From the Guidelines
The initial evaluation of a thyroid nodule should begin with a comprehensive history and physical examination, followed by measurement of thyroid-stimulating hormone (TSH) levels and a high-resolution thyroid ultrasound, as recommended by recent guidelines 1.
Initial Evaluation
The evaluation process should prioritize identifying risk factors that may indicate malignancy, such as prior head and neck radiation, family history of thyroid cancer, rapid nodule growth, hoarseness, dysphagia, or cervical lymphadenopathy.
- Measurement of TSH levels is crucial to determine the functional status of the nodule.
- A high-resolution thyroid ultrasound is essential for characterizing the nodule's size, composition, and suspicious features such as irregular margins, microcalcifications, hypoechogenicity, or increased vascularity.
Diagnostic Approach
Fine-needle aspiration (FNA) biopsy is the most important diagnostic step for most nodules, particularly those larger than 1-1.5 cm with suspicious ultrasound features, as it provides cytological information that guides further management 1.
- FNA should be performed in any thyroid nodule >1 cm and in those <1 cm if there is any clinical or ultrasonographic suspicion of malignancy.
- The results of FNA are very sensitive for the differential diagnosis of benign and malignant nodules, although there are limitations such as inadequate samples and follicular neoplasia.
Management
Management depends on FNA results:
- Benign nodules typically require only periodic monitoring with repeat ultrasound in 6-12 months.
- Suspicious or malignant cytology generally warrants surgical consultation.
- Indeterminate cytology may require molecular testing or diagnostic lobectomy. This systematic approach is essential because while thyroid nodules are common, only about 5-10% are malignant, making appropriate risk stratification crucial to avoid unnecessary procedures while ensuring proper treatment for potentially cancerous nodules 1.
From the Research
Initial Evaluation
The initial evaluation of a patient presenting with a thyroid nodule typically includes:
- Measurement of serum TSH to assess thyroid function 2, 3
- Ultrasonographic characteristics to guide the initial management of thyroid nodules 4, 2
- Fine needle aspiration biopsy (FNA) for cytological evaluation, especially for nodules with suspicious sonographic patterns 5, 4, 6
Management Approach
The management approach for a patient presenting with a thyroid nodule depends on the initial risk estimate, derived from ultrasound and cytology report, and includes:
- Simple observation for benign nodules 4, 2
- Local treatments, such as radioactive iodine, for selected cases 2
- Surgery for nodules with malignant cytology or compressive symptoms 4, 2
- Molecular testing for indeterminate cytology 4
Key Components of Evaluation
The key components of a thyroid nodule evaluation include:
- TSH value, which is vital to any thyroid nodule evaluation 3
- High-quality ultrasound with commentary on nodule size, structure, echogenicity, and lymph nodes 3
- Fine needle aspiration biopsy for cytological evaluation 5, 4, 6
Variation in Evaluation Quality
There is great variation in the quality of thyroid nodule evaluations before surgical referral, with many evaluations lacking a TSH value or a high-quality ultrasound 3