Cross‐sectional analysis of the dermoscopic patterns and structures of melanocytic naevi on the back and legs of adolescents. (27th October 2015)

• Record Type: Journal Article
• Authors: Fonseca, M.; Marchetti, M.A.; Chung, E.; Dusza, S.W.; Burnett, M.E.; Marghoob, A.A.; Geller, A.C.; Bishop, M.; Scope, A.; Halpern, A.C.
• Is Part Of: British journal of dermatology. Volume 173:Number 6(2015:Dec.)
• Page Start: 1486
• Page End: 1493
• Publication Date: 2015-10-27
• Subjects: Dermatology -- Periodicals; Skin -- Diseases -- Periodicals; 616.5
• DOI: 10.1111/bjd.14035
• Languages: English
• ISSNs: 0007-0963

Abstract

Summary: 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. Abstract : What's already known about this topic? Differences in the prevalence of melanocytic naevi by age and anatomical site have led to conflicting theories regarding naevogenesis. What does this study add? Dermoscopically defined globular and reticular acquired naevi show a distinct anatomical site distribution in adolescents. Globular naevi are significantly more likely to be found on the back than on the legs. Reticular naevi predominate on the legs compared with other dermoscopic patterns. Linked Comment: Finnane and Soyer, Br J Dermatol 2015; 173: 1367–68 .