PRAME is a useful marker for the differential diagnosis of melanocytic tumours and histological mimics.

AIMS: Although the morphological assessment of melanoma is generally straightforward, diagnosis can be especially difficult when the significant morphological and immunohistochemical results overlap with those of benign and malignant melanocytic tumours and histological mimics. This study assessed the potential diagnostic utility of measuring PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemically in naevi, melanomas and clear cell sarcomas (CCSs) in Chinese patients. METHODS: We examined the immunohistochemical expression of PRAME in 317 melanocytic naevi, 178 primary melanomas, 72 metastatic melanomas and 19 CCSs and compared the sensitivity and specificity of PRAME immunohistochemistry (IHC) in the differential diagnosis of melanocytic tumours and histological mimics. RESULTS: Of the 317 melanocytic naevi, 98.1%were completely negative for PRAME; six cases showed focal PRAME immunoreactivity in a minor population of lesional melanocytes. Diffuse nuclear immunoreactivity for PRAME was found in 89.9% of primary melanomas and 93.1% of metastatic melanomas. Regarding melanoma subtypes, PRAME was expressed in 100% of superficial spreading melanomas, 100% of melanomas arise in congenital naevus, 91.4% of nodular melanomas, 87.8% of acral lentigo melanomas, 80.0% of lentigo malignant melanomas, 60.0% of Spitz melanomas, 96.2% of mucosal melanomas and 80.0% of uveal melanomas. None of the two desmoplastic melanomas expressed PRAME. Of the 19 CCS cases, 89.5% were negative for PRAME and 10.5% showed focal weak PRAME immunoreactivity in a minor population of tumour cells. CONCLUSIONS: Our findings indicate that PRAME may be a useful marker to support a suspected diagnosis of melanoma. In addition, lack of PRAME expression is a valuable hint to CCS in a suspected case, and then molecular confirmation of the presence of EWSR1 rearrangement is necessary.

Ultra-high-frequency ultrasound and machine learning approaches for the differential diagnosis of melanocytic lesions.

Malignant melanoma (MM) is one of the most dangerous skin cancers. The aim of this study was to present a potential new method for the differential diagnosis of MM from melanocytic naevi (MN). We examined 20 MM and 19 MN with a new ultra-high-frequency ultrasound (UHFUS) equipped with a 70 MHz linear probe. Ultrasonographic images were processed for calculating 8 morphological parameters (area, perimeter, circularity, area ratio, standard deviation of normalized radial range, roughness index, overlap ratio and normalized residual mean square value) and 122 texture parameters. Colour Doppler images were used to evaluate the vascularization. Features reduction was implemented by means of principal component analysis (PCA), and 23 classification algorithms were tested on the reduced features using histological response as ground-truth. Best results were obtained using only the first component of the PCA and the weighted k-nearest neighbour classifier; this combination led to an accuracy of 76.9%, area under the ROC curve of 83%, sensitivity of 84% and specificity of 70%. The histological analysis still remains the gold-standard, but the UHFUS images processing using a machine learning approach could represent a new non-invasive approach.

Development of a Checklist Tool to Assess the Quality of Skin Lesion Images Acquired by Consumers Using Sequential Mobile Teledermoscopy.

BACKGROUND: Mobile teledermoscopy is an emerging technology that involves imaging and digitally sending dermoscopic images of skin lesions to a clinician for assessment. High-quality, consistent images are required for accurate telediagnoses when monitoring lesions over time. To date there are no tools to assess the quality of sequential images taken by consumers using mobile teledermoscopy. The purpose of this study was to develop a tool to assess the quality of images acquired by consumers. METHODS: Participants imaged skin lesions that they felt were concerning at baseline, 1-, and 2-months. A checklist to assess the quality of consumer sequential imaging of skin lesions was developed based on the International Skin Imaging Collaboration guidelines. A scale was implemented to grade the quality of the images: 0 (low) to 18 (very high). Intra- and inter-reliability of the checklist was assessed using Bland-Altman analysis. Using this checklist, the consistency with which 85 sets of images were scored by 2 evaluators were compared using Kappa statistics. Items with a low Kappa value <0.4 were removed. RESULTS: After reliability testing, 5 of the items were removed due to low Kappa values (<0.4) and the final checklist included 13 items surveying: lesion selection; image orientation; lighting; field of view; focus and depth of view. Participants had a mean age of 41 years (range 19-73), and 67% were female. Most participants (84%, n = 71/85) were able to select and image the correct lesion over time for both the dermoscopic and overview images. Younger participants (<40 years old) scored significantly higher (8.1 ± 2.1) on the imaging checklist compared to older participants (7.1 ± 2.4; p = 0.037). Participants had most difficulty with consistent image orientation. CONCLUSIONS: This checklist could be used as a triage tool to filter images acquired by consumers prior to telediagnosis evaluation, which would improve the efficiency and accuracy of teledermatology and teledermoscopy processes. It may also be used to provide feedback to the consumers to improve image acquisition over time.

