What management is recommended for a patient with Thyroid Imaging Reporting and Data System (TI-RADS) 3 findings on thyroid ultrasound?

Management of TI-RADS 3 Thyroid Nodules

For patients with TI-RADS 3 findings on thyroid ultrasound, observation without fine needle aspiration (FNA) is recommended for nodules smaller than 1.5 cm, with follow-up ultrasound surveillance being the appropriate management strategy. 1, 2

Understanding TI-RADS 3 Classification

• TI-RADS 3 nodules are categorized as "mildly suspicious" with a low risk of malignancy (approximately 1.2-1.8%) 3
• These nodules have some concerning features but not enough to warrant immediate biopsy unless they meet size criteria 1, 2
• The primary goal of TI-RADS is to standardize thyroid ultrasound reporting and minimize unnecessary FNA procedures 1

Management Algorithm Based on Nodule Size

For TI-RADS 3 nodules <1.5 cm:

• Observation without FNA is recommended 1, 2
• Follow-up ultrasound surveillance is appropriate 2, 3
• The clinical significance of detecting small thyroid cancers is generally considered low 1

For TI-RADS 3 nodules ≥1.5 cm but <2.5 cm:

• FNA should be considered 2
• Assessment of thyroid function tests should be included in initial evaluation 2

For TI-RADS 3 nodules ≥2.5 cm:

• FNA is recommended 2, 3
• Observation is appropriate only if the patient is asymptomatic 2

Follow-up Protocol

• Regular ultrasound surveillance is recommended for TI-RADS 3 nodules that do not meet criteria for FNA 2, 3
• Follow-up intervals typically range from 1-3 years, depending on nodule stability 2
• Any significant change in size or characteristics during follow-up should prompt reassessment 2

Important Considerations and Caveats

• The risk of missing malignancy with this approach is very low (1.2-1.8%) 3
• Studies show that ACR TI-RADS scoring is 98.8% specific for identifying benign nodules 3
• Adjusting size thresholds to catch more potential malignancies would significantly increase unnecessary procedures for predominantly benign nodules 4
• Clinical risk factors may warrant more aggressive evaluation regardless of TI-RADS score, including:
  • History of head and neck irradiation 1
  • Family history of thyroid cancer 1, 5
  • Suspicious physical exam findings (firm, fixed nodule, rapid growth) 1
  • Presence of suspicious cervical lymphadenopathy 1, 6

Rationale for Conservative Management

• Most malignant nodules that would not be biopsied under ACR TI-RADS guidelines would either undergo ultrasound follow-up or be smaller than 1 cm 4
• Smaller papillary thyroid cancers have a lower potential for relapse after treatment 1
• The overall rate of thyroid cancer in patients with nodules is less than 3-5%, with generally favorable prognosis 1
• Population screening with neck ultrasound is not recommended by WHO due to the favorable prognosis of most thyroid cancers 1

This approach balances the need to identify clinically significant thyroid cancers while avoiding unnecessary procedures for the vast majority of benign nodules.