The Morphologic Universe of Melanocytic Nevi

Can we manage the melanocytic lesions with peripheral globules according to the grade of dysplasia?

BACKGROUND/OBJECTIVES

Although excision of melanocytic nevi with high-grade dysplasia is recommended by the World Health Organization (WHO), clinical studies investigating the approach based on the grading dysplasia of melanocytic lesions with peripheral globules (PGs) are lacking. We investigated the grades of dysplasia and their distinguishable dermoscopic and clinical features to provide accurate data for managing these lesions.

METHODS

We retrospectively classified histologically confirmed melanocytic lesions with PGs according to the 2018 WHO Classification of Skin Tumours criteria in a university hospital in Turkey. Dermoscopic features, lesions, and patient characteristics were recorded.

RESULTS

Sixty-six lesions of 56 patients were included. After classification, 9.1% (n: 6) of lesions were melanomas, 39.4% (n: 26) were high-grade dysplastic nevi, and 50% (n: 33) were low-grade dysplastic nevi (n: 33, 50%). There was one nevus with no dysplasia (n: 1, 1.5%). Univariate analysis revealed that ≥31 years of age, irregular shape of peripheral globules, black colour, total colour count, and maximum diameter of the lesion were associated with high-grade dysplasia and melanoma. In the multivariate analyses, ≥31 years of age (OR = 3.80, 95% CI, 1.17-12.37), irregular shape of peripheral globules (OR = 3.90, 95% CI, 1.15-13.2), and total colour count (OR = 3.21, 95% CI, 1.2-8.5) were significant predictive factors for the lesions with high-grade dysplasia and melanomas.

CONCLUSIONS

To avoid the underdiagnosis of both melanomas and high-grade dysplastic nevi with PGs, the irregular shape of peripheral globules and multiple colours after the third decade may be useful in making an excision decision. The risk increases every 1-year increase in age. Excision is suggested for all melanocytic lesions with PGs for patients 60 years or older because of the high risk of melanoma and melanocytic nevus with high-grade dysplasia.

Nevus Variations in the Jordanian Population: Effects of Age, Medical Conditions, Environment, Congenital, Inherited, and Genetic Factors

Background

Nevi is a common benign proliferation of melanin-producing cells. Many triggers can influence their transformation into either benign or malignant, thus it is important to understand these triggers and their incidence across different populations to take adequate prevention. Here, we aim to examine the different etiologies of nevi changes across the Jordanian population.

Methods

We carried out a cross-sectional observational study focusing on patients seeking dermatological consultation for normal nevi or nevi with minimal changes. Demographic and clinical variables were collected from the patient's case history. Nevi's characteristics were also recorded. A skilled dermatologist assessed nevi morphology and changes using the ABCDE criteria for potential signs of melanoma. Nevi biopsy samples were fixed in formalin and sent for histopathological analysis and were stained with hematoxylin and eosin (H&E).

Results

A total of 231 patients were enrolled, with a majority of females (85%) and a median age of 37. Past medical history was positive in 17% of the samples, with hypertension, endocrine diseases, and diabetes mellitus being the most common. The majority of patients (61%) had fewer than three nevi. Changes in nevus size, configuration, and color were reported in 10% of patients, with multiple changes observed in 36% of patients. Microscopic analysis revealed polypoidal intradermal melanocytic blue nevi as the most common histopathological finding (84%). Positive medical history and the number of nevi were significantly associated with nevi changes.

Conclusion

Our results report that the number of nevi, as well as medical history, is linked to changes in their appearance. Additionally, we provide a detailed account of the various types of observed changes and their occurrence rates.

The Natural Evolution of Nevi with Peripheral Globules

BACKGROUND

Peripheral globules (PG) in melanocytic lesions represent a concerning dermoscopic feature since they might be present in growing nevi and melanomas. Their natural evolution has not been fully elucidated, and an age-based management approach has been recommended.

OBJECTIVES

The aim of this study was to calculate the growth rate of lesions with PG and investigate possible association with age, sex, location, and the global dermoscopic pattern.

METHODS

We retrospectively selected the lesions of interest from a cohort of Caucasian patients who underwent sequential digital dermoscopy monitoring. Lesions with PG distributed at 75% or more of their circumference with available follow-up images or histopathologic report were included. The surface area was automatically calculated with the help of an incorporated tool used in the acquisition of the images. The images were also evaluated by independent investigators for the presence of pre-defined criteria. Growth-curve models were used to assess the growth rate. The outcome variable was the area of nevi in mm2, and scatterplots with Lowess curves were used to present the mean change of nevi during follow-up.

