The melanocytic nevi are both well-known risk factors and mimickers of melanoma.1–3 During the last three decades, the clinical features and anatomical distribution patterns of nevi in the pediatric age group and their association with demographic, constitutional, and environmental factors were widely investigated.4–12

Following the advent of dermoscopy into the routine clinical practice, increasing reports on dermoscopic features of nevi during childhood and adolescence, the most active periods in terms of nevus development,13 have created a basic knowledge.3,14–25 In order to understand the concept of nevogenesis, special effort has been invested in age-related dermoscopic patterns of melanocytic nevi.3,14–25

Being familiar with the benign dermoscopic patterns would guide proper clinical management of nevi, ease early diagnosis of melanoma, and avoid unnecessary biopsies performed to rule out malignancies.13,15,19 However, the studies mainly belong to pediatric populations from Europe, Australia, and America, preventing the generalization of the findings to different geographical regions.17

The aim of this study was to assess the clinical and dermoscopic features of acquired melanocytic nevi in Turkish children and adolescents and investigate the influence of demographic, constitutional, and environmental factors on these lesions.

In this cross-sectional, single-center study, patients aged < 18 years admitted to the dermatology outpatient clinic of our tertiary referral center in the Western Turkey region were invited for melanocytic nevi examination with the consent of their legal guardians between January and June 2023. Patients with at least one lesion of any size compatible with melanocytic nevus both clinically and dermoscopically were consecutively enrolled in the study. Patients with a history of prolonged solar exposure four weeks prior to the examination, nevi of the nail unit, genital or mucosal region, congenital nevi diagnosed based on the morphology and presence during the first year of life, suspicious lesions necessitating biopsy to exclude malignancy, and special nevi such as Spitz nevus, agminated nevus, halo nevus or blue nevus were excluded.

The verbal and written consents were gathered from the legal guardians of the participants. Demographic findings (gender, age), personal and family history of skin cancer, sun protection practices by means of sunscreen use, and history of sunburn (in terms of number and severity [mild-moderate or severe characterized by the presence of erythema or painful blisters, respectively]) were recorded.

Participants were evaluated in two age groups: children (patients aged ≤ 10-years) and adolescents (patients aged > 10-years). They were examined regarding their eye and hair color. Skin phototype was assessed according to the Fitzpatrick scale.26

Melanocytic nevi were examined in terms of number, size (diameter), and anatomical region. The dermoscopic evaluation of melanocytic nevi was first performed with a hand-held dermatoscope (DermLite DL4®, 3Gen, California, USA), followed by the documentation with a digital camera (Canon EOS 5D®, Canon Inc., Tokyo, Japan) attached to a dermatoscopic lens (DermLite FOTO II Pro®, 3Gen, California, USA). Three dermatologists evaluated the lesions independently.

Dermoscopic patterns were categorized into four major groups27: globular, reticular, homogeneous, and complex (Fig. 1), the latter being a combination of globular, reticular or homogeneous patterns,28 comprising globular-reticular, globular-homogeneous, and reticular-homogeneous. For each individual, the pattern observed in more than 40% of melanocytic nevi was accepted as the predominant dermoscopic pattern.27 The individuals not complying with this criterion were assigned to have an unspecified pattern. The nevi on the scalp and acral sites were only included in the total nevus count but evaluated separately in terms of dermoscopic features while determining the predominant dermoscopic pattern.

Figure 1.

Nevi of the participants exhibiting four major dermoscopic patterns: (A) Globular, (B) Reticular, (C) Homogeneous, and (D) Complex.

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IBM SPSS® Statistics Version 26 was used to store and analyze the data. Shapiro-Wilk test was used to evaluate the normality of variable distribution. Descriptive statistics were calculated as mean ± standard deviation and median [minimum‒maximum] values for continuous variables and as frequency and percentage for categorical variables. The Chi-Square test or Fisher’s exact test was used to assess the differences in the distribution of categorical variables between two independent groups. The Mann-Whitney U test was used for the comparison of non-normally distributed groups. The p-value less than 0.05 was considered statistically significant.

The study has been approved by the institutional ethical committee (approval number: 2022/14-24) and conducted in accordance with the Declaration of Helsinki.

