Follicular thyroid cancer is a differentiated type of thyroid cancer, most of which progresses slowly and has a benign course, with a high 10-year survival rate and a very low mortality rate of over 95%. However, follicular cell carcinoma is also a differentiated type of thyroid cancer, and compared with papillary carcinoma, it is prone to invasion of extra-thyroidal vessels and distant metastasis, with relatively high recurrence rate and poor prognosis. Some patients may have distant metastasis, mainly along the blood stream, and need regular review and iodine-131 treatment if necessary, but the basis of iodine-131 treatment should be total thyroid excision.