Clinical and dermoscopic characteristics of congenital and noncongenital nevus-associated melanomas

Dermoscopy of melanoma according to different body sites: Head and neck, trunk, limbs, nail, mucosal and acral

Effective cancer screening detects early-stage tumours, leading to a lower incidence of late-stage disease over time. Dermoscopy is the gold standard for skin cancer diagnosis as diagnostic accuracy is improved compared to naked eye examinations. As melanoma dermoscopic features are often body site specific, awareness of common features according to their location is imperative for improved melanoma diagnostic accuracy. Several criteria have been identified according to the anatomical location of the melanoma. This review provides a comprehensive and contemporary review of dermoscopic melanoma criteria according to specific body sites, including frequently observed melanoma of the head/neck, trunk and limbs and special site melanomas, located on the nail, mucosal and acral region.

LSM2 is associated with a poor prognosis and promotes cell proliferation, migration, and invasion in skin cutaneous melanoma

BACKGROUND

Skin cutaneous melanoma (SKCM) is an extremely malignant tumor that is associated with a poor prognosis. LSM2 has been found to be related to different types of tumors; however, its role in SKCM is poorly defined. We aimed to determine the value of LSM2 as a prognostic biomarker for SKCM.

METHODS

The expression profile of LSM2 mRNA was compared between tumor and normal tissues in public databases, such as TCGA, GEO, and BioGPS. LSM2 protein expression was explored using immunohistochemistry (IHC) on a tissue microarray containing 44 SKCM tissues and 8 normal samples collected at our center. Kaplan-Meier analysis was performed to assess the prognostic value of LSM2 expression in patients with SKCM. SKCM cell lines with LSM2 knockdown were used to determine the effects of LSM2. Cell counting kit-8 (CCK8) and colony formation assays were conducted to assess cell proliferation, whereas wound healing and transwell assays were carried out to assess the migration and invasion abilities of SKCM cells.

RESULTS

LSM2 was more highly expressed at the mRNA and protein levels in SKCM than that in normal skin. Moreover, elevated expression of LSM2 was associated with shorter survival time and early recurrence in patients with SKCM. The in vitro results revealed that the silencing of LSM2 in SKCM cells significantly inhibited cell proliferation, migration, and invasion.

CONCLUSION

Overall, LSM2 contributes to malignant status and poor prognosis in patients with SKCM and may be identified as a novel prognostic biomarker and therapeutic target.

The Association of Nevus-Associated Melanoma with Common or Dysplastic Melanocytic Nevus: A Systematic Review and Meta-Analysis

Background: Cutaneous melanoma has an adjacent nevus remnant upon histological examination in 30% of cases (nevus-associated melanoma, NAM), while it appears de novo for 70% of tumors. Regarding NAM arising in acquired melanocytic nevus, currently there is no evidence on whether NAM more frequently develops in association with a dysplastic or common melanocytic nevus. Objectives: To conduct a systematic review and meta-analysis to investigate the proportion of dysplastic or common melanocytic nevus in NAM associated with acquired nevus. Methods: A systematic literature search is conducted using PubMed, Scopus, and the Cochrane Library. The PRISMA checklist is used. Studies reporting patients diagnosed with NAM arising in an acquired common or dysplastic melanocytic nevus are included. A meta-analysis of proportions is performed using the random-effects model. The magnitude of heterogeneity is assessed with the I² statistic. Results: A total of 22 studies with 2174 NAMs with an acquired nevus (dysplastic or common) are included. The proportion of dysplastic nevus in NAM varies considerably in the included studies, ranging from 0% to 100%. In the meta-analysis, the overall estimate of the proportion of having a dysplastic nevus in NAM is 51% (95% CI: 39-63%) with high heterogeneity at I²: 95.8% (p < 0.01). A sensitivity meta-analysis of 12 studies that included 30 or more acquired nevus-NAMs (2023 cases) shows that 65% of the NAMs developed in a dysplastic nevus (95% CI: 51-77%). In a meta-analysis of 4 studies reporting invasive-only acquired nevus-NAMs (764 cases), the proportion of dysplastic nevus is 56% (95% CI: 36-75%). Only 2 studies are found reporting in situ NAMs with an acquired nevus, and the pooled estimated proportion of dysplastic nevus is 71% (95% CI: 63-78%). Conclusions: The results of this meta-analysis suggest a higher proportion of dysplastic nevus in acquired nevus-NAM; however, there is considerable uncertainty and high heterogeneity, highlighting the need for future well-designed studies with uniform histopathological definitions for dysplastic nevus remnants which report the type of nevus in NAM separately for invasive melanomas, thin tumors, and by histological subtype.

