RESUMO
ABSTARCT Purpose To investigate the clinicopathologic characteristics and genetic mutations of metastatic follicular thy-roid carcinoma(FTC).Methods A total of 22 cases of meta-static FTC were collected,including previous medical history,imaging,treatments and outcomes,and next-generation sequen-cing study and Sanger sequencing were performed in 12 cases.Results There were 16 women and 6 men.Sixteen cases were older than 50 years.Seven cases presented with metastases as the first symptom.Fourteen cases developed metastases 3 to 12 years after thyroid surgery.Sixteen cases developed bone metas-tasis,10 cases had lung metastasis,and 3 cases had brain me-tastasis.Those patients with multiple bone metastases progressed during the follow-up period.The common gene mutations in me-tastases were NRAS p.Q61R(6 cases),HRAS p.Q61R(2 ca-ses)and KRAS p.Q61R(1 case),followed by TERT promoter mutation(8 cases).Other mutated genes included KEL,BRCA1/2,ALK,ROS1,ErbB4,etc.Conclusion FTC has a high misdiagnosis rate.Those diagnosed with FTC should under-go regular systemic examinations to detect potential metastasis,especially in bone,lung,and brain.Further research on the sig-nificance of NRAS and other molecular indicators in FTC metas-tasis will help to better predict its biological behaviors.