From the Guidelines
The next steps for a patient with a thyroid ultrasound showing heterogeneous echotexture with bilateral mixed nodules and a left solid nodule should include a referral to an endocrinologist for comprehensive evaluation, with consideration of fine-needle aspiration (FNA) biopsy of the left solid nodule, especially if it is larger than 1 cm or has suspicious ultrasound features, as recommended by the most recent guidelines 1.
Key Considerations
- The patient's thyroid function tests, including TSH, free T4, and possibly free T3, should be assessed to evaluate thyroid hormone status 1.
- The mixed nodules should be classified according to their size and characteristics using the Thyroid Imaging Reporting and Data System (TIRADS) to determine if they also require biopsy 1.
- The heterogeneous echotexture may indicate underlying thyroiditis, so thyroid antibody tests (anti-TPO and anti-thyroglobulin) might be ordered 1.
- Follow-up ultrasounds will likely be recommended at 6-12 month intervals to monitor for changes in nodule size or characteristics, as the majority of small thyroid cancers are indolent and proper evaluation helps distinguish between benign conditions requiring monitoring and potential cancers needing intervention 1.
Diagnostic Approach
- Fine-needle aspiration cytology (FNAC) is an important technique used along with US for the diagnosis of thyroid nodules, and should be performed in any thyroid nodule >1 cm and in those <1 cm if there is any clinical or ultrasonographic suspicion of malignancy 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 1.
- Molecular testing for thyroid nodules, including BRAF, RAS, RET/PTC, and PAX8/PPARγ mutations, may be considered to help differentiate between benign and malignant nodules 1.
From the Research
Next Steps for Thyroid Nodule Evaluation
The patient's thyroid ultrasound showing heterogeneous echotexture with bilateral mixed nodules and a left solid nodule requires further evaluation. The following steps are recommended:
- Clinical correlation: Evaluate the patient's clinical history, symptoms, and physical examination findings to determine the risk of malignancy and guide further management 2, 3.
- Functional lab tests: Order thyroid function tests (TFTs) to assess the patient's thyroid hormone levels and determine if they have hyperthyroidism or hypothyroidism 4.
- Follow-up sonogram: Schedule a follow-up thyroid ultrasound to monitor the size and characteristics of the nodules and assess for any changes or growth 5, 6.
- Fine-needle aspiration biopsy (FNAB): Consider performing FNAB on the left solid nodule and any other suspicious nodules to obtain a cytological diagnosis and guide further management 2, 3, 4.
Considerations for Heterogeneous Echogenicity
The patient's thyroid gland shows heterogeneous echogenicity, which can make it difficult to differentiate between benign and malignant nodules on ultrasound 6. Therefore:
- Caution is required during evaluation of thyroid nodules detected in thyroid parenchyma showing heterogeneous echogenicity 6.
- The diagnostic performance of ultrasound assessments may be lower in thyroid glands with heterogeneous echogenicity compared to those with homogeneous echogenicity 6.
- Microlobulated or irregular margins may be more frequently seen in benign thyroid nodules in thyroid glands with heterogeneous echogenicity 6.
Risk Stratification
The patient's thyroid nodules should be stratified according to their malignancy risk based on ultrasound features such as echogenicity, echotexture, and margins 3, 5. The following features are associated with an increased risk of malignancy: