Evaluation of the molecular landscape of pediatric thyroid nodules and use of a multigene genomic classifier in children

Brief summary: In 2021 and 2022, two important publications on pediatric thyroid carcinomas revealed a distinct molecular landscape compared to adult thyroid carcinomas (1,2). Pediatric differentiated thyroid carcinoma was mainly caused by fusion oncogenes, especially in children younger than 10 years (93%), compared to children aged 10–15 years (28%) and 15–20 years old patients (14%). In contrast, PTC due to BRAF mutations showed increasing frequency with age (7%, 30%, and 65%, respectively in children <10 years, 10–15 years, and 15–20 years. The major clinical consequence of these results was that pediatric thyroid carcinomas caused by fusion oncogenes could successfully be treated with fusion targeted therapies in patients after molecular diagnosis (1). These results were confirmed in a second large study (2).