pathological features that correlated with the clinical impression of change/atypia including altered architecture or distribution of pigmentation, features of irritation or regression. CONCLUSIONS: The 'punch scoring technique' allows direct clinicopathological correlation and facilitates early melanoma diagnosis by focusing attention on clinically suspicious areas. Furthermore, it does not require special expertise in ex-vivo clinical techniques for implementation. Nevertheless, in some cases examination of the lesion beyond the scored focus is also necessary to make a diagnosis of melanoma.

Accuracy of dermatoscopy for the diagnosis of nonpigmented cancers of the skin.

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.

Diagnosis and clinical management of melanoma patients at higher risk of a new primary melanoma: A population-based study in New South Wales, Australia.

BACKGROUND/OBJECTIVES: To describe the method of diagnosis, clinical management and adherence to clinical practice guidelines for melanoma patients at high risk of a subsequent primary melanoma, and compare this with melanoma patients at lower risk. METHODS: The Melanoma Patterns of Care study was a population-based, observational study based on doctors' reported clinical management of melanoma patients in New South Wales, Australia, diagnosed with in situ or invasive melanoma over a 12-month period from October 2006. Of 2605 patients with localised melanoma, 1019 (39%) were defined as at higher risk due to the presence of one or more of the following factors: a family history of melanoma (11%), multiple primary melanomas (17%), or many naevi (24%). RESULTS: Compared to patients at lower risk, high risk patients were more likely to receive their initial care from a primary care physician (56% vs 50%, P = 0.002), have their melanoma detected during a routine skin check (40% vs 33%, P < 0.001), have their lesion assessed with dermoscopy (63% vs 56%, P = 0.002), and be encouraged to have skin surveillance (84% vs 77%, P < 0.001) and skin self-examination (87% vs 83%, P = 0.03). Higher socioeconomic status and urban residence were associated with patients at higher risk receiving initial treatment from a specialist doctor. CONCLUSIONS: Clinical management of higher risk patients was more likely to conform to clinical practice guidelines for diagnosis and skin surveillance than to melanoma patients at lower risk.

Follow-up of early stage melanoma: specialist clinician perspectives on the functions of follow-up and implications for extending follow-up intervals.

BACKGROUND: There is limited evidence on the relative effectiveness of different follow-up schedules for patients with AJCC stage I or II melanoma, but less frequent follow-up than is currently recommended has been proposed. OBJECTIVES: To describe melanoma clinicians' perspectives on the functions of follow-up, factors that influence follow-up intervals, and important considerations for extending intervals. METHODS: Qualitative interviews with 16 clinicians (surgical oncologists, dermatologists, melanoma unit physicians) who conduct follow-up at two of Australia's largest specialist centers. RESULTS: Follow-up is conducted for early detection of recurrences or new primary melanomas, to manage patient anxiety, support patient self-care, and as part of shared care. Recommended intervals are based on guidelines but account for each patient's clinical risk profile, level of anxiety, patient education requirements, capacity to engage in skin self-examination, and how the clinician prefers to manage any suspicious lesions. CONCLUSIONS: To revise guidelines and implement change it is important to understand the rationale underpinning existing practice. Extended follow-up intervals for early stage melanoma are more likely to be adopted after the first year when patients are less anxious and sufficiently prepared to conduct self-examination. Clinicians may retain existing schedules for highly anxious patients or those unable to examine themselves.

Negative pigment network: an additional dermoscopic feature for the diagnosis of melanoma.

BACKGROUND: The negative pigment network (NPN) is seen as a negative of the pigmented network and it is purported to be a melanoma-specific structure. OBJECTIVES: We sought to assess the frequency, sensitivity, specificity, and odds ratios (ORs) of NPN between melanoma cases and a group of control lesions. METHODS: Digitalized images of skin lesions from 679 patients with histopathological diagnosis of dermatofibroma (115), melanocytic nevus (220), Spitz nevus (139), and melanoma (205) were retrospectively collected and blindly evaluated to assess the presence/absence of NPN. RESULTS: The frequency of occurrence of NPN was higher in the melanoma group (34.6%) than in Spitz nevus (28.8%), melanocytic nevus (18.2%), and dermatofibroma (11.3%) groups. An OR of 1.8 emerged for the diagnosis of melanoma in the presence of NPN as compared with nonmelanoma diagnosis. Conversely, for melanocytic nevi and dermatofibromas the OR was very low (0.5 and 0.3, respectively). For Spitz nevi the OR of 1.1 was not statistically significant. When comparing melanoma with dermatofibroma, melanocytic nevus, and Spitz nevus, we observed a significantly higher frequency of multicomponent pattern (68.1%), asymmetric pigmentation (92.9%), irregularly distributed NPN (87.3%), and peripheral location of NPN (66.2%) in melanomas. LIMITATIONS: Further studies can provide the precise dermoscopic-histopathologic correlation of NPN in melanoma and other lesions. CONCLUSIONS: The overall morphologic pattern of NPN, such as the irregular distribution and the peripheral location of NPN, along with the multicomponent pattern and the asymmetric pigmentation could be used as additional features in distinguishing melanoma from Spitz nevus and other benign lesions.