RESULTS

A total of 208 lesions from 98 patients with a median age of 36 years (range 15-75) were included. The median follow-up time was 18 months (range 4-48). The mean growth rate for all nevi was 0.16 mm2/month (95% CI, 0.14-0.18, p < 0.001), ranging from -0.29 to 0.61 mm2/month. The growth rate was higher in nevi with a homogeneous dermoscopic pattern (p < 0.001). The number of peripheral globules during follow-up varied from increasing to complete disappearance. None of the lesions developed any melanoma-specific structure at follow-up.

CONCLUSION

Nevi with PG grew at a mean rate of 0.16 mm2/month, and the growth rate was independent of age, gender, or anatomic location. Nevi with homogeneous pattern demonstrated the highest growth rate in our cohort. None of the monitored nevi with PG developed melanoma-specific criteria at follow-up.

Lesion- and Patient-Related Variables May Provide Additional Clues during Dermoscopic Assessment of Blue Nevi—A Retrospective Cohort Study

Simple Summary

Blue nevi (BN) are dermal dendritic melanocytic proliferations which may be congenital or acquired. Due to wide clinical and dermoscopic presentation, their diagnosis may sometimes be difficult, especially if the history of lesion occurrence is unknown. Little is known about the correlation between lesion- and patient-related variables and dermoscopic features of blue nevi. The aim of the study was to analyze dermoscopic features of blue nevi, with particular regard to structures whose prevalence has not been previously reported, and to investigate the possible influence of selected clinical variables on dermoscopic presentation. Our findings provide new insights into the dermoscopic structures observed in blue nevi and their variability according to patient’s phototype and lesion size/localization.

Abstract

Background: Little is known about the correlation between lesion- and patient-related variables and the dermoscopic features of blue nevi. The aim of the study was dermoscopic analysis of blue nevi in association with patient- and lesion-related variables, with a special interest in structures whose prevalence has not been previously reported. Methods: This was a double-center, retrospective study, which included the analysis of histopathologically confirmed blue nevi (n = 93). Results: There was no difference in the frequency of the observed dermoscopic features according to patients’ gender and age. Pink structureless areas were more common in patients with I/II Fitzpatrick skin phototypes as well as in the patients with photodamaged skin, while blue prominent skin markings over brownish/blue-gray background occurred exclusively in patients with phototype III. Structures of previously unreported prevalence in blue nevi were skin-colored circles (present in 32.3%), gray circles (2.2%), follicular ostia with no pigmentation (18.4%; present exclusively on the face), blue skin markings over brownish background (present in 18.2%; detected only on the limbs) and dark brown polygons (one lesion located on the lower extremity). Conclusion: Dermoscopic presentation of blue nevi may vary according to the patient’s phototype and lesion size/localization rather than gender and age.

Are we born and do we die without nevi? A cross-sectional study

BACKGROUND

It is well known that the number of nevi varies with age. However, there are a few data in the literature concerning total nevus count at different ages. The aim of this study was to assess and compare the total nevus count among different age groups.

METHODS

The total nevus count was assessed in consecutive patients belonging to nine age groups. Median nevus count was calculated and compared for each age group. Multivariate logistic regression analysis was used to define the influence of sex and phototype on the association between nevus count and age.

RESULTS

We enrolled 900 patients (461, 51.2% females), with a median age of 46 years and a total of 18,136 nevi. Significant differences were found in the median total nevus count among all age groups (P < 0.001), with a significant increase in the first two decades and a significant decrease after the age of 50 years. A similar trend was also observed in subgroups. The differences observed in the total body nevus count among age groups were independent of sex and phototype.

CONCLUSIONS

We demonstrate that the total nevus count significantly increases during childhood and gradually decreases in the elderly.

Giant spotted grouped pigmented nevus: A case report

Spotted grouped pigmented nevus is a distinct form of non-giant congenital melanocytic nevi. Histopathologically, it tends to proliferate around the skin appendages. We report a case of a 10-year-old boy with clinical and pathological findings consistent with the diagnosis of spotted grouped pigmented nevus of more than 20 cm diameter, which is considered giant.

