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While the average lifetime risk of melanoma worldwide is approximately 3%, those with inherited high-penetrance mutations face an increased lifetime risk of 52-84%. In countries of low melanoma incidence, such as in Southern Europe, familial melanoma genetic testing may be warranted when there are two first degree relatives with a melanoma diagnosis. Testing criteria for high incidence countries such as USA, or with very-high incidence, such as Australia and New Zealand, would require a threshold of 3 to 4 affected family members. A mutation in the most common gene associated with familial melanoma, CDKN2A, is identified in approximately 10-40% of those meeting testing criteria. However, the use of multi-gene panels covering additional less common risk genes can significantly increase the diagnostic yield. Currently, genetic testing for familial melanoma is typically conducted by qualified genetic counsellors, however with increasing demand on testing services and high incidence rate in certain countries, a mainstream model should be considered. With appropriate training, dermatologists are well placed to identify high risk individuals and offer melanoma genetic test in dermatology clinics. Genetic testing should be given in conjunction with pre- and post-test consultation. Informed patient consent should cover possible results, the limitations and implications of testing including inconclusive results, and potential for genetic discrimination. Previous studies reporting on participant outcomes of genetic testing for familial melanoma have found significant improvements in both sun protective behavior and screening frequency in mutation carriers.

5-Hydroxymethylcytosine (5-hmC) is an important intermediate of DNA demethylation. Hypomethylation of DNA is frequent in cancer, resulting in deregulation of 5-hmC levels in melanoma. However, the interpretation of the intensity and distribution of 5-hmC immunoreactivity is not very standardized, which makes its interpretation difficult. In this study, 5-hmC-stained histological slides of superficial spreading melanomas (SSM) and dysplastic compound nevi (DN) were digitized and analyzed using the digital pathology and image platform QuPath. Receiver operating characteristic/area under the curve (ROCAUC) and t-tests were performed. A p -value of <0.05 was used for statistical significance, and a ROCAUC score of >0.8 was considered a "good" result. In total, 92 5-hmC-stained specimens were analyzed, including 42 SSM (45.7%) and 50 DN (54.3%). The mean of 5-hmC-positive cells/mm 2 for the epidermis and dermo-epidermal junction and the entire lesion differed significantly between DN and SSM ( p = 0.002 and p = 0.006, respectively) and showed a trend towards higher immunoreactivity in the dermal component ( p = 0.069). The ROCAUC of 5-hmC-positive cells of the epidermis and dermo-epidermal junction was 0.79, for the dermis 0.74, and for the entire lesion 0.76. These results show that the assessment of the epidermal with junctional expression of 5-hmC is slightly superior to dermal immunoreactivity in distinguishing between DN and SSM.

Early detection and treatment of melanoma, the most aggressive skin cancer, improves the median 5-year survival rate of patients from 25% to 99%. Melanoma development involves a stepwise process during which genetic changes drive histologic alterations within nevi and surrounding tissue. Herein, a comprehensive analysis of publicly available gene expression data sets of melanoma, common or congenital nevi (CN), and dysplastic nevi (DN), assessed molecular and genetic pathways leading to early melanoma. The results demonstrate several pathways reflective of ongoing local structural tissue remodeling activity likely involved during the transition from benign to early-stage melanoma. These processes include the gene expression of cancer-associated fibroblasts, collagens, extracellular matrix, and integrins, which assist early melanoma development and the immune surveillance that plays a substantial role at this early stage. Furthermore, genes up-regulated in DN were also overexpressed in melanoma tissue, supporting the notion that DN may serve as a transitional phase toward oncogenesis. CN collected from healthy individuals exhibited different gene signatures compared with histologically benign nevi tissue located adjacent to melanoma (adjacent nevi). Finally, the expression profile of microdissected adjacent nevi tissue was more similar to melanoma compared with CN, revealing the melanoma influence on this annexed tissue., (Copyright © 2023 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Acquired and congenital melanocytic naevi are common benign neoplasms. Understanding their biology and genetics will help clinicians and pathologists correctly diagnose melanocytic tumours, and generate insights into naevus aetiology and melanomagenesis. Genomic data from published studies analysing acquired and congenital melanocytic naevi, including oncogenic driver mutations, common melanoma associated mutations, copy number aberrations, somatic mutation signature patterns, methylation profile, and single nucleotide polymorphisms, were reviewed. Correlation of genomic changes to dermoscopic features, particular anatomic sites and total body naevus counts, was also performed. This review also highlights current scientific theories and evidence concerning naevi growth arrest. Acquired and congenital melanocytic naevi show simple genomes, typically characterised by mutually exclusive single oncogenic driver mutations in either BRAF or NRAS genes. Genomic differences exist between acquired and congenital naevi, common and dysplastic naevi, and by dermoscopic features. Acquired naevi show a higher rate of BRAF hotspot mutations and a lower rate of NRAS hotspot mutations compared to congenital naevi. Dysplastic naevi show upregulation of follicular keratinocyte-related genes compared to common naevi. Anatomical locations and DNA signatures of naevi implicates ultraviolet radiation and non-ultraviolet radiation pathways in naevogenesis. DNA driver point mutations in acquired and congenital melanocytic naevi have been well characterised. Future research is required to better understand transcriptional and epigenetic changes in naevi, as well as those regulating naevus growth arrest and cell environment signalling., (Copyright © 2023 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Dermatologists frequently see patients with clinically atypical nevi and dermatopathologists interpret histologically dysplastic nevi on a near-daily basis, but there is great variability in the definition and management of such lesions. This part of the CME review focuses on information published since the previous comprehensive review (2012), with emphasis on molecular and genetic attributes of histologically dysplastic nevi and clinical management., Competing Interests: Conflict of interests None disclosed., (Copyright © 2022 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