Skin cancer excisions and histopathology outcomes when following a contemporary population-based cohort longitudinally with 3D total-body photography.

Background: Skin cancer represents a significant health burden across the globe and early detection is critical to improve health outcomes. Three-dimensional (3D) total-body photography is a new and emerging technology which can support clinicians when they monitor people's skin over time. Objectives: The aim of this study was to improve our understanding of the epidemiology and natural history of melanocytic naevi in adults, and their relationship with melanoma and other skin cancers. Methods: Mind Your Moles was a 3-year prospective, population-based cohort study which ran from December 2016 to February 2020. Participants visited the Princess Alexandra Hospital every 6 months for 3 years to undergo both a clinical skin examination and 3D total-body photography. Results: A total of 1213 skin screening imaging sessions were completed. Fifty-six percent of participants (n = 108/193) received a referral to their own doctor for 250 lesions of concern, 101/108 (94%) for an excision/biopsy. Of those, 86 people (85%) visited their doctor and received an excision/biopsy for 138 lesions. Histopathology of these lesions found 39 non-melanoma skin cancers (across 32 participants) and six in situ melanomas (across four participants). Conclusions: 3D total-body imaging results in diagnosis of a high number of keratinocyte cancers (KCs) and their precursors in the general population.

Comparison of humans versus mobile phone-powered artificial intelligence for the diagnosis and management of pigmented skin cancer in secondary care: a multicentre, prospective, diagnostic, clinical trial.

BACKGROUND: Diagnosis of skin cancer requires medical expertise, which is scarce. Mobile phone-powered artificial intelligence (AI) could aid diagnosis, but it is unclear how this technology performs in a clinical scenario. Our primary aim was to test in the clinic whether there was equivalence between AI algorithms and clinicians for the diagnosis and management of pigmented skin lesions. METHODS: In this multicentre, prospective, diagnostic, clinical trial, we included specialist and novice clinicians and patients from two tertiary referral centres in Australia and Austria. Specialists had a specialist medical qualification related to diagnosing and managing pigmented skin lesions, whereas novices were dermatology junior doctors or registrars in trainee positions who had experience in examining and managing these lesions. Eligible patients were aged 18-99 years and had a modified Fitzpatrick I-III skin type; those in the diagnostic trial were undergoing routine excision or biopsy of one or more suspicious pigmented skin lesions bigger than 3 mm in the longest diameter, and those in the management trial had baseline total-body photographs taken within 1-4 years. We used two mobile phone-powered AI instruments incorporating a simple optical attachment: a new 7-class AI algorithm and the International Skin Imaging Collaboration (ISIC) AI algorithm, which was previously tested in a large online reader study. The reference standard for excised lesions in the diagnostic trial was histopathological examination; in the management trial, the reference standard was a descending hierarchy based on histopathological examination, comparison of baseline total-body photographs, digital monitoring, and telediagnosis. The main outcome of this study was to compare the accuracy of expert and novice diagnostic and management decisions with the two AI instruments. Possible decisions in the management trial were dismissal, biopsy, or 3-month monitoring. Decisions to monitor were considered equivalent to dismissal (scenario A) or biopsy of malignant lesions (scenario B). The trial was registered at the Australian New Zealand Clinical Trials Registry ACTRN12620000695909 (Universal trial number U1111-1251-8995). FINDINGS: The diagnostic study included 172 suspicious pigmented lesions (84 malignant) from 124 patients and the management study included 5696 pigmented lesions (18 malignant) from the whole body of 66 high-risk patients. The diagnoses of the 7-class AI algorithm were equivalent to the specialists' diagnoses (absolute accuracy difference 1·2% [95% CI -6·9 to 9·2]) and significantly superior to the novices' ones (21·5% [13·1 to 30·0]). The diagnoses of the ISIC AI algorithm were significantly inferior to the specialists' diagnoses (-11·6% [-20·3 to -3·0]) but significantly superior to the novices' ones (8·7% [-0·5 to 18·0]). The best 7-class management AI was significantly inferior to specialists' management (absolute accuracy difference in correct management decision -0·5% [95% CI -0·7 to -0·2] in scenario A and -0·4% [-0·8 to -0·05] in scenario B). Compared with the novices' management, the 7-class management AI was significantly inferior (-0·4% [-0·6 to -0·2]) in scenario A but significantly superior (0·4% [0·0 to 0·9]) in scenario B. INTERPRETATION: The mobile phone-powered AI technology is simple, practical, and accurate for the diagnosis of suspicious pigmented skin cancer in patients presenting to a specialist setting, although its usage for management decisions requires more careful execution. An AI algorithm that was superior in experimental studies was significantly inferior to specialists in a real-world scenario, suggesting that caution is needed when extrapolating results of experimental studies to clinical practice. FUNDING: MetaOptima Technology.

