Follicular thyroid cancer is the second most common thyroid malignancy
. Dietary iodine content may determine the relative proportion of foll
icular thyroid cancer and papillary thyroid cancer. Several subgroups
of follicular thyroid cancer, which may show some differences in clini
cal behavior, can be recognized histologically. Primary treatment of f
ollicular thyroid cancer is complete surgical removal of tumor, usuall
y followed by suppressive thyroid hormone therapy. High-risk patients
may also undergo radioiodine remnant ablation. The prognosis for young
patients with small, minimally invasive tumors is excellent, whereas
older patients with more extensive tumors or distant metastases at pre
sentation may suffer substantial morbidity and mortality. Follow-up sh
ould be most intense during the first 5 years after the initial surger
y and involves serum thyroglobulin measurements and, for some patients
, diagnostic radioiodine scanning.