The primary differential diagnosis of melanoma is dysplastic nevus. Until now, the final diagnosis is based on histological findings. With modern techniques, pathologists receive very early melanocytic lesions, which do not fit all malignant criteria. In those cases, even the concurrence between specialists and intraobserver agreement is not good. A molecular test could be developed to improve the accuracy of melanocytic lesions diagnosis and help in challenging lesions. The objective of this study is to provide a literary review looking for molecular markers that characterize dysplastic nevi and could help surgical pathologists differentiate them from melanoma. Articles from PubMed presenting case series of dysplastic nevi and melanoma genomic analyses were considered. The search was conducted in PubMed looking for papers written in English, published in the ten years preceding April 2020. This review confirmed the absence of a pathognomonic molecular marker of dysplastic nevi. This is a heterogeneous group of lesions with an uncertain risk to become a melanoma. The molecular heterogeneity of dysplastic nevi, the variation of histological diagnostic criteria among services, and the diverse molecular techniques applied are challenging features that might hamper definitive diagnoses. However, currently, there appears to be limited value for molecular testing in the diagnosis of dysplastic nevi., Competing Interests: Declaration of competing interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: dysplastic nevi (DN) share some clinical and histological features with melanoma and have been considered intermediate lesions toward malignant transformation. However, scientific evidence of DN representing melanoma precursors is still incomplete, and many observations pointed toward their being a distinct biological entity. The current definition of DN is also confusing and the practical consequence of this uncertainty is the excessive excision of DN with severe atypia. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and whose global expression can classify normal and pathological tissues., Objectives: given these considerations, we decided to perform a small RNA profiling study in a group of DN and invasive melanomas obtained from the same patient, to assess tumor evolution according to the global microRNA expression., Methods: we performed a small-RNA sequencing of 6 DN, 2 congenital nevi and 4 cutaneous melanomas obtained from 4 subjects and evaluated the global miRNA expression correlation between samples., Results and Conclusions: the hierarchical clustering and principal component analyses of global miRNA expression, independently grouped together DN and their matching congenital nevi and showed a divergence of DN miRNA profile from melanoma. Our study suggests that DN have a peculiar and different miRNA expression profile compared to melanomas developed in the same patient, thus supporting the hypothesis that DN are distinct biological entities and not melanoma precursors., (Copyright © 2022 Elsevier GmbH. All rights reserved.)

Dysplastic nevi are distinctive melanocytic lesions in the larger group of atypical nevi. They often are multiple and sporadic with genetic features intermediate between common acquired nevi and melanoma. Dysplastic nevi may be multiple, familial, and seen in patients with familial melanoma syndrome. Although their behavior is benign, they rarely represent a precursor to melanoma. If clinically suspicious, dysplastic nevi should be removed for adequate histopathologic examination and to exclude possibility of melanoma. Partial sampling should be avoided because reliable separation from melanoma requires visualization of the entire lesion to allow for examination of architectural histopathologic features and avoid sampling error., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: We investigated the molecular causes of an unusual pigmented and ulcerated iris lesion detected in a patient diagnosed with neurofibromatosis type 1 (NF1)., Case Report: A 52-year-old man was referred to our clinic with a non-traumatic ulcer in his left eye. Hyphema reabsorption disclosed a pigmented iris mass, thus ultrasound biomicroscopy and anterior segment fluorescein angiography were performed to investigate for the presence of a malignant lesion. Upon angiography, the lesion appeared highly vascularized but prevented posterior iris examination. Therefore, a gonioscopy was executed revealing extension of the lesion into the peripheral iris. Histopathology of the excisional iris biopsy revealed iris melanoma over a dysplastic nevus. NF1 is an autosomal dominant disorder characterized by pigmented cutaneous lesions, multiple skin tumors, and spinal and cranial nerve tumors. Uveal melanoma is the most common primary intraocular malignancy in adults. Up to 92% of cutaneous melanomas occur in patients with dysplastic nevus syndrome. Skin melanomas have been found in 0.1%-5.4% of NF1 patients. In literature, only 18 reports of uveal melanoma have been documented in association with NF1, including three cases of iris melanoma., Results: NF1 gene testing identified a causative mutation in the germline but no loss of the wild-type allele in the iris melanoma., Conclusions: Occurrence of both diseases in one patient is extremely rare, but the common origin of Schwann cells and melanoblasts suggests a non-casual association. Therefore, we propose that NF1 patients should be screened for nevi, both cutaneous and uveal, for better patients' management.

Background: Fusions involving the BRAF gene are responsible for 5% of Spitz neoplasms. To better characterize them, we report the clinical, morphological, and genomic findings of six BRAF fusion Spitz tumors., Methods: The morphological, clinical, and molecular findings of six BRAF fusion Spitz neoplasms assessed by next generation sequencing (NGS) were compared to a control set of Spitz without BRAF fusions., Results: BRAF fusion Spitz tumors had frequent predominance of epithelioid morphology (4/6 cases), frequent high-grade nuclear atypia and pleomorphism (5/6 cases), and a frequent desmoplastic base (3/6 cases). Five of six cases were diagnosed as atypical Spitz tumor and one as Spitz nevus. All cases had uneventful clinical follow-up. There were five different fusion partners, with CLIP2 being the most frequent. Secondary pathogenic mutations were frequent and chromosomal copy number changes were seen in three of six cases by an NGS platform., Conclusions: BRAF fusions Spitz usually have epithelioid morphology, high-grade nuclear atypia, and desmoplasia. Chromosomal copy number changes are not infrequent. While our cases had uneventful follow-up, a meta-analysis of the literature suggests that among the fusion subtypes associated with Spitz tumors, they are among the subgroups more likely to develop distant metastasis., (© 2020 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

Background: PRAME (PReferentially expressed Antigen in MElanoma) has shown utility in distinguishing melanoma from benign melanocytic lesions, but knowledge of its expression pattern in intermediate melanocytic and spitzoid proliferations is limited., Methods: Immunohistochemical expression of PRAME was examined in 112 melanocytic proliferations with intermediate histopathologic or spitzoid features., Results: Any intensity of nuclear PRAME staining in at least 60% of lesional melanocytes was determined as the best threshold for diffuse staining in this cohort. Nearly all non-spitzoid melanomas (23/24; 95.8%) demonstrated diffuse PRAME expression. PRAME was completely negative in 95.6% (43/45) of mitotically-active nevi, traumatized nevi, nevi with persistent/recurrent features, and dysplastic nevi. Most Spitz nevi (15/20) and atypical Spitz tumors (10/13) entirely lacked PRAME expression. One Spitz nevus, one atypical Spitz tumor, and one spitzoid melanoma (1/2) demonstrated diffuse PRAME expression., Conclusions: Although diffuse PRAME expression is generally limited to malignant melanoma, benign Spitz nevi and atypical Spitz tumors can infrequently express diffuse PRAME. PRAME immunohistochemistry can be useful in the evaluation of atypical melanocytic proliferations with intermediate histopathologic features but should be interpreted with caution in the setting of spitzoid neoplasms., (© 2020 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

