Abstract

Pigmented lesions in children present a diagnostic challenge given their morphologic characteristics and tendency to evolve.  We analyzed skin biopsies of pigmented lesions in children performed by our pediatric dermatology division from 2017-2022. Biopsies were included for all patients 18 years old and younger if the biopsy revealed a melanocytic neoplasm. The final cohort was comprised of 254 biopsies from 218 unique patients aged 10 months to 18 years old.  130 patients self-identified as male and 124 as female.  Biopsies were performed more frequently in adolescents than in younger children.  The most common histopathologic diagnoses rendered were compound melanocytic nevus (CMN, n=111), intradermal nevus (IDN, n=58), Spitz nevus (n=24), blue nevus (n=11) and beta-catenin-activated melanocytoma (also known as deep penetrating melanocytoma, n=11).  Seven atypical Spitz tumors (AST) were diagnosed in children aged 3-13 years.  Intermediate grade lesions (AST and melanocytomas) were diagnosed from 23% of biopsies in children 5 years old and younger, 13% of biopsies in 6-11 year olds, and 4% of biopsies in 12-18 year olds.  No melanomas were identified.  The most common indications for biopsy were clinically concerning appearance (n=95), irritation (n=64), evolution (n=45), and patient/parental preference (n=23).  Irritation was the most common indication for biopsies of intertriginous areas and scalp.  Among lesions biopsied for patient/parental preference, 100% were banal CMN or IDN.  In conclusion, melanocytic lesions were biopsied in children of all ages for various indications; intermediate grade lesions were more common in young children and no melanomas were identified in this cohort.