A total of 574 acquired melanocytic nevi of 100 participants were evaluated. The demographic and phenotypical characteristics of the study population are summarized in Table 1. The study group consisted of 50 females and 50 males with median ages of 9.5 and 11.5 years, respectively (p = 0.41). The median age and the distributions of gender and skin phototype were similar in both groups who used sunscreen and those who never used it (Table 2).

A significantly higher median number of melanocytic nevi was detected in adolescents compared to children (6 vs. 4; p < 0.05). On the other hand, the median nevi number did not show any difference regarding gender (female 4.5 vs. male 4; p = 0.424), skin phototype (type I‒II 5 vs. type III‒IV 4; p = 0.155) or sunscreen use (present 4 vs. not present 5; p = 0.345).

The upper extremities were the most common anatomical region harboring melanocytic nevi in 68 participants, followed by the trunk (n = 67) and face (n = 50) (Table 3). The prevalence of melanocytic nevi on the upper extremities was significantly higher in females than in males [80% (n = 40/50) vs. 56% (n = 28/50); p < 0.05]. The trunk was involved more frequently in males, albeit with no statistical significance (Table 4).

The globular pattern was the most frequent predominant dermoscopic pattern (n = 57) (Fig. 1a) (Table 1). In 13 patients, no specific dermoscopic pattern predominated, while complex patterns were detected in the majority of nevi in 10 patients [globular-reticular (n = 7) and globular-homogeneous (n = 3)].

Even though both age groups had a globular pattern as the major predominant dermoscopic pattern, adolescents showed a significantly lower rate of this pattern than children (Fig. 2). On the other hand, a remarkable increase in the reticular pattern was noted in adolescents (Fig. 2). No difference in the predominant dermoscopic pattern was observed concerning gender, skin phototype, or sunscreen use (Table 5).

Figure 2.

Comparison of the rates of predominant dermoscopic patterns in children and adolescents (Chi-Square test).

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Globular pattern was the main dermoscopic pattern in any anatomical location except lower extremities where homogeneous pattern predominated (Table 3). Additionally, the globular and homogeneous patterns detected in participants with facial nevi were accompanied by a pseudo-network pattern in 86% (n = 43/50) of these individuals.

The evidence on the clinical and dermoscopic characteristics of melanocytic nevi in the young population is growing.3–25 However, it is still challenging to compare these studies due to differences in age groups and skin phototypes of participants, the frequency and degree of solar exposure depending on the geographical region where the study was conducted. Furthermore, some studies only included nevi from specific anatomical sites, such as the back,21,23 as some examined lesions larger than 2 mm in diameter only.9,22

In conclusion, nevogenesis is a complex process due to the significant interplay between genetic and environmental factors. The age and anatomical site were the most relevant factors influencing the number and dermoscopic patterns of nevi in our study. The predominance of globular pattern in childhood and the increasing rate of reticular pattern in adolescence support the dual concept of nevogenesis.34 The dermoscopic patterns differing in terms of anatomical sites also confirm the presence of distinct developmental pathways. The gender-related distribution pattern of nevi, without any effect of sunscreen use on either nevus count or dermoscopic pattern, further suggests a genetic predisposition.

None declared.

Zeynep Keskinkaya: The study concept and design, data collection, analysis and interpretation, statistical analysis, writing of the manuscript, critical review of important intellectual content, effective participation in the research guidance, intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases, critical review of the literature, final approval of the final version of the manuscript.

Özge Kaya: The study concept and design, analysis and interpretation of data, writing of the manuscript, critical review of important intellectual content, intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases, final approval of the final version of the manuscript.

Selda Işık Mermutlu: The study concept and design, analysis and interpretation of data, writing of the manuscript, critical review of important intellectual content, intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases, final approval of the final version of the manuscript.

Hilay Garipcan Karaemir: The study concept and design, data collection, analysis and interpretation, writing of the manuscript, critical review of important intellectual content, intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases, final approval of the final version of the manuscript.

Sevilay Oğuz Kılıç: The study concept and design, analysis and interpretation of data, writing of the manuscript, critical review of important intellectual content, intellectual participation in the propaedeutic and/or therapeutic conduct of the studied cases, final approval of the final version of the manuscript.

None declared.