Dermatoscopy of combined blue nevi: a multicentre study of the International Dermoscopy Society

BACKGROUND

Combined blue nevi (CBN) may mimic melanoma and are relatively often biopsied for diagnostic reasons.

OBJECTIVE

To better characterize CBN and to compare it with melanoma.

METHODS

We collected clinical and dermatoscopic images of 111 histologically confirmed CBN and contrasted their dermatoscopic characteristics with 132 partly blue coloured melanomas. Furthermore, we compared the accuracy of human experts using pattern analysis with a computer algorithm based on deep learning.

RESULTS

Combined blue nevi are usually flat or slightly elevated and, in comparison with melanoma, more frequent on the head and neck. Dermatoscopically, they are typified by a blue structureless part in combination with either brown clods (n = 52, 46.8%), lines (n = 28, 25.2%) or skin-coloured or brown structureless areas (n = 31, 27.9%). In contrast with melanoma, the blue part of CBN is more often well defined (18.9% vs. 4.5%, P < 0.001) and more often located in the centre (22.5% vs. 5.3%, P < 0.001). Melanomas are more often chaotic (OR: 28.7, 95% CI: 14.8-55.7, P < 0.001), have at least one melanoma clue (OR: 10.8, 95% CI: 5.2-22.2 P < 0.001) in particular white lines (OR: 37.1, 95% CI: 13.4-102.9, P < 0.001). Using simplified pattern analysis (chaos and clues), two raters reached sensitivities of 93.9% (95% CI: 88.4-97.3%) and 92.4% (95% CI: 86.5-96.3%) at corresponding specificities of 59.5% (95% CI: 49.7-68.7%) and 65.8% (95% CI: 56.2-74.5%). The human accuracy with pattern analysis was on par with a state-of-the-art computer algorithm based on deep learning that achieved an area under the curve of (0.92, 95% CI: 0.87-0.96) and a specificity of 85.3% (95% CI: 76.5-91.7%) at a given sensitivity of 83.6% (95% CI: 72.5-91.5%).

CONCLUSION

CBN usually lack melanoma clues, in particular white lines. The accuracy of pattern analysis for combined nevi is acceptable, and histopathologic confirmation may not be necessary in exemplary cases.

A descriptive observational study on clinical and dermoscopic features of benign melanocytic neoplasms

Background

Benign melanocytic neoplasms have nests of melanocytic cells and show characteristic dermoscopic features. Clinical and dermoscopic features have not been studied previously in the Indian population.

Aims

To study the clinical, epidemiological and dermoscopic patterns of benign melanocytic neoplasms.

Methods

This was a descriptive, observational, single centre study. In 107 patients with melanocytic neoplasms, 167 lesions were clinically examined and studied under the dermoscope and histopathological examination was done when indicated. The lesions were broadly divided as acquired and congenital. Five main dermoscopic patterns were seen-globular, homogenous, reticular, parallel and streaks. If there were two of these patterns in a particular lesion, it was termed 'mixed pattern'. The presence of three or more patterns was called 'multicomponent pattern'. Various other features were also observed.

Results

The majority of patients belonged to the third decade with a female preponderance. History of increased UV exposure and family history was significant in acquired nevi. The dermoscopic pattern progressed from predominantly reticular in junctional nevi to predominantly globular in compound nevi and lesser pigment in intradermal nevi, with more vascular structures. The congenital melanocytic nevi showed additional features of comedo- like lesions, milia- like cysts, perifollicular pigmentary changes and increased colour variation. Even though colour variation was observed in both acquired and congenital lesions, no signs of dysplasia were seen on histopathology.

Limitations

A larger sample size is required, with follow up of lesions. No parallel studies in brown skinned population were found for exact comparison.

Conclusion

Benign melanocytic proliferations are often neglected in our country. This study will help in understanding the course, clinical features and dermoscopic patterns of various benign melanocytic neoplasms, and will be a step forward towards research in our population. To the best of our knowledge, this is the first study of its kind in India.

