From the Guidelines
A 1.1 cm thyroid nodule typically requires further evaluation with fine needle aspiration (FNA) biopsy to rule out malignancy, as thyroid nodules larger than 1 cm generally warrant investigation, as recommended by the most recent guidelines 1.
Key Considerations
- The nodule's size is a critical factor in determining the need for investigation, with nodules larger than 1 cm generally requiring further evaluation.
- Before proceeding with FNA, a complete thyroid ultrasound should be performed to assess nodule characteristics, including echogenicity, margins, shape, calcifications, and vascularity, which help determine cancer risk, as suggested by 2 and 1.
- Thyroid function tests (TSH, free T4) should also be obtained to check for hyper- or hypothyroidism, as recommended by 3 and 4.
Management
- If the nodule has suspicious ultrasound features, FNA should be performed regardless of size, as recommended by 2 and 1.
- After FNA, management depends on cytology results: benign nodules typically require monitoring with repeat ultrasound in 6-12 months, while suspicious or malignant results may necessitate surgical consultation, as suggested by 2, 1, 3, and 4.
Risk of Malignancy
- The concern with thyroid nodules is the approximately 5-15% risk of malignancy, though most are benign, as reported by 2 and 1.
- Patients should be monitored for symptoms like difficulty swallowing, voice changes, or neck discomfort, which might indicate nodule growth requiring intervention regardless of cytology results, as recommended by 2 and 1.
From the Research
Significance of a 1.1cm Thyroid Nodule
The significance of a 1.1cm thyroid nodule can be understood by considering the following points:
- Thyroid nodules are very common lesions, and despite the majority being benign, a significant percentage may have underlying malignancy 5.
- Fine-needle aspiration (FNA) biopsy is a safe, useful, and cost-effective procedure for the diagnostic investigation of thyroid nodules, and its results can be helpful in determining the indication for surgery 5, 6.
- The distinction between benign and malignant lesions cannot be precisely made with thyroid function tests, scintigraphy, or ultrasonography alone, and FNA biopsy is considered the most reliable diagnostic method for this purpose 7, 6.
- The size of the nodule is an important factor in determining the risk of malignancy, but the provided studies do not specifically address the risk associated with a 1.1cm nodule.
- However, it is known that larger nodules (greater than 4 cm) have a higher risk of malignancy, and FNA biopsy can be used to distinguish malignancy in these cases, although histopathology remains the preferred method for confirmation 8.
- For smaller nodules, such as a 1.1cm nodule, the approach may involve careful clinical follow-up, and FNA biopsy may be considered if there are suspicious features or if the nodule is growing over time 5, 6.
Diagnostic Evaluation
The diagnostic evaluation of a thyroid nodule may involve:
- Thyroid function tests
- Scintigraphy
- Ultrasonography (USG)
- Fine-needle aspiration biopsy (FNAB)
- Histopathology (after surgery)
- The choice of diagnostic test depends on the clinical presentation, nodule size, and other factors, and FNA biopsy is often used to guide the decision for surgery 5, 7, 6, 9.
- The results of FNA biopsy can be classified using the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), which helps to standardize the reporting and management of thyroid nodules 7.
Management
The management of a thyroid nodule depends on the results of the diagnostic evaluation and may involve: