Abstract: Thyroid cancer is the most common endocrine malignancy.This report describes a rare case of giant follicular thyroid carcinoma (FTC) in a patient presenting with hyperthyroidism and multiple metastases involving the lungs,bones,and mediastinal lymph nodes.Such a presentation is extremely uncommon in FTC cases.The patient's treatment primarily involved surgery supplemented by radioactive iodine therapy and targeted therapy.The clinical course was complex,and therapeutic outcomes were limited.This case aims to provide diagnostic and therapeutic insights and offer relevant references for future research on such rare cases.

Key words: follicular thyroid carcinoma;tumor-associated hyperthyroidism;multiple metastases;targeted therapy;treatment efficacy