Dermatoscopic Features of Combined nevus – a Case Report

Combined nevi (CN), a rare nevus type represent a category of so-called compound tumors. Determined by the presence of two or more different nevus in one biopsy specimen, CN commonly show variable clinical and dermatoscopic features. Therefore, CN could be a diagnostic challenge. We present a 7-year-old Caucasian girl with a pigmented lesion on the arm of no specified duration. Clinical examination showed sharply demarcated pigmented papule. Dermatoscopy revealed a nonchaotic lesion with structureless well defined, minimally eccentric blue area, structureless brown area and brown clods in a symmetric fashion, no vessels and no other clues for melanoma. Histopathology showed a compound common melanocytic nevus, blue nevus in the centre of the lesion with no signs of atypia. Up to now, only 25 cases of CN with dermatoscopic description have been published, withno precise dermatoscopic features established yet. Therefore, studies with larger number of cases are needed for the final conclusions.

BAP1 tumor predisposition syndrome case report: pathological and clinical aspects of BAP1-inactivated melanocytic tumors (BIMTs), including dermoscopy and confocal microscopy

BACKGROUND

BRCA1 associated-protein 1 (BAP1) tumor predisposition syndrome is associated with an increased risk for malignant mesotheliomas, uveal and cutaneous melanomas, renal cell carcinomas, and singular cutaneous lesions. The latter are referred to as BAP1-inactivated melanocytic tumors (BIMTs). When multiple BIMTs manifest, they are considered potential markers of germline BAP1 mutations.

CASE PRESENTATION

Here, we report a novel pathogenic BAP1 germline variant in a family with a history of BIMTs, cutaneous melanomas, and mesotheliomas. We also describe singular pathological aspects of the patient's BIMT lesions and their correlation with dermoscopic and reflectance confocal microscopy findings.

CONCLUSIONS

This knowledge is crucial for the recognition of BIMTs by dermatologists and pathologists, allowing the determination of appropriate management for high-risk patients, such as genetic investigations and screening for potentially aggressive tumors.

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.

Abundance of the benign melanocytic universe: Dermoscopic-histopathological correlation in nevi

The broad universe of "melanocytic nevi" includes a variety of different subtypes, which can be classified either due to their morphology, epidemiology, genetic alterations or risk for developing melanoma. Regarding morphology, on the one hand macroscopic/clinical and on the other hand histopathological appearance were used to subdivide in the past, often resulting in confusion and poor interobserver agreement, while nowadays dermoscopy presents the clinician's precious bridge between naked-eye examination and histopathological diagnostics, allowing prediction of the lesions' histopathology, follow up and monitoring over time without need of excision. The non-invasive dermoscopic examination relies on the assessment of colors, patterns and the distribution of both within a cutaneous lesion. Until today, the correspondence of certain dermoscopic colors and patterns to certain histopathological correlates has been reported for a huge amount of different cutaneous lesions. Moreover, the correspondence of certain dermoscopic features to certain body sites, age groups and pigmentary traits, but also to specific genetic alterations in lesions, has been broadly investigated. Dermoscopy has led us to a new understanding of melanocytic nevi's biology and evolution and, last but not least, to a new classification system, which we want to present herein.

Dermoscopic and Immunohistochemical Changes in Acquired Melanocytic Nevi following Narrow-Band Ultraviolet B Therapy

BACKGROUND

Acquired melanocytic nevi (AMN) have been reported to undergo morphological and dermoscopic changes following exposure to narrow-band ultraviolet B (NB-UVB) radiation.

OBJECTIVE

To study the morphological, dermoscopic and immunohistochemical changes in AMN following NB-UVB radiation.

METHODS

Suberythemogenic NB-UVB sessions were delivered to 40 patients with AMN. For each patient, a minimum of 2 nevi were selected. One nevus was surgically removed from each patient prior to sessions as control; for the other nevus, dermoscopic images were captured before and after NB-UVB sessions. The images were evaluated for changes. At the end, another nevus was surgically removed for immunohistochemical assessment of Ki-67 and melan-A.

RESULTS

Our study showed a statistically significant increase in the size of AMN following NB-UVB radiation. Benign dermoscopic changes were observed. Statistically significant positive correlations were found between some dermoscopic findings and the total cumulative dose of NB-UVB. Immunohistochemical analysis did not show any significant change in the exposed AMN.

CONCLUSION

AMN irradiated with repeated suberythemogenic doses of NB-UVB showed benign morphological and dermoscopic changes, and this was confirmed by our immunohistochemical study.