Melanocytic Lesions with Peripheral Globules: Proposal of an Integrated Management Algorithm

INTRODUCTION

A peripheral rim of globules represents a marker of the horizontal growth phase in nevi and is a common feature in children and adolescents. The observation of melanocytic lesions with peripheral globules (MLPGs) in adulthood deserves more attention, since melanoma may exhibit this feature, albeit rarely. Risk-stratified management recommendations considering a global clinical approach are still missing.

OBJECTIVES

To analyze current knowledge on MLPGs and propose an integrated management algorithm stratified for age groups.

METHODS

We conducted a narrative review of current published data on MLPGs, analyzing clinical dermoscopic and confocal distinguishing features of melanoma from benign nevi.

RESULTS

The risk of finding a melanoma when removing an MLPG increases with age, especially in people >55 years old, and is significantly higher in the extremities, head/neck and in case of a single asymmetrical lesion, ≥6 mm in diameter. Dermoscopic features associated with melanoma diagnosis include atypical peripheral globules, asymmetrical distribution, multiple rims as well as the reappearance of globules after prior loss. In addition, wide blue-grey regression areas, atypical networks, eccentric blotches, tan structureless peripheral areas and vascularization are atypical dermoscopic features. Confocal worrisome findings are represented by pagetoid cells within the epidermis, architectural disarrangement and atypical cells of the dermo-epidermal junction with irregular peripheral nests.

CONCLUSION

We proposed a multi-step age-stratified management algorithm integrating clinical, dermoscopic and confocal findings that may increase the early recognition of melanoma and avoid surgical excision of benign nevi.

Measurement instruments for the core outcome set of congenital melanocytic naevi and an assessment of the measurement properties according to COSMIN: a systematic review

Background

Congenital melanocytic naevi (CMN) can impact on patients' lives due to their appearance and the risk they carry of neurological complications or melanoma development. The development of a core outcome set (COS) will allow standardised reporting and enable comparison of outcomes. This will help to improve guidelines. In previous research, relevant stakeholders reached a consensus over which core outcomes should be measured in any future care or research. The next step of the COS development is to select the appropriate measurement instruments.

Aim

Step 1: to update a systematic review identifying all core outcomes and measurement instruments available for CMN. Step 2: to evaluate the measurement properties of the instruments for the core outcomes.

Methods

This study was registered in PROSPERO and performed according to the PRISMA checklist. Step 1 includes a literature search in EMBASE (Ovid), PubMed and the Cochrane Library to identify core outcomes and instruments previously used in research of CMN. Step 2 yields a systematic search for studies on the measurement properties of instruments that were either developed or validated for CMN, including a methodological quality assessment following the COSMIN methodology.

Results

Step 1 included twenty-nine studies. Step 2 yielded two studies, investigating two quality of life measurement instruments.

Conclusion

Step 1 provided an overview of outcomes and instruments used for CMN. Step 2 showed that additional research on measurement properties is needed to evaluate which instruments can be used for the COS of CMN. This study informs the instrument selection and/or development of new instruments.

A review of nevus-associated melanoma: What is the evidence?

Cutaneous melanoma may have an adjacent nevus remnant on histological examination in 30% of cases (nevus-associated melanoma, NAM), while it may appear de novo, without a precursor lesion, in the remaining 70% of cases. Nevus-associated melanoma and the concept of acquired melanocytic nevi serving as precursors of melanoma, has long been considered as a controversial topic. This controversy is, in part, due to their overall low rate of transformation to melanoma and scarce data on the natural history of progression. Another matter of debate regarded the possibility that the reported differences of NAM versus de novo melanoma, were due to an underestimation of NAM in thicker lesions due to obliteration of the nevus component by the tumour. During the last few years, several evidence has accumulated in order to address these controversies. In this review, we present a comprehensive synthesis of the epidemiological, clinical, dermoscopic and genetic findings in NAM, including thin NAM, compared to de novo melanoma. Answering the questions on nevus-associated melanoma may provide further insight on the classification of these tumours and disentangle their biology and route of development from that of de novo melanoma.

Spitzoid proliferative nodules arising in a congenital melanocytic naevus: A case report with clinical, dermoscopic and histologic correlation

Proliferative nodules (PNs) are benign nodular proliferation of melanocytes occurring within congenital melanocytic naevi (CMN). Differential diagnosis between PN and melanoma is challenging for clinicians and pathologists. We describe the case of a 9-month-old boy who developed multiple nodules arising in a medium-sized CMN. Clinically, pink papules were observed, with dotted vessels on dermoscopy, suggesting spitzoid PN. On histopathological examination, the dermoscopic findings correlated with the vertical vessels of a spitzoid PN. Dermoscopy could be a useful tool to differentiate PN from melanoma. However, further studies describing the dermoscopic features of the different PN subtypes are needed. Histopathology remains the gold standard for definitive diagnosis aided by ancillary molecular tests such as fluorescence in situ hybridization or comparative genomic hybridization.