Familial atypical multiple mole melanoma (FAMMM) syndrome is a hereditary syndrome characterized by multiple dysplastic nevi and melanoma. Patients with FAMMM may have a heterozygous, inactivating, pathogenic germline variant in the CDKN2A gene, especially the NM&#95;000077.4: c.225&#95;243del19 (p.p75fs) variant, also known as p16-Leiden variant. Patients with this variant are at high risk for developing melanomas and pancreatic cancer due to somatic inactivation of the wild-type CDKN2A allele. The combination of an inactivating germline CDKN2A mutation and somatic inactivation of the wild-type CDKN2A allele in the same cell results in tumor formation. It has been suggested that carriers of a germline CDKN2A mutation are also at increased risk for several other cancer types, including esophageal cancer. Here, we describe two unrelated patients with the p16-Leiden variant who developed esophageal squamous cell cancer. Evidence of loss of the wild-type CDKN2A allele was obtained in the tumor tissue of both patients indicating biallelic inactivation of p16 in the tumor cells. These results suggest that these patients developed esophageal squamous cell cancer in the context of FAMMM syndrome., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Dysplastic naevus has been a controversial entity since its first description by Clark in 1978. Despite a recent paradigm shift from the initially proposed notion that dysplastic naevus is a precursor to melanoma, its management has been increasingly more aggressive in the last decade. The latter is due to an unresolved uncertainty regarding its biological nature which necessitates further clarification. Recent molecular genetics, epigenetic and transcriptomic discoveries have revealed that a subset of dysplastic naevi exhibits a genomic profile which is intermediate between that of benign naevus and melanoma. This group of lesions often shows somatic mutations in non-V600E BRAF, NRAS and TERT and hemizygous deletion of CDKN2A gene as well as upregulation of genes involved in proliferation, cell adhesion and migration, and epidermal and follicular keratinocyte-related genes. These new genomic insights suggest that a proportion of dysplastic naevi have a greater propensity to evolve to melanoma; however, the clinical and histopathological features of this proposed intermediate category are still to be elucidated by further research., (© 2019 The Australasian College of Dermatologists.)

Familial atypical multiple mole melanoma (FAMMM) syndrome is a hereditary cancer syndrome that results from mutations in several genes, including the CDKN2A gene. In addition to melanoma, certain other malignancies such as pancreatic cancer are known to occur more frequently in family members who carry the mutation. However, as these families have been followed over time, additional cancers have been observed in both carriers and noncarriers. We sought to determine whether these additional cancers occur at higher frequencies in carriers than noncarriers. We performed survival analyses using 10 FAMMM syndrome families ( N = 1,085 individuals) as well as a mixed effects Cox regression, with age at last visit to the clinic or age at cancer diagnosis as our time variable. This analysis was done separately for the known FAMMM-related cancers and "other" cancer groups. The survival curves showed a significant age effect with carriers having a younger age at cancer onset than noncarriers for FAMMM-related cancers (as expected) as well as for newly associated cancers. The Cox regression reflected what was seen in the survival curves, with all models being highly significant ( P = 7.15E-20 and P = 5.00E-13 for the FAMMM-related and other cancers, respectively). These analyses support the hypothesis that CDKN2A mutation carriers in FAMMM syndrome families have increased risk for early onset of several cancer types beyond the known cancers. Therefore, these individuals should be screened for additional cancers, and mutation screening should be extended to more than first-degree relatives of an index carrier patient. SIGNIFICANCE: This study shows that carriers of mutations in the CDKN2A gene in FAMMM syndrome are at increased risk for early onset of several cancer types beyond the known cancers., (©2019 American Association for Cancer Research.)

Background: Cyclin dependent kinase inhibitor 2A gene (CDKN2A) germline mutations have recently been associated with poor survival in patients with melanoma. Despite the high mutation rate in our cohort (up to 10% in patients with apparently sporadic melanoma), information on the impact of CDKN2A on survival in this cohort is lacking., Objective: To investigate whether poor survival associated with CDKN2A germline mutations was confirmed in a high mutation-prevalence cohort of Italian patients with melanoma undergoing a mutation-based follow-up., Methods: A total of 1239 patients with cutaneous melanoma were tested for CDKN2A mutational status and then assigned to a follow-up scheme according not only to family history but also to CDKN2A mutational status, as follow-up intervals were more frequent for CDKN2A germline mutation-positive (MUT + ) patients. From this cohort, we selected 106 MUT + patients (with familial melanoma or apparently sporadic melanoma) and 199 CDKN2A germline mutation-negative (MUT - ) patients with sporadic melanoma who were matched by age and sex and had a similar tumor stage distribution., Results: We found no difference in overall survival (hazard ratio, 0.85; 95% confidence interval, 0.48-1.52; P = .592,) or melanoma-specific survival (hazard ratio, 0.86; 95% confidence interval, 0.38-1.95; P = .718,) between MUT + and MUT - patients. MUT + patients were more likely to develop multiple melanomas and to undergo surgical excision of dysplastic nevi than were MUT - patients., Limitations: Retrospective study., Conclusion: CDKN2A mutations were not associated with survival in our cohort., (Copyright © 2018 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Since 1976, melanoma-prone families have been followed at the National Cancer Institute to identify etiologic factors for melanoma. We compared risks of melanoma and other cancers in 1,226 members of 56 families followed for up to 4 decades with population rates in the Surveillance, Epidemiology, and End Results program. All families were tested for mutations in CDKN2A and CDK4; 29 were mutation-positive and 27 mutation-negative. We compared rates of invasive melanomas, both first and second, by family mutation status, with Surveillance, Epidemiology, and End Results program. Comparing three calendar periods of the study, risk of first primary melanoma decreased slightly. Risks of melanoma after first examination, however, were approximately one-third the risks prior to the first examination in both mutation-positive and mutation-negative families. Among patients with melanoma, risk of a second melanoma was increased 10-fold in all families; risk was somewhat higher in mutation-positive families. Risks of other second cancers were increased only for pancreatic cancer after melanoma in mutation-positive families. Over 4 decades, prospective risk of melanoma has decreased substantially in both mutation-positive and mutation-negative families, when melanoma has greatly increased in the general population., Trial Registration: NCI 02-C-0211, ClinicalTrials.gov ID NCT00040352., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