Growth-Curve Modeling of Nevi With a Peripheral Globular Pattern

Importance

Although nevi with a peripheral rim of globules (peripheral globular nevi [PGN]) observed with dermoscopy are associated with enlarging melanocytic nevi, their actual growth dynamics remain unknown. Because change is a sensitive but nonspecific marker for melanoma, beginning to understand the growth patterns of nevi may improve the ability of physicians to differentiate normal from abnormal growth and reduce unnecessary biopsies.

Objective

To study the growth dynamics and morphologic evolution of PGN on dermoscopy.

Design, Setting, and Participants

A total of 84 participants with 121 PGN from September 1, 1999, through May 1, 2013, were identified retrospectively. Cohorts were recruited from the Memorial Sloan Kettering Cancer Center; Melanoma Unit of the Hospital Clinic, University of Barcelona; and Study of Nevi in Children. All 3 cohorts underwent longitudinal monitoring with serial dermoscopic imaging of their PGN. Data analysis was performed from May 1, 2014, through April 1, 2015.

Main Outcomes and Measures

Establishment of the natural growth curve of PGN. The secondary aim was to establish the median time to growth cessation in those PGN for which the size eventually stabilized and/or had begun to decrease during the study period.

Results

The median duration of follow-up was 25.1 (range, 2.0-114.4) months. Most of the nevi (116 [95.9%]) enlarged at some point during sequential monitoring. The rate of increase in the surface area of PGN varied among cohorts and ranged from -0.47 to 2.26 mm2/mo (mean rate, 0.25 [95% CI, 0.14-0.36] mm2/mo). The median time to growth cessation in the 26 PGN that stabilized or decreased in size (21.5%) was 58.6 months. All lesions changed in a symmetric manner and 91 (75.2%) displayed a decrease in the density of peripheral globules over time.

Conclusions and Relevance

Nevi displaying a peripheral globular pattern enlarged symmetrically with apparent growth cessation occurring during a span of 4 to 5 years. Our results reiterate the important concept that not all growth is associated with malignancy.

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

BACKGROUND

Junctional (flat) naevi predominate on the extremities, whereas dermal (raised) naevi are found primarily on the head, neck and trunk. Few studies have investigated the anatomical site prevalence of melanocytic naevi categorized using dermoscopy.

OBJECTIVES

To identify the prevalence of dermoscopic patterns and structures of naevi from the back and legs of adolescents.

METHODS

Dermoscopic images of acquired melanocytic naevi were obtained from the back and legs of students from a population-based cohort in Framingham, Massachusetts. Naevi were classified into reticular, globular, homogeneous or complex dermoscopic patterns. Multinomial logistic regression modelling assessed the associations between dermoscopic pattern and anatomical location.

RESULTS

In total 509 participants (mean age 14 years) contributed 2320 back naevi and 637 leg naevi. Compared with homogeneous naevi, globular and complex naevi were more commonly observed on the back than the legs [odds ratio (OR) 29·39, 95% confidence interval (CI) 9·53-90·65, P < 0·001 and OR 6·8, 95% CI 2·7-17·14, P < 0·001, respectively], whereas reticular lesions were less likely to be observed on the back than on the legs (OR 0·67, 95% CI 0·54-0·84, P = 0·001). Naevi containing any globules were more prevalent on the back than on the legs (25% vs. 3·6%, P < 0·001). Naevi containing any network were more prevalent on the legs than on the back (56% vs. 40·6%, P < 0·001).

CONCLUSIONS

These findings add to a robust body of literature suggesting that dermoscopically defined globular and reticular naevi represent biologically distinct naevus subsets that differ in histopathological growth pattern, age- and anatomical-site-related prevalence, molecular phenotype and aetiological pathways.

The most common mistakes on dermatoscopy of melanocytic lesions

Dermatoscopy is a method of in vivo evaluation of the structures within the epidermis and dermis. Currently, it may be the most precise pre-surgical method of diagnosing melanocytic lesions. Diagnostic errors may result in unnecessary removal of benign lesions or what is even worse, they can cause early and very early melanomas to be overlooked. Errors in assessment of dermatoscopy can be divided into those arising from failure to maintain proper test procedures (procedural and technical errors) and knowledge based mistakes related to the lack of sufficient familiarity and experience in dermatoscopy. The article discusses the most common mistakes made by beginner or inexperienced dermatoscopists.