Frequency of Publication of Dermoscopic Images in Inter-observer Studies: A Systematic Review

Research interest in dermoscopy is increasing, but the complete dermoscopic image sets used in inter-observer studies of skin tumours are not often shared in research publications. The aim of this systematic review was to analyse what proportion of images depicting skin tumours are published in studies investigating inter-observer variations in the assessment of dermoscopic features and/or patterns. Embase, MEDLINE and Scopus databases were screened for eligible studies published from inception to 2 July 2020. For included studies the proportion of lesion images presented in the papers and/or supplements was extracted. A total of 61 studies (53 original studies and 8 shorter reports (i.e. research letters or concise reports)). published in the period 1997 to 2020 were included. These studies combined included 14,124 skin tumours, of which 373 (3%) images were published. This systematic review highlights that the vast majority of images included in dermoscopy research are not published. Data sharing should be a requirement for future studies, and must be enabled and standardized by the dermatology research community and editorial offices.

Epidemiology and Risk Factors of Melanoma: A Review

We are currently witnessing a worldwide increase in the incidence of melanoma. Incidence in Europe is about 25 cases per 100,000 population, while in Australia it reaches a rate of 60 new cases per 100,000. While the epidemiological curves of the 1980's and 1990's suggested an increase in the incidence of melanoma across all age groups, the last 10 years' data indicates a 5% reduction in the incidence of thin melanoma in young individuals aged between 15 and 24. This suggests a positive impact of primary prevention campaigns [1-2]. The risk factors associated with melanoma are different and multifactorial: on one hand there is a genetic predisposition, as evidenced by the increased risk in patients with dysplastic nevus syndrome, with familial melanoma or familial melanoma syndromes; on the other hand, the unprotected interaction between UV rays and phototypes I-II increases the risk of developing melanoma, especially in case of sunburns in pediatric age. This review aims to summarize melanoma epidemiology and risk factors.

Dermoscopic Criteria, Histopathological Correlates and Genetic Findings of Thin Melanoma on Non-Volar Skin

Dermoscopy is a non-invasive, in vivo technique that allows the visualization of subsurface skin structures in the epidermis, at the dermoepidermal junction, and in the upper dermis. Dermoscopy brought a new dimension in evaluating melanocytic skin neoplasms (MSN) also representing a link between clinical and pathologic examination of any MSN. However, histopathology remains the gold standard in diagnosing MSN. Dermoscopic-pathologic correlation enhances the level of quality of MSN diagnosis and increases the level of confidence of pathologists. Melanoma is one of the most genetically predisposed among all cancers in humans. The genetic landscape of melanoma has been described in the last years but is still a field in continuous evolution. Melanoma genetic markers play a role not only in melanoma susceptibility, initiation, and progression but also in prognosis and therapeutic decisions. Several studies described the dermoscopic specific criteria and predictors for melanoma and their histopathologic correlates, but only a few studies investigated the correlation among dermoscopy, pathology, and genetic of MSN. The aim of this work is to review the published data about dermoscopic features of melanoma, their histopathological correlates with regards also to genetic alterations. Particularly, this review will focus on low-CSD (cumulative sun damage) melanoma or superficial spreading melanoma, high-CSD melanoma, and nevus-associated melanoma.

The differences in clinical and dermoscopic features between in situ and invasive nevus-associated melanomas and de novo melanomas

BACKGROUND

Nevus-associated melanomas (NAM) account for 30% of all melanomas and are associated with younger age and with thinner Breslow thickness. Previous studies of NAM dermoscopy found conflicting results.

OBJECTIVE

To compare the clinical and dermoscopic features of NAM and de novo melanomas (DNM), stratified by melanoma thickness, in a relatively large cohort of patients.

METHODS

A cross-sectional study of all melanomas biopsied between 2004 and 2019 at a large cancer centre. Lesions were categorized as in situ and invasive NAM or DNM. Dermoscopic images were reviewed and annotated. Associations between melanoma subtype and dermoscopic features were analysed via logistic regression modelling. Bivariate analyses were conducted using non-parametric bootstrap and chi-squared methods.

RESULTS

The study included 160 NAM (86 in situ and 74 invasive) and 218 DNM (109 in situ and 109 invasive). NAM were associated with younger age, greater likelihood of being present on the torso, and thinner Breslow thickness. NAM were 2.5 times more likely to show a negative pigment network than DNM. In situ NAM were 2.1 and two times more likely to display dermoscopic area without definable structures and tan structureless areas than DNM, respectively. In situ melanomas were more likely to present a pigment network, and invasive melanomas more commonly presented scar-like depigmentation and shiny white structures. Streaks, blotches and shiny white structures were associated with deeper Breslow depth.

CONCLUSIONS

Even though the nevus component of NAM could not be identified dermoscopically in the current series, negative pigment network, tan structureless areas and areas without definable structures are dermoscopic clues for NAM.