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.

Eruptive Cherry Angiomas and Skin Melanoma: Further Insights into an Intriguing Association.

BACKGROUND: Some risk factors for malignant melanoma (MM) are recognized. OBJECTIVE: To compare the strength of association between MM and eruptive cherry angiomas (CAs) with that of other well-known associations. METHODS: This cross-sectional study included all subjects referred to the Outpatient Dermatology-Oncology and Dermoscopy Units of the Universities of Ferrara and Bologna, Italy, over a 5-month period and submitted to total body skin examination. We recorded: age, sex, cutaneous and non-cutaneous malignancies, presence of CAs, arbitrarily considered as "eruptive" when >10, >40 common melanocytic naevi or >2 clinically atypical naevi. The strength of association between the possible risk factors and MM was calculated by odds ratio in both the whole population and age quartiles. Variables associated with MM were included in multiple logistic regression analysis. RESULTS: 1,190 subjects were included; 615 had malignant skin tumours, 462 MM, 85 extracutaneous tumours. Five hundred and eighty-seven subjects had eruptive CAs, 485 subjects >40 melanocytic naevi and 368 more than 2 atypical melanocytic naevi. Eruptive CAs, especially in subjects younger than 70, and >2 atypical melanocytic naevi, mostly in subjects older than 50, were significantly associated with MM. The strength of these 2 associations was similar. The presence of >40 melanocytic naevi was not associated with MM. CONCLUSIONS: These findings confirmed an association between MM and eruptive CAs, which was as strong as the one between MM and >2 atypical melanocytic naevi. CAs seem an intriguing model of interaction between heterogeneous variables, like immunocompetence, stimuli inducing endothelial cell proliferation, and oncogenesis, which deserves further investigation.

Phenotypic Characteristics and Melanoma Thickness in Women.

Patients' phenotypic characteristics might be associated with melanoma aggressiveness, but the evidence is scarce. This study examined the associations be-tween pigmentary characteristics, naevi and melanoma thickness. Data from the Norwegian Women and Cancer (NOWAC) study were analysed. By 2014, 1,243 women were diagnosed with a primary melanoma, and 1,140 had information on thickness. Using ordinal logistic regression models, the probability of being diagnosed with a specific thickness category was calculated by pigmentary score and naevi. Fair pigmentary score was associated with thinner trunk melanomas (probabilities of being diagnosed with a tumour ≤1.0 mm thickness were 74%, 66%, and 51% for fair, medium and dark pigmentary scores, respectively), but not the other sites. High number of naevi was associated with thicker nodular melanoma (NM) but not with super-ficial spreading melanoma. These findings suggest the need for greater overall vigilance and skin checks among women with fair pigmentary score. The association between naevi and NM suggest possible biological mechanisms.

Visual Impact of Large and Giant Congenital Naevi: Comparison of Surgical Scars with Naevi Before Surgery.

Surgical attempts to remove large/giant congenital melanocytic naevi (LGCMN) are supported mainly by the theoretical improvement in patients' self-image; however such surgery can result in unaesthetic scarring. We hypothesize that difference in appearance itself has an impact, and hence surgery cannot negate this impact. The aim of this cross-sectional study was to explore how LGCMN and scarring are perceived by non-affected people. We surveyed the visual impact on 1,015 health and non-health professionals working in a university hospital. Participants were assigned to 1 of 3 surveys, which, based on photographs of children: (i) assessed the visual impact of LGCMN; (ii) the visual impact of scarring; (iii) compared the impact of LGCMN and scarring. Feelings and perceptions evoked by images of children, either with LGCMN or with scarring, were remarkably similar. However, when the images of the same child (with LGCMN or scarring) were shown together, respondents showed significantly increased preference for scarring.

Cross-sectional study of pigmented lesions of the head and neck in adults aged 40 years and above.

