What is the next step in managing a patient with a multinodular thyroid gland and bilateral solid nodules, including one with worrisome appearance and a calcified focus?

Management of Multinodular Thyroid Gland with Suspicious Nodules

Fine-needle aspiration biopsy (FNAB) should be performed on the worrisome nodule in the left lobe with internal vascularity (0.88 x 0.53 cm) and the calcified focus (0.62 x 0.54 cm), as these features suggest potential malignancy despite being less than 1 cm in size. 1

Rationale for FNAB

While most thyroid nodules are benign (approximately 95%), the presence of specific suspicious ultrasonographic features warrants further investigation even for nodules smaller than 1 cm 2, 1:

• The nodule with internal vascularity in the left lobe (0.88 x 0.53 cm) shows concerning features
• The calcified focus (0.62 x 0.54 cm) is particularly worrisome as microcalcifications are associated with papillary thyroid carcinoma
• The multinodular appearance with heterogeneous texture and increased vascularity throughout the gland adds to the overall risk profile

Diagnostic Algorithm

1. FNAB of suspicious nodules: Target the left lobe nodule with internal vascularity and the calcified focus 1

   • These nodules meet criteria for biopsy despite being <1 cm due to suspicious sonographic features
   • FNAB should be performed under ultrasound guidance for accuracy

2. Laboratory assessment:

   • Thyroid function tests (TSH, free T4) to determine functional status
   • Consider serum calcitonin measurement to rule out medullary thyroid cancer 2

3. Risk stratification based on FNAB results:

   • Benign: Follow-up with ultrasound in 6-12 months
   • Nondiagnostic: Repeat FNAB
   • Indeterminate/suspicious/malignant: Proceed to surgical consultation

Surgical Considerations

If FNAB results indicate malignancy or are highly suspicious:

• For nodules ≥1 cm: Total or near-total thyroidectomy is the standard approach 2, 1
• For nodules <1 cm with malignant cytology: The extent of surgery depends on risk factors
  • Unifocal, intrathyroidal tumors with favorable histology may be treated with lobectomy
  • Multifocal disease (as suggested by the multinodular appearance) may require total thyroidectomy 1

Follow-up Recommendations

If FNAB results are benign:

• Regular ultrasound surveillance every 6-12 months initially, then annually if stable
• Monitor for changes in size, appearance, or new suspicious features
• Repeat FNAB if significant growth or development of new suspicious features occurs

Important Considerations

• Surgical complications such as laryngeal nerve palsy and hypoparathyroidism are rare (<1-2%) when performed by experienced surgeons 1
• The presence of multiple nodules increases the risk of missing a malignant lesion, making targeted FNAB of the most suspicious nodules crucial
• Despite the small size of the suspicious nodules (<1 cm), their concerning ultrasound features override the general recommendation to observe nodules <1 cm 1, 3

The management approach prioritizes identifying potential malignancy while avoiding unnecessary procedures for benign disease, as this directly impacts patient morbidity, mortality, and quality of life.