Advances in Follicular Thyroid Cancer Diagnosis and Management.

Follicular thyroid cancer is an uncommon well-differentiated thyroid cancer with a wide spectrum of behavior, ranging from indolent minimally invasive tumors to extensive angioinvasive tumors with distant metastasis. While often grouped with papillary thyroid carcinoma, it has distinct molecular, sonographic, histologic, and clinical features. Diagnosis cannot be made by biopsy and requires diagnostic surgery. Distinction between follicular thyroid carcinoma and other follicularly-patterned tumors has evolved, generating controversy and contradictory literature. Management is risk-adapted: lobectomy is appropriate for localized tumors, while high-risk cancers require total thyroidectomy, thyroid stimulating hormone suppression, radioactive iodine, and ablative or systemic therapies.