The diagnosis of junctional and lentiginous naevi on sun-damaged skin of the head and neck in adults has been questioned in the literature, with the implication that these lesions should be classified as melanoma in situ. This could result in the overdiagnosis and overtreatment of non-malignant lesions. We conducted a cross-sectional study of the histopathological diagnosis of pigmented lesions biopsied from the head and neck of adults ≥40 years of age that were submitted to a large, Queensland-based pathology centre over seven months. Out of 543 lesions assessed, 293 (54.0%) were flat and 250 (46.0%) were raised. Flat naevi consisted of junctional/lentiginous and compound naevi, either with or without dysplasia. Collectively, flat naevi had a prevalence slightly less than that of melanoma (15.0% versus 19.0% among flat lesions, respectively, and 8.1% versus 11.2% among all lesions, respectively). The mean age of biopsy for all junctional/lentiginous naevi was significantly greater than that of all compound naevi (65.0 years versus 52.2 years; P = 0.001). Junctional/lentiginous naevi were significantly more associated with the neck than intradermal naevi (P < 0.001). In conclusion, benign, flat naevi account for a significant proportion of head and neck lesions in adults ≥40 years of age, and their location alone should not outweigh their histopathology when reaching a diagnosis.

Congenital melanocytic naevi: An up-to-date overview.

Congenital melanocytic naevi are hamartomas of the neuroectoderm caused by genetic mosaicism. Congenital melanocytic naevi are seen in 1-6% of all live births and commonly classified based on the projected size in adults. Congenital melanocytic naevi appear in different colours, shapes, and sizes, and occasionally present with complications. In this review, we sought to evaluate congenital melanocytic naevi, their clinical, dermatoscopic, and reflectance confocal microscopic features, behavioural pattern over time, new trends in classification, underlying genetic factors and their influence on clinical manifestations and management, associated risks, complications, magnetic resonance imaging findings and their management in the light of recent literature.

Neck Melanoma: Clinical, Dermoscopic and Confocal Features.

BACKGROUND: The head and neck are considered one single anatomical unit. No data on clinical, dermoscopic and confocal aspects of neck melanoma are currently available. OBJECTIVES: To identify clinical, dermoscopic and confocal diagnostic features of neck melanomas. METHODS: Consecutive malignant (cases) and benign (controls) melanocytic skin lesions located on the neck, excised as suspected of being melanoma from March 2011 to February 2018, were retrospectively retrieved. Dermoscopic criteria of the 7-point checklist, integrated by other melanoma features (such as grey colour and irregular hyperpigmented areas) were assessed. Reflectance confocal microscopy (RCM) images were examined when available. RESULTS: 282 lesions located to the head and neck area were biopsied to rule out melanoma. Thirty-one out of 282 (11%) lesions were located on the neck: 21 melanomas and 10 naevi. Melanoma patients were older than patients with naevi (mean age: 60.4 vs. 37.9 years, p < 0.001). Neck melanomas were more frequently located on sun-damaged skin compared to naevi (76.2 vs. 30%, p = 0.02). Dermoscopically, neck melanomas were characterized by irregular dots/globules, grey colour and regression (76.2, 81 and 46.7% of cases) and showed criteria of lentigo maligna melanoma (LMM) in 52.4% of cases. Regression, grey colour, irregular hyperpigmented areas and criteria of LMM typified melanomas on sun-damaged skin, whereas tumours located on non-sun-damaged areas were often characterized by irregular pigmentation (blotches). RCM, implemented to dermoscopy, correctly diagnosed 10/12 melanomas and 3/5 naevi. CONCLUSION: Neck melanoma has peculiar clinical and dermoscopic aspects that could help clinicians to distinguish it from naevi and to diagnose melanoma earlier.

Management of Congenital Melanocytic Naevi in Children: A French National Survey Using Clinical Vignettes.

Management of congenital melanocytic naevi in childhood may vary depending on the habits and experience of the treating clinician. The aim of this study was to assess current practice and determinants of surgical excision decision-making among French physicians. A national survey was conducted among dermatologists, paediatricians and surgeons, using clinical vignettes illustrating 29 scenarios. The primary outcome was the decision to perform surgical excision in each vignette. Of the 11,310 decisions made by the 390 participants (257 dermatologists, 35 surgeons, and 98 paediatricians) surgical excision was chosen in 33% of cases. The stated motivations for performing surgical excision were: melanoma risk, aesthetic/psychosocial risk, or both, in 39%, 34% and 27% of cases, respectively. Physicians with a higher level of experience in oncodermatology were more likely to opt for surgical excision. The age of the child, the size of the congenital melanocytic naevi, and the visibility of the lesion had no influence on the decision to perform surgical excision.

It's Not All Sunshine: Non-sun-related Melanoma Risk-factors.