Shared care in the follow-up of early-stage melanoma: a qualitative study of Australian melanoma clinicians' perspectives and models of care.

BACKGROUND: Patients with early stage melanoma have high survival rates but require long-term follow-up to detect recurrences and/or new primary tumours. Shared care between melanoma specialists and general practitioners is an increasingly important approach to meeting the needs of a growing population of melanoma survivors. METHODS: In-depth qualitative study based on semi-structured interviews with 16 clinicians (surgical oncologists, dermatologists and melanoma unit GPs) who conduct post-treatment follow-up at two of Australia's largest specialist referral melanoma treatment and diagnosis units. Interviews were recorded, transcribed and analysed to identify approaches to shared care in follow-up, variations in practice, and explanations of these. RESULTS: Melanoma unit clinicians utilised shared care in the follow-up of patients with early stage melanoma. Schedules were determined by patients' clinical risk profiles. Final arrangements for delivery of those schedules (by whom and where) were influenced by additional psychosocial, professional and organizational considerations. Four models of shared care were described: (a) surgical oncologist alternating with dermatologist (in-house or local to patient); (b) melanoma unit dermatologist and other local doctor (e.g. family physician); (c) surgical oncologist and local doctor; or (d) melanoma physician and local doctor. CONCLUSIONS: These models of shared care offer alternative solutions to managing the requirements for long-term follow-up of a growing number of patients with stage I/II melanoma, and warrant further comparative evaluation of outcomes in clinical trials, with detailed cost/benefit analyses.

Results of a nationwide dermoscopy survey investigating the prevalence, advantages and disadvantages of dermoscopy use among Australian dermatologists.

BACKGROUND/OBJECTIVES: The primary objective of this survey was to assess the prevalence of use of dermoscopy by Australian dermatologists. The secondary objective was to understand the perceived advantages and disadvantages of dermoscopy use. METHODS: Invitation letters were sent to all 282 Australian dermatologists belonging to the Australasian College of Dermatology in 2008. The survey, investigating prevalence and perceptions of dermoscopy use, was completed either online or on paper. RESULTS: Ninety-nine of the 283 (35%) dermatologists completed the survey eligibly. A total of 98% of dermatologists reported using dermoscopy and 95% had received formal training. Only 2-3% found it not useful for the diagnosis of pigmented lesions, melanoma or atypical naevi, whereas 12% found it not useful for the diagnosis of non-pigmented tumours. Eighty-five percent found it improved diagnosis compared to naked eye examination; and 57% of dermatologists used baseline dermoscopy to follow up changes in lesions, of which 78% used some image capture device. CONCLUSIONS: In the sample of Australian dermatologists agreeing to be surveyed, there was a high prevalence rate of dermoscopy use. The factors supporting the use of dermoscopy are explored in this foundational database of dermoscopy use among Australian dermatologists.

Short-Term Lesion Change Detection for Melanoma Screening With Novel Siamese Neural Network.

Short-term monitoring of lesion changes has been a widely accepted clinical guideline for melanoma screening. When there is a significant change of a melanocytic lesion at three months, the lesion will be excised to exclude melanoma. However, the decision on change or no-change heavily depends on the experience and bias of individual clinicians, which is subjective. For the first time, a novel deep learning based method is developed in this paper for automatically detecting short-term lesion changes in melanoma screening. The lesion change detection is formulated as a task measuring the similarity between two dermoscopy images taken for a lesion in a short time-frame, and a novel Siamese structure based deep network is proposed to produce the decision: changed (i.e. not similar) or unchanged (i.e. similar enough). Under the Siamese framework, a novel structure, namely Tensorial Regression Process, is proposed to extract the global features of lesion images, in addition to deep convolutional features. In order to mimic the decision-making process of clinicians who often focus more on regions with specific patterns when comparing a pair of lesion images, a segmentation loss (SegLoss) is further devised and incorporated into the proposed network as a regularization term. To evaluate the proposed method, an in-house dataset with 1,000 pairs of lesion images taken in a short time-frame at a clinical melanoma centre was established. Experimental results on this first-of-a-kind large dataset indicate that the proposed model is promising in detecting the short-term lesion change for objective melanoma screening.