What is the diagnosis for a patient with an enlarged left thyroid lobe, bilateral thyroid nodules with a TI-RADS (Thyroid Imaging Reporting and Data System) 3 classification and an F2 score on elastography, and a lesion in the left submandibular region suspected to be an ectopic thyroid nodule?

From the Guidelines

The patient's thyroid nodules with a TI-RADS 3 classification and an F2 score on elastography suggest intermediate risk nodules that require follow-up but are likely benign, and I recommend a follow-up ultrasound in 6-12 months to monitor the thyroid nodules for any changes in size or characteristics. The presence of bilateral thyroid nodules and an enlarged left thyroid lobe with retrosternal extension, as well as a lesion in the left submandibular region suspected to be an ectopic thyroid nodule, should be evaluated further. According to the American College of Radiology Appropriateness Criteria for thyroid disease 1, ultrasound is the best imaging study to evaluate thyroid morphology and can be a helpful adjunct study to a radioiodine uptake scan.

For the submandibular lesion, a thyroid uptake scan (nuclear medicine imaging) would be appropriate to determine if it represents functioning thyroid tissue, as suggested by the ESMO clinical recommendations for diagnosis, treatment, and follow-up of differentiated thyroid cancer 1. Blood tests including TSH, free T4, and thyroid antibodies should be performed to assess thyroid function. Fine needle aspiration (FNA) biopsy may be considered for any nodules larger than 1.5 cm or those with suspicious features, as recommended by the ESMO clinical guidelines 1.

The TIRADS 3 classification suggests a low to intermediate risk of malignancy (approximately 5-10%), and the F2 elastography score indicates moderate stiffness, which is generally reassuring 1. The retrosternal extension should be monitored but typically doesn't require intervention unless causing compressive symptoms like difficulty swallowing, breathing issues, or voice changes. If symptoms develop, surgical consultation would be warranted.

Key points to consider in the diagnosis and management of this patient include:

• Monitoring the thyroid nodules with follow-up ultrasound in 6-12 months
• Evaluating the submandibular lesion with a thyroid uptake scan
• Assessing thyroid function with blood tests
• Considering FNA biopsy for nodules larger than 1.5 cm or those with suspicious features
• Monitoring the retrosternal extension for compressive symptoms.

From the Research

Diagnosis of Thyroid Nodules

The diagnosis of thyroid nodules involves various imaging modalities and diagnostic procedures. For a patient with an enlarged left thyroid lobe, bilateral thyroid nodules with a TI-RADS 3 classification, and an F2 score on elastography, the following points are relevant:

• The TI-RADS 3 classification indicates a moderate suspicion of malignancy, with a reported malignancy rate of 2.87% in one study 2.
• The F2 score on elastography suggests a higher stiffness of the nodule, which is associated with a higher risk of malignancy 3, 4, 5, 6.
• The presence of an ectopic thyroid nodule in the left submandibular region is a rare occurrence and may require further evaluation to determine its nature and potential impact on the diagnosis and treatment plan.

Diagnostic Procedures

The diagnostic procedures for thyroid nodules include:

• Fine-needle aspiration biopsy (FNAB), which is an important tool for diagnosing thyroid nodules, but may have limitations in terms of nondiagnostic results 3.
• Ultrasound elastography, which can help to enhance the cellularity of biopsy specimens and reduce nondiagnostic results by targeting the harder areas of the nodule 3.
• Shear wave elastography, which can assess the malignant potential of thyroid nodules based on their stiffness, with higher shear wave velocities indicating a higher risk of malignancy 5, 6.
• American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TIRADS) scoring system, which can help to stratify the risk of malignancy based on ultrasound features and nodule size 2, 6.

Risk Stratification

The risk stratification of thyroid nodules is crucial for determining the appropriate diagnostic and treatment approach. The following points are relevant:

• The TIRADS classification system can help to identify nodules with a higher risk of malignancy, with TIRADS 3 nodules having a moderate suspicion of malignancy 2.
• The elastography scores, such as the F2 score, can provide additional information on the stiffness of the nodule and its potential risk of malignancy 3, 4, 5, 6.
• The combination of ultrasound features, elastography scores, and TIRADS classification can help to improve the diagnostic accuracy and risk stratification of thyroid nodules 5, 6.