A stepwise progression from melanocytic precursors to cutaneous melanoma is a well-established model, based on decades of careful observation and morphological analysis. The steps identified are benign melanocytic naevus, dysplastic naevus, 'radial growth phase' melanoma (including melanoma in situ) and 'vertical growth phase' melanoma (also termed tumourigenic melanoma). Recent genomic data have refined the understanding of the steps of melanoma development and their relationship to one another. These data support the existence of dysplastic naevi as distinct lesions; suggest the importance of clonal dynamics in the precursor steps of melanoma; and confirm the carcinogenic role of ultraviolet radiation throughout early melanoma development and progression. In this review, the steps of melanoma development and progression are summarised and discussed in the context of recent genomic studies. This new understanding of melanoma pathogenesis that has been facilitated through careful correlation of morphological and molecular features will allow the identification and development of robust biomarkers to assist in more accurate diagnosis and prognostication of melanocytic tumours., (Copyright © 2017 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Importance: Genetic testing for melanoma-prone mutation in France, a country with low to moderate incidence of melanoma, is proposed in cases with 2 invasive cutaneous melanomas and/or related cancers in the same patient, or in first- or second-degree relatives (rule of 2). In preclinical studies, these rules led to disclosure of mutation(s) in more than 10% of these families, the threshold widely accepted to justify genetic testing for cancers., Objective: To reconsider these criteria in a general population testing of patients., Design, Setting, and Participants: This was a retrospective study, performed from 2004 to 2015 at Angers and Lyons University Hospitals, of a cohort of 1032 patients who underwent genetic testing., Main Outcomes and Measures: Frequency of mutation in high (CDKN2A, CDK4, and BAP1) and intermediate (MITF) susceptibility genes; statistical effect of histologic subtype, age, dysplastic nevi syndrome, and associated cancers on mutation rate; and evaluation of cases with anamnestic uncertainty., Results: The mutation rate was 67 of 1032 patients (6.5%). Their mean (SD) age was 54.5 (14.2) years [range, 18-89 years], and 543 (52.6%) were men. It increased to 38 of 408 patients (9.3%) when applying a rule of 3 (those with ≥3 primary melanomas or genetically related cancers) (P = .68) and to 27 of 150 patients (18.0%) with a rule of 4 (4 primary melanomas or related cancer) (P < .001). The impact of age at first melanoma was observed only in those younger than 40 years, with a rate of 32 of 263 (12.1%) (P = .12) for the rule of 2 and 22 of 121 (18.2%) (P = .001) for the rule of 3. Use of the rule of 2 in patients younger than 40 years reduced the number of missed CDKN2A-mutated-families when applying the rule of 3 from 14 of 43 to 7 of 43. Anamnestic uncertainty, found in 88 families (8.5%), if excluded, would have led us to withdraw of only 21 cases (23.8%), and only 1 mutation would have been missed., Conclusions and Relevance: We propose using the rule of 3 to recommend genetic testing in France and countries with low to moderate incidence of melanoma, except in families and patients with a first melanoma occurrence before age 40 years in whom the rule of 2 could be maintained.

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant disorder caused by a mutation in the p53 gene. Melanoma is considered to be a rare, controversial component of LFS. The aim of this study is to describe the utility of systematic screening for melanoma in patients with LFS and atypical mole syndrome. Two 28-year-old identical twin sisters with LFS and atypical moles were monitored by physical examination, total-body digital photography and dermoscopy be-tween 2006 and 2014. A total of 117, predominantly dark-brown, reticular naevi were identified on case 1 and 105 on case 2. Excisions were performed during the evaluation period of 1 in-situ melanoma and 3 basal cell carcinomas in case 1, and 1 in-situ melanoma and 1 early invasive melanoma in case 2. The remaining melanocytic lesions in both patients were stable during follow-up. The 3 melanomas were new atypical lesions detected with total-body photography and dermoscopy. In conclusion, monitoring LFS patients with total-body photography and dermoscopy may be useful to detect early melanoma.

A well-defined risk factor and precursor for cutaneous melanoma is the dysplastic nevus. These benign tumors represent clonal hyperproliferation of melanocytes that are in a senescent-like state, but with occasional malignant transformation events. To portray the mutational repertoire of dysplastic nevi in patients with the dysplastic nevus syndrome and to determine the discriminatory profiles of melanocytic nevi (including dysplastic nevi) from melanoma, we sequenced exomes of melanocytic nevi including dysplastic nevi (n = 19), followed by a targeted gene panel (785 genes) characterization of melanocytic nevi (n = 46) and primary melanomas (n = 42). Exome sequencing revealed that dysplastic nevi harbored a substantially lower mutational load than melanomas (21 protein-changing mutations versus >100). Known "driver" mutations in genes for melanoma, including CDKN2A, TP53, NF1, RAC1, and PTEN, were not found among any melanocytic nevi sequenced. Additionally, melanocytic nevi including dysplastic nevi showed a significantly lower frequency and a different UV-associated mutational signature. These results show that although melanocytic nevi and dysplastic nevi harbor stable genomes with relatively few alterations, progression into melanomas requires additional mutational processes affecting key tumor suppressors. This study identifies molecular parameters that could be useful for diagnostic platforms., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Differentiation of proliferative nodules in giant congenital nevi from melanoma arising within such nevi is an important diagnostic challenge. DNA methylation is a well-established epigenetic modification already observed in the earliest stages of carcinogenesis, which increases during melanoma progression. The ten-eleven translocation enzymes catalyze the oxidation of 5-methylcytosine to 5-hydroxymethylcytosine (5-hmC), which has recently been reported as an epigenetic hallmark associated with tumor aggressiveness and poor prognosis in a wide variety of cancers. In this study, we analyzed 12 proliferative nodules and 13 melanomas both arising in giant congenital nevi and matched results with a control group including 67 benign and malignant melanocytic lesions. Proliferative nodules displayed high 5-hmC expression levels (90.65%) compared with melanomas with almost complete loss of this marker (7.87%). We showed that low 5-hmC levels in melanomas correlate with downregulation of isocitrate dehydrogenase and ten-eleven translocation families of enzymes implicated in the cytosine methylation cycle. Simultaneously, these enzymes were overexpressed in proliferative nodules leading to strong 5-hmC expression. We emphasize the significance of 5-hmC loss for discrimination of melanomas from benign proliferative nodules arising within giant congenital nevi, and for establishing the correct diagnosis in ambiguous cases when histological and immunohistochemical characteristics are not sufficiently specific., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

In this issue of Cancer Research, Almassalha and colleagues have proposed a new concept of the development of malignancy, that of the greater genomic landscape. They propose a stressor-related exploration of intracellular genomic sites as a response mechanism. This process can express sites with beneficial or deleterious effects, among them those that promote cell proliferation. They point out that their conception is broader, although certainly inclusive, of the process of gene induction. The authors view the physical process of chromatin reorganization as central to the exploration of the genomic landscape. Accordingly, they advocate the development of agents to limit chromatin structural modification as a chemotherapeutic approach in cancer. We found their theory relevant to understand the phenotypic heterogeneity of malignancy, particularly in familial cancer syndromes. For example, the familial atypical multiple mole melanoma (FAMMM) syndrome, related to a gene mutation, is characterized by a diversity of melanocytic lesions, only some of which become malignant melanoma. This new conceptualization can do much to increase understanding of the diversity of malignancy in families with hereditary cancer. Cancer Res; 76(19); 5602-4. ©2016 AACR., (©2016 American Association for Cancer Research.)

Dysplastic nevi (DNs), also known as Clark's nevi or atypical moles, are distinguished from common melanocytic nevi by variegation in pigmentation and clinical appearance, as well as differences in tissue patterning. However, cellular and molecular differences between DNs and common melanocytic nevi are not completely understood. Using cDNA microarray, quantitative RT-PCR, and immunohistochemistry, we molecularly characterized DNs and analyzed the difference between DNs and common melanocytic nevi. A total of 111 probesets (91 annotated genes, fold change > 2.0 and false discovery rate < 0.25) were differentially expressed between the two lesions. An unexpected finding in DNs was altered differentiation and activation of epidermal keratinocytes with increased expression of hair follicle-related molecules (keratin 25, trichohyalin, ribonuclease, RNase A family, 7) and inflammation-related molecules (S100A7, S100A8) at both genomic and protein levels. The immune microenvironment of DNs was characterized by an increase of T helper type 1 (IFNγ) and T helper type 2 (IL13) cytokines as well as an upregulation of oncostatin M and CXCL1. DUSP3, which regulates cellular senescence, was identified as one of the disease discriminative genes between DNs and common melanocytic nevi by three independent statistical approaches and its altered expression was confirmed by immunohistochemistry. The molecular and cellular changes in which the epidermal-melanin unit undergoes follicular differentiation as well as upregulation of defined cytokines could drive complex immune, epidermal, and pigmentary alterations., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Genital melanomas (GM) are the second most common cancer of the female external genitalia and may be confused with atypical genital nevi (AGN), which exhibit atypical histological features but have benign behavior. In this study, we compared the clinical, histological, and molecular features of 19 GM and 25 AGN. We described chromosomal copy number aberrations and the mutational status of 50 oncogenes and tumor suppressor genes in both groups. Our study showed that a pigmented lesion occurring in mucosal tissue, particularly in postmenopausal women, was more likely to be a melanoma than a nevus. GM had high levels of chromosomal instability, with many copy number aberrations. Furthermore, we found a completely nonoverlapping pattern of oncogenic mutations when comparing GM and AGN. In GM, we report somatic mutations in KIT and TP53. Conversely, AGN had frequent BRAF V600E mutations, which were not seen in any of the GM. Our results show that GM and AGN have distinct clinical and molecular changes and that GM have a different mutational pattern compared with AGN., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The similar genetic background of a pair of twins, and the similar environmental impacts to which they are exposed allow an exact and objective investigation of various constitutional and environmental factors in naevus development. As far as we are aware, this is the first published survey that simultaneously examines cutaneous and ocular pigmented lesions in an appreciable sample of identical and non-identical twins., Methods: 172 pairs of twins of Caucasian origin were included in this study. A whole-body skin examination and a detailed ophthalmological examination were performed to determine the density of melanocytic lesions. A standardized questionnaire was used to assess the data relating to constitutional, sun exposure and other variables., Results: A notably high proportion of the subjects (36.78%) manifested one or more clinically atypical melanocytic naevi (CAMNs), and approximately one-third (31.4%) of them at least one benign uveal pigmented lesion (BUPL). The incidence of iris freckles (IFs), iris naevi (INs) and choroidal naevi (CHNs) proved to be 25.35%, 5.98% and 3.52%, respectively. The interclass correlation coefficients for common melanocytic naevi (CMNs), CAMNs, and INs were 0.77, 0.76 and 0.86 in monozygotic twins, as compared with 0.5, 0.27 and 0.25 in dizygotic twin pairs, respectively. A statistically significant correlation was found between the prevalence of CAMNs and that of INs., Conclusions: This significant correlation suggests the existence of a subgroup of Caucasian people with an increased susceptibility to both cutaneous and ocular naevus formation. There is accumulating evidence that, besides the presence of cutaneous atypical naevi, INs can serve as a marker of a predisposed phenotype at risk of uveal melanoma. The correlation between cutaneous and ocular pigmented lesions underlines the need for the adequate ophthalmological screening of subjects with CAMNs and INs.

Approximately 5-10 % of cutaneous melanoma occurs in kindreds with a hereditary predisposition. Mutations in the CDKN2A gene are found to occur in approximately 20-40 % of these kindreds. The first historical mention of what is now called the familial atypical multiple mole melanoma syndrome appears to be from 1820, with more reports throughout the 1950s, 1960s, and later years. In 1991, Lynch and Fusaro described an association between familial multiple mole melanoma and pancreatic cancer and work continues to elucidate the syndrome's genotypic and phenotypic heterogeneity. Individuals at risk for familial melanoma need periodic screenings. Unfortunately, adequate screening for pancreatic cancer does not currently exist, but pancreatic cancer's prominence in the hereditary setting will hopefully act as a stimulus for development of novel screening measures.

Some melanocytic tumors can be histologically ambiguous causing diagnostic difficulty, which could lead to overtreatment of benign lesions with an unwarranted psychological distress or undertreatment of malignant cancers. Previously, we demonstrated that significantly decreased miR-211 expression in melanomas compared with melanocytic nevi could accurately discriminate malignant from benign tumors. Herein we show microRNA in situ hybridization for fluorescent detection of miR-211, suitable for paraffin-embedded tissues in 109 primary melanocytic tumors. miR-211 expression was significantly lower in melanomas vs nevi (P<0.0001), and receiver operating characteristic curve (area under the curve=0.862) accurately discriminated melanomas from nevi with 90% sensitivity and 86.2% specificity. Qualitatively, all dysplastic nevi expressed miR-211 at high (86%) and low (14%) levels, independent of the degree of nuclear atypia. All 35 melanocytic tumors with Spitz morphology expressed miR-211 independent of morphological classification, where clinical follow-up of these patients showed no recurrence at the site or metastasis in mean and median of 3 (ranging 2-5) years. Moreover, a decision tree learning analysis selected age and miR-211 miRNA in situ hybridization as the predictive variables for benign or malignant outcome in 88 patients correctly classified 92% (81 out of 88) of cases as proven by receiver operating characteristic curve (area under the curve=0.9029). These results support miR-211 as a leading miRNA candidate for melanoma diagnosis and miRNA in situ hybridization as a uniquely uncomplicated ancillary test.

We describe a rare case of a 28 year-old male patient presenting with pruritus and increased sensitivity of the prepuce accompanied by erythematous confluent papules, unilateral nevus flammeus (NF) along almost the whole length of the right lower limb and two dysplastic nevi (DN), one located on the mid back and the other on the medial border of the right fifth toe, the latter coinciding with the NF. A biopsy of the prepuce revealed lichen sclerosus et atrophicus (LSA). Mental health assessment revealed anxiety disorder and predisposition to panic attacks. Several clinical, paraclinical and histopathological examinations were undertaken to evaluate potential underlying factors for such unusual combination of findings. Both dysplastic nevi were surgically removed. A topical calcineurin inhibitor treatment of the LSA was prescribed. For the first time in medical literature, we report an extremely rare association of NF, DN (including DN over NF) and LSA, and we are focusing our discussion on a potentially common genetic background which could explain this unusual combination of different diseases, which could in turn be caused by different mutations in common genes and/or different genes with close location in the genome.

Tumours progress to fully malignant neoplasms through stages of development in a stepwise process. A carcinogenic stimulus such as UV light typically results in a large number of lesions, most of which are benign. Most such lesions will remain stable or regress, while a few will develop cytological and architectural atypia, placing them in a morphologically 'intermediate' category between wholly benign and fully malignant. It is important to categorise intermediate lesions, as they may be simulants, risk markers, and potential precursors of malignancy. Although many but not all malignancies arise in an evident precursor lesion, the vast majority of 'potential precursors' will not progress, as is evidenced by their vastly greater numbers in populations. Progression continues with the onset of malignancy including in metastatic disease. In melanoma as in other tumours, progression has been clearly related to the stepwise acquisition of genetic abnormalities. The first step is the activation of a single 'driver' oncogene, which is sufficient to induce a benign neoplasm whose growth is limited by oncogene-induced senescence driven by activated suppressors. In the intermediate lesions, additional genetic alterations occur such as additional driver mutations or heterozygous loss of suppressors due to copy number variation or other mechanisms. Fully malignant lesions are characterised by complete loss of relevant suppressors and by additional abnormalities, which together account for attributes of malignancy such as invasion and metastasis. Any of the steps of progression can be 'skipped', potentially due to telescoped progression or to alternative pathways. Although stages of progression might simply be viewed as markers of an individual's risk for developing subsequent stages, genetic associations that have been demonstrated among contiguous stages of progression in complex primary tumours and in their metastases would argue against this. For example, complex primary melanomas can be associated with remnants of earlier stage lesions both clinically and histologically. These include small symmetrical benign naevi and/or morphologically atypical dysplastic naevi ('precursor naevi'), and/or radial growth phase melanomas many of which may be inexorably progressive but lack competence for metastasis. Vertical growth phase is the stage of melanoma progression in which risk for metastasis may be acquired. This risk can be characterised statistically using prognostic attributes which at present are mostly clinicopathological, although in the future molecular profiling may contribute or even supplant these attributes. In metastatic disease, tumours can continue to progress, acquiring resistance to various therapeutic strategies which presents a considerable challenge to the efficacy of current promising therapeutic strategies., (Copyright © 2016. Published by Elsevier B.V.)

Importance: Several kindreds having germline BAP1 mutations with a propensity for uveal and cutaneous melanomas and other internal malignancies have been described in an autosomal dominant tumor predisposition syndrome. However, clinically atypical moles have not been previously recognized as a component of this syndrome, to our knowledge. We describe the first kindred to date with a germline mutation in BAP1 associated with multiple cutaneous melanomas and classic dysplastic nevus syndrome., Observations: We describe a 53-year-old man who was initially seen in 2003 with dysplastic nevus syndrome, multiple atypical melanocytic proliferations showing loss of immunostaining for BAP1, and 7 cutaneous melanomas. Germline testing was performed in the proband, his 16-year-old son, and his 13-year-old daughter, revealing a germline mutation in the BAP1 gene (c.592G>T, p.Glu198X) in the proband and in his 16-year-old son. CDKN2A and CDK4 genes were wild type. No members of this kindred reported a history of uveal melanoma., Conclusions and Relevance: To our knowledge, this is the first report of a patient with multiple melanomas, dysplastic nevus syndrome, and an inactivating germline BAP1 mutation. The coexistence of dysplastic nevus syndrome and a BAP1 germline mutation extends the spectrum of the BAP1 tumor predisposition syndrome and may confer a greater risk for cutaneous melanomas.

Background: The p16-Leiden founder mutation in the CDKN2A gene is the most common cause of Familial Atypical Multiple Mole Melanoma (FAMMM) syndrome in the Netherlands. Individuals with this mutation are at increased risk for developing melanoma of the skin, as well as pancreatic cancer. However, there is a notable interfamilial variability in the occurrence of pancreatic cancer among p16-Leiden families. We aimed to test whether previously identified genetic risk factors for pancreatic cancer modify the risk for pancreatic cancer in p16-Leiden germline mutation carriers., Methods: Seven pancreatic cancer-associated SNPs were selected from the literature and were genotyped in a cohort of 185 p16-Leiden germline mutation carriers from 88 families, including 50 cases (median age 55 years) with pancreatic cancer and 135 controls (median age 64 years) without pancreatic cancer. Allelic odds ratios per SNP were calculated., Results: No significant association with pancreatic cancer was found for any of the seven SNPs., Conclusions: Since genetic modifiers for developing melanoma have already been identified in CDKN2A mutation carriers, this study does not exclude that genetic modifiers do not play a role in the individual pancreatic cancer risk in this cohort of p16-Leiden germline mutation carriers. The search for these modifiers should therefore continue, because they can potentially facilitate more targeted pancreatic surveillance programs.

The criterion standard for diagnosing cutaneous melanoma continues to be histologic examination. However, classifying some melanocytic lesions by conventional microscopy can be problematic if they exhibit some architectural or morphologic characteristics of both nevus and melanoma. Moreover, histologic appearance does not always predict biologic behavior. There is therefore a need and opportunity to develop new technologies that can facilitate the histologic diagnosis of melanoma and potentially help distinguish lesions with a lesser or greater risk of metastasis. In part II of this 2-part continuing medical education article, we will review the molecular technologies currently available for facilitating melanoma diagnosis, including comparative genomic hybridization, fluorescence in situ hybridization, and epidermal genetic retrieval. Our goal is to provide the clinician with an up to date understanding of these molecular approaches so that they can be applied to their management of challenging melanocytic lesions., (Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Importance: The BRAF V600E mutation accounts for the majority of BRAF mutations found in cutaneous melanoma and is also commonly found in nevi. We used dermoscopy-targeted sampling and a microbiopsy device coupled with DNA sequence analysis to highlight BRAF V600E heterogeneity within a multicomponent melanocytic proliferation. This sampling technique demonstrates the prospect of in vivo application in a clinical setting., Observations: A man in his 50s with Fitzpatrick skin type II presented with an irregularly pigmented melanocytic lesion on his back that met melanoma-specific dermoscopic criteria, and diagnostic shave excision of the lesion was performed. Histopathologic analysis revealed a melanoma in situ arising in a dysplastic nevus. Dermoscopy-targeted microbiopsy specimens were taken across the lesion, and genotyping was carried out on extracted DNA samples for BRAF and NRAS mutations. The melanoma in situ showed only BRAF wild-type results, while the dysplastic nevus showed both BRAF wild-type and BRAF V600E mutations. Sequencing in all DNA samples revealed NRAS wild-type genotype., Conclusions and Relevance: Dermoscopy-targeted sampling and genotyping of a melanoma in situ arising in a dysplastic nevus revealed a phenotype-genotype paradox that confounds the exclusive significance of BRAF and NRAS mutations in melanoma pathogenesis. Further studies are required to investigate the importance of other candidate genes linked to melanomagenesis.

