Thyroid nodules: pathogenesis, diagnosis and treatment

Thyroid nodules are very frequently found and their prevalence steadily increases with age. The discovery of such lesions by high-resolution radiological imaging procedures that have been performed for other indications raises the problem of how incidentally discovered thyroid nodules should be investigated in a cost-effective manner to identify the rare patient with a clinically significant malignancy. In this review the clinical criteria that prompt the evaluation of thyroid nodules are discussed, as is the currently recommended diagnostic approach, which principally relies on fine needle aspiration biopsy. The clinical implications of the different cytological diagnoses are discussed, with a special emphasis on the management of indeterminate, microfollicular lesions. Finally, the evidence for and against suppressive thyroid hormone therapy for benign thyroid nodules and multinodular goitres is discussed, with particular consideration of high-risk patients with prior external radiation therapy to the neck region.