A previously healthy 12-yr-old boy presented with a painless right neck mass without constitutional symptoms, no family history of cancer...total thyroidectomy confirmed PTC...sequencing data results revealed a somatic TPM3::NTRK1 fusion...high NTRK1 expression...PDGFRB and EGFR also show high percentile...GLI1, GLI2, and GLI3 all show high level of expression...The patient was enrolled on a pediatric phase I/II study (NCT02637687) evaluating an oral, selective pan-TRK inhibitor, larotrectinib. Following two cycles of TRK inhibitor therapy, repeat CT chest demonstrated an overall reduction in number of pulmonary nodules.