There is increasing evidence that the behaviour of naevi and melanoma is under significant genetic and/or epigenetic control. Melanoma tumours behaves similarly all over the world. Many genes have now been implicated in melanoma risk and naevi number. Embryogenesis has also been important in the discovery of links between several neurological diseases and melanoma susceptibility. Telomere biology, which regulates cell senescence, is increasingly relevant in melanoma. Melanoma is often found in the context of family cancer syndromes and the identification of these families is important as screening for cancer will save lives. Melanoma is also one of the most immunogenic cancer as the behaviour of naevi and melanoma differ in patients with vitiligo or eczema. The search for non-sun related melanoma risk factors should continue as it is likely to lead to important discoveries which will, in turn, have an impact on therapeutic targets for this tumour.

Massively parallel sequencing analysis of benign melanocytic naevi.

AIMS: Melanocytic naevi are benign lesions of the skin or mucosa that may constitute non-obligate precursors of malignant melanoma, particularly when they show lentiginous and dysplastic features. The aim of this study was to investigate the repertoire of somatic genetic alterations in melanocytic naevi. METHODS AND RESULTS: DNA extracted from 12 melanocytic naevi and DNA from matching normal tissue were separately microdissected and subjected to targeted massively parallel sequencing of ≥300 cancer genes. A median of 5.5 (range 1-12) non-synonymous somatic mutations were detected, with 10 cases harbouring mutually exclusive BRAF V600E (6/12) or NRAS (4/12) clonal hotspot mutations. One of the two cases lacking BRAF and NRAS mutations was a dysplastic naevus harbouring an HRAS Q61L hotspot mutation. Analysis of the laser-capture microdissected components of a naevus synchronously diagnosed with in-situ and invasive malignant melanoma revealed a truncal, clonal BRAF V600E mutation, and the acquisition of a CDKN2A homozygous deletion in the invasive component, in conjunction with additional clonal mutations affecting NF2, FAT4 and KDR in both in-situ and invasive malignant components. CONCLUSION: Melanocytic naevi harbour recurrent BRAF V600E or NRAS hotspot mutations with low mutational burdens. Our findings also show that progression from naevi to malignant melanoma may be driven by the acquisition of additional genetic alterations, including CDKN2A homozygous deletions.

Defining the Molecular Genetics of Dermoscopic Naevus Patterns.

Melanocytic naevi are common melanocytic proliferations that may simulate the appearance of cutaneous melanoma. Naevi commonly harbour somatic mutations implicated in melanomagenesis but in most cases lack the necessary genomic alterations required for melanoma development. While the mitogen-activated protein kinase pathway and ultraviolet radiation strongly contribute to naevogenesis, the somatic mutational landscape of dermoscopic naevus subsets distinguishes some of the molecular hallmarks of naevi in relation to melanoma. We herein discuss the classification of naevi and theories of naevogenesis and review the current literature on the somatic alterations in naevi and melanoma. This review focusses on the clinical-dermoscopic-pathological and genomic correlation of naevi that shapes the current understanding of naevi.

Clinical and Dermoscopic Evaluation of Melanocytic Lesions in Patients with Chronic Graft Versus Host Disease.

Patients treated with haematopoietic stem cell transplantation are at increased risk of cutaneous malignant neoplasms. There are no reports on the characteristics of melanocytic lesions in patients with chronic graft versus host disease and the value of recognizing these difficult lesions in high-risk patients. The objective of this study is to describe the clinical and dermoscopic characteristics of melanocytic lesions in patients with chronic graft versus host disease in order to understand their morphology. A prospective cross-sectional study was performed; 10 melanocytic lesions on the trunk and extremities were selected from each patient. A statistically significant association was found between regression and high total dermoscopic score and 7-point checklist score. Lesions were excised or included in short-term digital follow-up. Melanocytic lesions in patients with chronic graft versus host disease developing after allogeneic-haematopoietic stem cell transplantation exhibit marked structural and colour changes similar to melanoma. This is believed to result from the inflammatory process associated with graft versus host disease.

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.

Melanoma risk stratification of individuals with a high-risk naevus phenotype - A pilot study.

