Frequency of Dermoscopic Nevus Subtypes by Age and Body Site

Abstract

Participants: Individuals older than 2 years undergoing total skin examination were consecutively recruited between October 1, 2008, and May 31, 2009, and, based on their age, assigned to 1 of 8 groups. For each patient, the location and dermoscopic pattern of all nevi on the torso were recorded. Nevi were dermoscopically subclassified as globular, reticular, mixed (reticularglobular) pattern with peripheral or central globules, or unspecified pattern. Main Outcome Measure: Frequency of dermoscopic nevus subtypes stratified by patient age and location of the nevi. Results: A total of 5481 nevi in 480 individuals were evaluated. The number of all nevus subgroups, except for unspecified pattern nevi, significantly increased before and decreased after the fourth decade of life. Globular nevi were most prevalent on the upper trunk in children and adolescents; the number decreased consistently after the second decade of life. The reticular pattern was the most common nevus pattern after the second decade of life and the most common nevus subgroup on the upper and middle back. Although uncommon, central globular nevi also showed an age-dependent trend, similar to that of reticular nevi. Nevi with the peripheral globular pattern declined rapidly after the third decade of life and were no longer observed after the sixth decade. The number of unspecified pattern nevi was stable across all age groups. Conclusion: Age, dermoscopic pattern, and location of nevi should be jointly considered when evaluating melanocytic lesions.

Wnt signaling potentiates nevogenesis

“…Specifically, Wnt signals that melanoblasts receive during their migration out of the neural crest may contribute to the delay of senescence and growth of nevi in utero (21)(22)(23). By extension, developmentally linked Wnt signals might contribute to preferential nevus formation in young children and adolescents (51,52), although other factors, such as declining telomere length, are also likely to be responsible for decreased proliferative potential and nevogenesis with age (13,52).…”

Distribution Analyses of Acquired Melanocytic Naevi on the Trunk

“…Previous studies have reviewed the prevalence and distribution of AMN on individual body sites [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24], even in larger BMI patients [25]. Some studies [6,7,12,15,16,17,18] have demonstrated a majority of naevi being present on the trunk compared to other body parts.…”

“…Some studies [6,7,12,15,16,17,18] have demonstrated a majority of naevi being present on the trunk compared to other body parts. However, no studies so far have described the continuous distribution of AMN on the trunk, typically opting to discuss the back or ventral trunk as discrete body sites.…”

“…Some studies have reviewed the site distribution of the various morphological subtypes of naevi [6,7]. Youl et al [8] described the distribution of both pigmented and non-pigmented benign and malignant lesions over the entire body.…”

“…Youl et al [8] described the distribution of both pigmented and non-pigmented benign and malignant lesions over the entire body. However, the clinical distribution of AMN on the adult trunk has not been thoroughly described despite the wealth of literature on this topic [6,7,8,9,10,11,12,13,14,15,16,17,18]. Therefore, in this study we investigated the relationship of naevi to their specific anatomical location on the trunk by creating a mathematical descriptor for the distance between the midline of the back and the exact position of a given naevus.…”