Dysplastic nevus is still a controversial entity both clinically and histologically. The occurrence of dysplastic nevus especially in the context of dysplastic nevus cell syndrome is associated with an increased risk for melanoma. The following minimal histological criteria should be fulfilled: nests of melanocytes varying in size and shape, bridging and confluent, proliferation of single melanocytes basal and suprabasal, cytoplasmic and nuclear atypia of melanocytes and subepidermal fibroplasia. The biological behavior (common nevus variant or precursor of melanoma?) is difficult to evaluate by presently available methods. The further development of new molecular biology techniques may allow a better prognosis of dysplastic nevi in an objective and reproducible manner. Against this background complete excision followed by clinical surveillance has to be recommended for the routine practice.

Dysplastic nevi are melanocytic lesions that represent an intermediate stage between common nevus and melanoma. Histopathological distinction of dysplastic nevus from melanoma can be challenging and there is a requirement for molecular diagnostic markers. In this study, we examined promoter CpG island methylation of a selected panel of genes, identified in a genome-wide methylation screen, across a spectrum of 405 melanocytic neoplasms. Promoter methylation analysis in common nevi, dysplastic nevi, primary melanomas, and metastatic melanomas demonstrated progressive epigenetic deregulation. Dysplastic nevi were affected by promoter methylation of genes that are frequently methylated in melanoma but not in common nevi. We assessed the diagnostic value of the methylation status of five genes in distinguishing primary melanoma from dysplastic nevus. In particular, CLDN11 promoter methylation was specific for melanoma, as it occurred in 50% of primary melanomas but in only 3% of dysplastic nevi. A diagnostic algorithm that incorporates methylation of the CLDN11, CDH11, PPP1R3C, MAPK13, and GNMT genes was validated in an independent sample set and helped distinguish melanoma from dysplastic nevus (area under the curve 0.81). Melanoma-specific methylation of these genes supports the utility as epigenetic biomarkers and could point to their significance in melanoma development.

There is growing evidence that not only malign keratinocytic but also melanocytic tumours can arise during treatment with vemurafenib. During an on-going early access trial, 13 patients harbouring a BRAF-V600E mutation received vemurafenib (Zelboraf®) 960 mg twice daily to test the safety, tolerability, efficacy and response rate for advanced melanoma. Clinically or dermatoscopically suspicious cutaneous tumours under treatment with vemurafenib were excised. The BRAF-V600E status of confirmed new primary melanoma and dysplastic naevi was tested using a genetic mutation assay and immunohistochemistry. Four of the 13 patients (31%) developed 4 new naevi-associated malignant melanomas and 5 dysplastic naevi between 6 weeks and 6 months after the start of treatment. With the exception of one in situ melanoma, all tumours were BRAF wild-type. Immunohistochemistry revealed increased expression of ERK, pERK and active Rac1-GTP in the naevi-associated melanoma and dysplastic naevi. Careful and continuous skin examination, including dermoscopy, appears to be required during treatment with vemurafenib.

Ultraviolet (UV) radiation-induced DNA damage and genomic instability is one of the leading causes for melanoma. X-ray repair cross-complementary protein 1, XRCC1, plays a critically important role in base excision repair pathway. This study was therefore performed to analyze the correlation between XRCC1 expression, melanoma progression, and patient survival. Using a tissue microarray with a total of 119 patients with melanoma, we demonstrate that loss of XRCC1 expression is associated with the progression of disease from dysplastic nevi to primary melanoma and to metastatic melanoma. We found that the loss of XRCC1 was correlated with the progression of melanoma from AJCC stage II to stage III and with worse overall and disease-specific 5-yr and 10-yr survival of patients with melanoma. Furthermore, we also illustrate the inhibitory effect of XRCC1 on melanoma cell invasion and migration, which are the regulatory events in melanoma metastasis., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Proto-oncogene B-Raf (BRAF) mutation rates have been reported in nevi and melanomas of homogeneous Caucasian cohorts., Objective: To study the demographics of BRAF mutations in dysplastic nevi of populations with differing potential solar UV radiation exposure., Methods: Extended BRAF testing for 9 mutations in 125 dysplastic nevi from 101 patients, derived from populations with differing potential UV radiation exposure rates (Lebanon and Saudi Arabia), was performed. Clinical and microscopic parameters were recorded., Results: BRAF mutation status was carried out for 101/125 (80.8%) cases with an overall mutation rate of 62.4% (63/101). V600E (c.1799T > A) was the predominant mutation, found in 61/63 (96.8%) cases. BRAF mutation rate differed significantly by potential UV radiation exposure (Lebanon: 53.4%, Saudi Arabia: 74.4%, P < 0.05). A 43.8% discordant mutation rate (7/16 patients) was found in patients with multiple nevi, including 2 patients with different BRAF mutations. Microscopic examination subdivided the dysplasia into mild (n = 24), moderate (n = 60) and severe (n = 41) with trunk predominance (72.8%). Higher rates of pigment in the stratum corneum were identified in Saudi Arabia (P < 0.05). No statistical significant increase in BRAF mutation rate was noted with advanced architectural and cytological atypia. Parameters associated with a negative BRAF mutation status included upper extremity location, regression, cohesiveness and presence of suprabasal melanocytes (P < 0.05). Positive BRAF mutation status was reasonably predicted by multivariate binary logistic regression by 2 independent predictors: Geographic location and compound nevus type., Conclusions: In our Near Eastern cohort, the BRAF mutation rate varied significantly by geographic location. In patients with multiple dysplastic nevi examined, discordant BRAF mutation status potentially negates an underlying constitutional predilection., (© 2013 The Authors Journal of the European Academy of Dermatology and Venereology © 2013 European Academy of Dermatology and Venereology.)