BACKGROUND/OBJECTIVES: High a naevus counts and atypical naevi are risk factors for cutaneous melanoma. However, many individuals with a high-risk naevus phenotype do not develop melanoma. In this study, we describe the clinical and dermoscopic attributes of naevi associated with melanoma in a high-risk naevus phenotype population. METHODS: This single-centre, hospital-based case-control study included 54 prospectively enrolled adult patients ≥18 years old with a high-risk naevus phenotype (18 cases with a history of melanoma and 36 age- and gender-matched controls without a history of melanoma). We analysed clinical and dermoscopic images of the 20 largest naevi for each participant. RESULTS: Cases had a higher mean age than controls (48.2 vs. 39.1 years, P = 0.007) but there was no difference in the male-to-female ratio between groups. Nearly, all participants (97%) were Fitzpatrick skin type II or III. Naevi in cases were more likely to be truncal, (72.6% vs. 53.6%, P = 0.01), particularly anterior truncal, (29.2% vs. 14.4%, P < 0.001) and larger than 8 mm (17.4% vs. 7.8%%, P = 0.01) compared to controls. CASH score of naevi did not differ between groups. Naevi in cases were more likely to have a multicomponent dermoscopic pattern than in controls (18.4% vs. 12.6%, P = 0.02). CONCLUSION: Larger naevi, truncal naevi, and naevi, with a multicomponent dermoscopic pattern may be risk factors for melanoma among individuals with a high-risk naevus phenotype. Further studies are needed to validate these findings.

Melanocytic naevi with perineurial differentiation: a distinctive variant of neurotised naevi and a diagnostic pitfall with desmoplastic melanoma.

AIMS: Spindle cell differentiation is not an uncommon finding in common acquired naevi, and may represent a form of neurotisation with Schwannian differentiation of melanocytes. Perineurial differentiation in this context appears to be very rare, and is only poorly documented in the literature. We therefore aimed to study this rare form of neurotisation in melanocytic naevi more comprehensively. METHODS AND RESULTS: We have identified six melanocytic tumours showing spindle cell morphology and perineurial differentiation from routine and referral material. Clinical data and follow-up were obtained, and the histological and immunohistochemical features were analysed. The tumours affected middle-aged adults (median, 48 years; range, 26-74 years), with a wide anatomical distribution and benign follow-up (median, 13 months; range, 6-48 months). All tumours were nodular and circumscribed but asymmetrical, with extension into the deep dermis and superficial subcutis. A characteristic finding was a biphasic growth pattern with a lentiginous compound naevus in the superficial aspect and abrupt transition to a prominent nodular spindle cell proliferation in the deeper reaches. Spindle cells were bland and uniform, and arranged singly and in short fascicles in a loose fibromyxoid stroma. In areas, a whorled arrangement of slender spindle cells with wavy nuclei was seen. Distinctive intratumoral hypocellular nodules and peripheral lymphoid aggregates were additional features. By immunohistochemistry, the spindle cells were mainly S100-positive melanocytes. In areas, S100-negative/epithelial membrane antigen-positive spindle cells showing coexpression of Glut-1 and claudin-1 were closely admixed. CONCLUSION: This perineurial differentiation probably represents a rare and unusual form of neurotisation. The tumours are benign but may be mistaken for desmoplastic melanoma. Awareness of and careful attention to the clinicopathological and immunohistochemical features allow reliable separation.

Oesophageal epidermal naevi as a feature of systematised epidermal naevus syndrome.

Systematised epidermal naevi are hamartomas developing from neural ectoderm that can be quite extensive, typically with involvement of the face, neck, scalp, arms, legs and trunk. Involvement of the gastrointestinal tract is rare. We report on a 38-year-old Caucasian woman with systematised epidermal naevus syndrome who presented with previously undescribed involvement of the oesophagus, as well as the right side of her scalp, forehead, cheeks, chin, oral mucosa, neck, arms and trunk.

The management of dysplastic naevi: a survey of Australian dermatologists.

BACKGROUND/OBJECTIVES: The management of dysplastic naevi based on histopathological grading is a contentious issue. Comprehensive management guidelines are lacking and the approach taken varies between clinicians. The authors sought to understand how Australian dermatologists approach the management of biopsy-proven dysplastic naevi, and the impact of grading of dysplasia upon this management. METHODS: In total, 547 Fellows of the Australasian College of Dermatologists were surveyed and 218 responses were collected (40% response rate). RESULTS: Although all dermatologists surveyed would re-excise an incompletely removed severely dysplastic naevus, opinion was divided over whether to treat such a lesion as an in situ melanoma or a dysplastic naevus, with 55% of respondents using a 5-mm margin and the remainder opting for narrow margin re-excision. When the same lesion was reported to be clear of margins by 1 mm after biopsy and the clinical suspicion for melanoma was high, 44% would re-excise with a 5-mm margin. CONCLUSIONS: The approach of Australian dermatologists to the management of dysplastic naevi varies between clinicians, reflecting the problems raised by the validity of histopathological grading.