What is the approach to diagnosing, evaluating, and managing thyroid nodules?

From the Guidelines

Thyroid nodules should be evaluated with a thorough history, physical examination, thyroid function tests, and ultrasound imaging, and fine-needle aspiration biopsy (FNAB) is recommended for nodules larger than 1 cm or those with suspicious features on ultrasound, as stated in the 2012 ESMO guidelines 1. When evaluating thyroid nodules, it is essential to consider the patient's history, physical examination, thyroid function tests, and ultrasound imaging to determine the risk of malignancy.

• The 2012 ESMO guidelines recommend using ultrasound as a first-line diagnostic procedure for detecting and characterizing nodular thyroid disease 1.
• US features associated with malignancy include hypoechogenicity, microcalcifications, absence of peripheral halo, irregular borders, solid aspect, intranodular blood flow, and shape (taller than wide) 1.
• FNAC should be performed in any thyroid nodule >1 cm and in those <1 cm if there is any clinical or ultrasonographic suspicion of malignancy, as recommended by the 2012 ESMO guidelines 1.
• The results of FNAC are very sensitive for the differential diagnosis of benign and malignant nodules, although there are limitations, such as inadequate samples and follicular neoplasia, as noted in the 2010 ESMO guidelines 1.
• In the event of inadequate samples, FNAC should be repeated, while in the case of follicular neoplasia, with normal thyroid-stimulating hormone (TSH) and ‘cold’ appearance at thyroid scan, surgery should be considered, as stated in the 2010 ESMO guidelines 1.
• Treatment depends on the biopsy results, and malignant nodules generally require surgical removal, typically thyroidectomy, as recommended by the 2010 ESMO guidelines for the initial treatment of differentiated thyroid carcinoma (DTC) 1.
• Benign nodules typically require only monitoring with repeat ultrasound in 6-12 months, and for indeterminate nodules, molecular testing may help determine malignancy risk, as noted in the 2012 ESMO guidelines 1.
• Functional (hot) nodules causing hyperthyroidism can be treated with radioactive iodine, antithyroid medications like methimazole, or surgery, and most thyroid nodules are benign and asymptomatic, requiring no intervention beyond monitoring, as stated in the example answer.
• The evaluation process is crucial because approximately 5-15% of thyroid nodules are malignant, and early detection of thyroid cancer generally leads to better outcomes with high cure rates, as noted in the example answer.

From the Research

Diagnosis of Thyroid Nodules

• Thyroid nodules are common in clinical practice and may be solitary or dominant within a multinodular goiter 2
• The differential diagnosis of a thyroid nodule is crucial, as malignancy necessitates surgery, while strict patient follow-up is necessary in the case of benignity 2
• Fine-Needle Aspiration biopsy is considered to be the "gold standard" in the selection of patients for surgery 2
• Ultrasonography (US) can be used to determine changes in the size of nodules during follow-up or to detect recurrent lesions in patients suspected for thyroid malignancy 2

Workup of Thyroid Nodules

• There are four key components to thyroid nodule assessment: clinical history and examination, serum thyroid stimulating hormone (TSH) measurement, ultrasound, and, if indicated, fine-needle aspiration (FNA) 3
• Thyroid ultrasonography should be performed only for palpable goitre and thyroid nodules and by specialists with expertise in thyroid sonography 3
• FNA may be performed for nodules ≥ 1.0 cm depending on clinical and sonographic risk factors for thyroid cancer 3
• FNA specimens should be read by an experienced cytopathologist and be reported according to the Bethesda Classification System 3

Treatment of Thyroid Nodules

• Surgery is mandatory in cytologically malignant nodules or in cases suspicious for malignancy 2
• Surgery is indicated for FNA findings of malignancy or indeterminate cytology when there is a high risk clinical context 3
• Surgery may also be indicated for suspicion of malignancy; larger nodules, especially with symptoms of mass effect; and in some patients with thyrotoxicosis 3
• Active surveillance or local ablative treatments might be beneficial for appropriately selected patients 4
• A personalized, risk-based protocol promotes high-quality care while minimizing costs and unnecessary testing 4