Like follicular carcinoma, unilateral hemithyroidectomy is performed for non-invasive disease, and total thyroidectomy for invasive disease. Diagnosis
It is difficult to correctly diagnose follicular neoplasms (FNs) on fine-needle aspiration cytology (FNAC) because it shares many cytological features with other mimicking lesions. Classification
It is impossible to distinguish between follicular adenoma and  carcinoma on cytological grounds. If fine needle aspiration cytology (FNAC) suggests follicular neoplasm, thyroid lobectomy should be performed to establish the histopathological diagnosis. Features sine qua non for the diagnosis of follicular carcinoma are capsular invasion and vascular invasion by tumor cells. Still, focuses of the capsular invasion should be carefully evaluated and discriminated from the capsular rupture due to FNA penetration resulting in WHAFFT (worrisome histologic alterations following FNA of thyroid). Follicular carcinoma tends to metastasize to lung and bone via the bloodstream. Papillary thyroid carcinoma commonly metastasizes to cervical lymph nodes.HMGA2 has been proposed as a marker to identify malignant tumors. Treatment
Treatment is usually surgical, followed by radioiodine. Initial treatment
If follicular cells are found on cytological testing, it is common to carry out hemithyroidectomy to distinguish between follicular adenoma and follicular carcinoma on histopathological examination, proceeding to completion thyroidectomy and postoperative radioiodine ablation where carcinoma is confirmed. This way total thyroidectomy is not carried out unnecessarily. Thyroidectomy is invariably followed by radioiodine treatment at levels from 50 to 200 millicuries following two weeks of a low iodine diet (LID). Occasionally treatment must be repeated if annual scans indicate remaining cancerous tissue.
Prognosis
The overall 5-year survival rate for follicular thyroid cancer is 91%, and the 10-year survival rate is 85%.By overall cancer staging into stages I to IV, follicular thyroid cancer has a 5-year survival rate of 100% for stages I and II, 71% for stage III, and 50% for stage IV.Compared to other variants of Follicular cell derived thyroid cancer, bone metastases are commonly associated with follicular carcinoma. In the present study a high rate of bone metastases of 34% was observed. References
External links

Thyroid cancer at DMOZ Archived 2017-03-14 at the Wayback Machine
Cancer Management Handbook: Thyroid and Parathyroid Cancers
Management Guidelines for Patients with Thyroid Nodules and Differentiated Thyroid Cancer The American Thyroid Association Guidelines Taskforce (2015).