Dysplastic nevi (DN) is a strong risk factor for cutaneous malignant melanoma (CMM), and it frequently occurs in melanoma-prone families. To identify genetic variants for DN, we genotyped 677 tagSNPs in 38 melanoma candidate genes that are involved in pigmentation, DNA repair, cell cycle control, and melanocyte proliferation pathways in a total of 504 individuals (310 with DN, 194 without DN) from 53 melanoma-prone families (23 CDKN2A mutation positive and 30 negative). Conditional logistic regression, conditioning on families, was used to estimate the association between DN and each single-nucleotide polymorphism (SNP) separately, adjusted for age, sex, CMM, and CDKN2A status. P-values for SNPs in the same gene were combined to yield gene-specific P-values. Two genes, CDK6 (cyclin-dependent kinase 6) and XRCC1, were significantly associated with DN after Bonferroni correction for multiple testing (P=0.0001 and 0.00025, respectively), whereas neither gene was significantly associated with CMM. Associations for CDK6 SNPs were stronger in CDKN2A mutation-positive families (rs2079147, Pinteraction=0.0033), whereas XRCC1 SNPs had similar effects in mutation-positive and -negative families. The association for one of the associated SNPs in XRCC1 (rs25487) was replicated in two independent data sets (random-effect meta-analysis: P<0.0001). Our findings suggest that some genetic variants may contribute to DN risk independently of their association with CMM in melanoma-prone families.

Distinct genetic aberrations between melanomas in different anatomical locations have been confirmed in recent years. However, the associations between immunohistochemical expression, tumor sites, and clinical parameters are not clear. We examined the correlation of protein expression and gene mutation of c-kit with clinicopathological parameters and lesion locations in patients with malignant melanoma (MM). We collected 170 melanocytic lesions, including 106 cutaneous MM from acral melanoma (AM) and nonacral melanoma (NAM) sites, 24 dysplastic nevi, and 40 common melanocytic nevi. Tissue microarray was constructed, and immunohistochemical expression for c-kit was assessed with correlation with clinical parameters. Mutation in exons 11, 13, 17, and 18 of KIT gene in genomic DNA by polymerase chain reaction sequencing was also analyzed. Immunostaining scores for c-kit were found to be statistically higher in Dysplastic Nevi than in common melanocytic nevi and MM. In addition, cytoplasmic c-kit staining was significantly correlated with poor survival in patients with AM but not in those with NAM. Twenty-nine cases of MM (including 9 NAM and 20 AM) are analyzed for mutation in exons 11, 13, 17, and 18 of KIT gene in genomic DNA by polymerase chain reaction sequencing, and no genetic mutation is found. Our findings confirm that KIT mutations, in contrast to previous white cohorts, are not common in both AM and NAM of the Chinese and do not necessarily correlate with c-kit expression. The significantly different association between the expression of c-kit immunoreactivities and the mortality risks of melanomas on acral versus nonacral sites might change site-specific targeted therapeutic concepts in melanoma in the future.

Cutaneous melanoma is a malignant tumor of melanocytes that causes the majority of skin cancer-related deaths. However, sometimes, discrimination between dysplastic nevi and early melanomas is difficult, even for experienced pathologists. Besides histology, the silencing of tumor suppressor genes aids in the diagnosis of melanoma. We have shown previously that tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene, and its silencing through aberrant promoter methylation is associated with the generation of cutaneous melanoma. To examine TSLC1 expression in melanocytic skin lesions to determine whether it can serve as a diagnostic marker in histologically questionable lesions. Cytoplasmic localization of the expression of the TSLC1 gene was detected by immunohistochemistry; the levels of TSLC1 mRNA and protein were detected by quantitative real-time reverse transcription-PCR and western blot, respectively. Using immunohistochemistry, the average TSLC1 expression levels in cutaneous melanomas decreased approximately 3.6-fold (n=20) as compared with dysplastic nevi (n=30) and 3.7-fold as compared with normal skin (n=25). The average expression levels of TSLC1 mRNA and protein in dysplastic nevi lesions and normal skin were significantly higher than the levels in cutaneous melanomas. No significant changes in TSLC1 mRNA and protein expressions were found between normal skin and dysplastic nevi. Our results show that a loss of TSLC1 frequently occurs in cutaneous melanoma, and indicate that it could serve as a diagnostic marker for cutaneous melanoma in histologically questionable lesions.

Future classification systems for melanocytic neoplasms will likely include the integration of molecular aberrations. A number of studies have shown that many gene mutations and chromosomal copy number aberrations may correlate with characteristic clinical and morphologic features for melanocytic neoplasms. This review discusses newly described familial germline mutations such as the BRCA1-associated protein-1 familial melanoma syndrome, recently described somatic mutations, and chromosomal copy number aberrations recently described in melanoma. Further, we discuss how these specific molecular aberrations correlate with specific clinical and morphologic features in melanocytic neoplasm and their implications for prognosis and molecular diagnostics. In addition, we discuss state of the art advancements in molecular diagnostics for melanocytic neoplasms and newly developed fluorescence in situ hybridization assays including the utility of fluorescence in situ hybridization for 9p21 in spitzoid melanocytic neoplasms. Lastly, we discuss a phenomenon known as paradoxical activation of wild-type BRAF seen in patients treated with vemurafenib and some potential clinical presentations of this process.

The dysplastic nevus is a discreet histologic entity that exhibits some clinical and histologic features overlapping with common nevi and melanoma. These overlapping features present a therapeutic challenge, and with a lack of accepted guidelines, the management of dysplastic nevi remains a controversial subject. Although some differences between dysplastic and common nevi can be detected at the molecular level, there are currently no established markers to predict biologic behavior. In part II of this continuing medical education article, we will review the molecular aspects of dysplastic nevi and their therapeutic implications. Our goal is to provide the clinician with an up-to-date understanding of this entity to facilitate clinical management of patients with nevi that have histologic dysplasia., (Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)

Since its description in the 1970s, the dysplastic nevus has been a source of confusion, and whether it represents a precursor to melanoma remains a controversial subject. Although a Consensus Conference in 1992 recommended that the term "dysplastic nevus" no longer be used, the histologic diagnosis continues to present a therapeutic quandary for dermatologists and other physicians, and there remains significant variation in clinical management. In part I of this continuing medical education review, we will discuss the historical origins of the term, the evidence for its distinct histologic basis, and its clinical significance., (Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)

Dysplastic nevi have been a subject of much debate since their original description in 1978. Although some question the biological potential of dysplastic nevi themselves, several studies have shown that their presence confers substantial risk for melanoma. In addition to predisposing patients to melanoma, dysplastic nevi have been shown to harbor genetic mutations, indicating their position on a continuum between banal nevi and melanomas. Dysplastic nevi are also clinically relevant as mimickers of melanoma, and can be challenging diagnostically. This article reviews the history, epidemiology, biology and genetics, clinical features, histopathologic features, and management guidelines for patients with these lesions., (Copyright © 2012 Elsevier Inc. All rights reserved.)