Stage I follicular carcinoma is localized to the thyroid gland.

Follicular carcinoma tends to metastasize to lung and bone via the bloodstream.

Follicular carcinoma.

Hürthle cell carcinoma, a variant of follicular carcinoma with a poorer prognosis.

Follicular carcinoma invading cervical tissue has a worse prognosis than tumors confined to the thyroid gland.

Like follicular carcinoma, unilateral hemithyroidectomy is performed for non-invasive disease, and total thyroidectomy for invasive disease.

Done in case of follicular carcinoma of thyroid, medullary carcinoma of thyroid.

Hurthle cell forms are more likely than follicular carcinomas to be bilateral and multifocal and to metastasize to lymph nodes.

In addition, there is a presdisposition to breast carcinoma, follicular carcinoma of the thyroid, and endometrial carcinoma.

Follicular carcinoma and papillary carcinoma (often referred to as differentiated thyroid cancer) generally have a benign course, with a 10-year survival rate of more than 95%.

Features sine qua non for the diagnosis of follicular carcinoma are capsular invasion and vascular invasion by tumor cells.

Follicular carcinomas more commonly have blood vessel invasion and tend to metastasize hematogenously to the lungs and to the bone rather than through the lymphatic system.

The 10-year survival is better for patients with follicular carcinoma without vascular invasion than it is for patients with vascular invasion.

Mutations in this gene have been associated with thyroid dysgenesis, thyroid follicular carcinomas and atypical follicular thyroid adenomas.

Tollefsen HR, Shah JP, Huvos AG: Follicular carcinoma of the thyroid.

HBME-1 staining may be useful for differentiating papillary carcinomas from follicular carcinomas; in papillary lesions it tends to be positive.

I131: Studies have shown that a postoperative course of therapeutic (ablative) doses of I131 results in a decreased recurrence rate among high-risk patients with papillary and follicular carcinomas.

Stage IV is follicular carcinoma in patients older than 45 years with extension beyond the thyroid capsule to the soft tissues of the neck, cervical lymph node metastases, or distant metastases.

Hürthle cell carcinoma is a variant of follicular carcinoma with a similar prognosis and should be treated in the same way as equivalent stage non-Hürthle cell follicular carcinoma.

The role of external beam radiotherapy (EBRT) in thyroid cancer remains controversial and there is no level I evidence to recommend its use in the setting of differentiated thyroid cancers such as papillary and follicular carcinomas.

Stage III is follicular carcinoma in patients older than 45 years, larger than 4 cm and limited to the thyroid or with minimal extrathyroid extension, or positive lymph nodes limited to the pretracheal, paratracheal, or prelaryngeal/Delphian nodes.

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.

Stage II follicular carcinoma is defined as either tumor that has spread distantly in patients younger than 45 years, or tumor that is larger than 2 cm but 4 cm or smaller and is limited to the thyroid gland in patients older than 45 years.