PIK3CA and thyroid tumor: The incidence of a BRAF p.V600E mutation in pediatric patients with PTC is lower and there is a lower risk for BRAF-associated widely invasive disease with decreased radioactive iodine avidity.5,12,13 In addition, coexisting mutations in the TERT promoter, TP53, and genes encoding effectors of the PI3K pathway (PIK3CA) are frequent in BRAF-mut (approximately 10%) and RET/NTRK (approximately 2.5%) advanced adult thyroid tumors.1 In our cohort of pediatric tumors screened by the CSTP panel (n = 66), we did not find any coexisting mutations in BRAF-mut or RET/NTRK tumors.