Dermoscopy of accessory nipples in authors' own study

Introduction

The accessory nipple (AN) is characterised by its network-like structures, which may suggest the diagnosis of a melanocytic lesion. The knowledge about additional dermoscopic features of AN may greatly minimise the risk of unnecessary surgical excisions.

Aim

To analyse and present different clinical and dermoscopic forms, in which the AN may appear.

Material and methods

Ninety AN with dermoscopic features were evaluated in the study, detected in 14 patients between the years 2008 and 2014.

Results

The most common dermoscopic features of the AN were central, scar-like areas (15/19) and peripheral network-like structures (12/19). A number of cleft-like appearances (8/19) and central network-like structures (7/19) had also been observed. Moreover, among the dermoscopic features, white cobblestone-like structures (7/19), a central round dimpling with a plug (6/19) and fisheye-like structures resembling comedo-like openings (9/19) have all also been noted. There is a statistical significance in the occurrence of white cobblestone-like structures with central network-like structures (Fisher's exact test p = 0.0449). The presence of peripheral network-like structures with the occurrence of central scar-like areas was statistically highly significant (p = 0.0091). The central round dimpling was never observed alongside any central network-like structures in any of the lesions (p = 0.0436).

Conclusions

Accessory nipples are most commonly characterised by the occurrence of a peripheral network-like structure accompanied by the presence of a scar-like area.

Mechanical properties of growing melanocytic nevi and the progression to melanoma

Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma in a way that is still unclear from the biochemical and genetic point of view. Diagnostic and prognostic tools are then mostly based on dermoscopic examination and morphological analysis of histological tissues. To investigate the role of mechanics and geometry in the morpholgical dynamics of melanocytic nevi, we study a computation model for cell proliferation in a layered non-linear elastic tissue. Numerical simulations suggest that the morphology of the nevus is correlated to the initial location of the proliferating cell starting the growth process and to the mechanical properties of the tissue. Our results also support that melanocytes are subject to compressive stresses that fluctuate widely in the nevus and depend on the growth stage. Numerical simulations of cells in the epidermis releasing matrix metalloproteinases display an accelerated invasion of the dermis by destroying the basal membrane. Moreover, we suggest experimentally that osmotic stress and collagen inhibit growth in primary melanoma cells while the effect is much weaker in metastatic cells. Knowing that morphological features of nevi might also reflect geometry and mechanics rather than malignancy could be relevant for diagnostic purposes.

Melanocytic nevi in children of southern Italy: dermoscopic, constitutional, and environmental factors

The objective was to estimate the prevalence of melanocytic nevi (MN) in children and to determine their dermoscopic characteristics and relationship with anatomic location and environmental and constitutional factors. The population was a randomly selected sample of 144 children who attended primary schools in Naples, Italy. Before physical examination of the children, standardized interviews were conducted with their parents. Follow-up interviews of both the children and parents were conducted 1 year later. Photographic and dermoscopic images were obtained. Boys had more MN than girls; 465 MN (55.6%) were observed in boys and 371 (44.4%) in girls (p < 0.05). The trunk and neck were the most common locations of MN (p < 0.001). The main dermoscopic feature of all MN observed was a globular pattern (p < 0.001). A significant correlation between duration of sunbathing and MN counts was revealed (p < 0.05). At 1-year follow-up, 118 new MN were identified in 66 children. The trunk and neck areas were the most common regions involved in the appearance of new MN (n = 68, 57.6% of all new MN, p < 0.001). The new MN count was significantly higher in children who reported more sunbathing (p < 0.001). Changes in the dermoscopic pattern were observed in 45 persistent MN, demonstrating more MN with a reticular-globular pattern, especially on the trunk, neck, and upper extremities (p < 0.001). MN development in early life is the result of complicated relationships between nevus evolution, anatomic location, and environmental and constitutional factors.

Dermoscopic patterns of cutaneous melanoma metastases

In 2-8% of patients with melanoma, the first clinical manifestation of the disease may be skin metastasis. In these cases, differential diagnosis with the primary melanoma, benign melanocytic lesions, and other malignant and benign skin growths is particularly challenging. For this reason, the dermatologist's approach to cutaneous metastases of malignant melanoma calls for knowledge of the great morphological variety of these lesions. Dermoscopic characteristics associated with CMMMs have not yet been codified. The aim of the present review is to provide additional information about dermoscopic aspects of these skin lesions.