Management of Heterogeneous Enlarged Thyroid Gland (Goiter) with Normal TSH
For a patient with a heterogeneous enlarged thyroid gland (goiter) without discrete nodules and normal TSH, the next step is to assess for obstructive symptoms and evaluate individual nodules using ACR TI-RADS criteria on ultrasound to determine which require fine-needle aspiration biopsy. 1, 2
Initial Clinical Assessment
Evaluate for compression symptoms that indicate need for cross-sectional imaging or surgical intervention: 1, 3
- Dyspnea or orthopnea
- Obstructive sleep apnea
- Dysphagia
- Dysphonia (voice changes)
These symptoms result from mass effect on the trachea or esophagus and help determine urgency of intervention. 1, 3
Ultrasound Characterization of Individual Nodules
Even though the ultrasound describes a "heterogeneous" gland without "discrete nodules," you must carefully review the ultrasound to identify any focal areas that can be characterized using ACR TI-RADS criteria. 2 A heterogeneous goiter often contains multiple nodules that require individual risk stratification. 4, 5
Apply ACR TI-RADS scoring to any identifiable nodular areas based on: 2, 6
- Composition (solid, cystic, mixed)
- Echogenicity (hypoechoic, isoechoic, hyperechoic)
- Shape (taller-than-wide)
- Margins (irregular, lobulated)
- Echogenic foci (microcalcifications, macrocalcifications)
Fine-needle aspiration biopsy thresholds based on TI-RADS classification: 2, 6
- TI-RADS 3 (mildly suspicious): FNA if ≥1.5 cm
- TI-RADS 4 (moderately suspicious): FNA if ≥1.0 cm
- TI-RADS 5 (highly suspicious): FNA if ≥1.0 cm
Additional Imaging for Substernal Extension
Order CT neck with contrast if: 1, 3, 2
- Patient has obstructive symptoms (dyspnea, dysphagia, orthopnea)
- Physical examination suggests substernal extension
- Ultrasound cannot visualize the inferior border of the thyroid
CT is superior to ultrasound for evaluating substernal extension and quantifying tracheal compression, which is critical for surgical planning. 1, 3, 2 The ACR specifically recommends CT over MRI due to less respiratory motion artifact. 1, 2
Management Based on Findings
If Asymptomatic with Benign Features:
Annual surveillance is appropriate with: 4, 7
- Yearly TSH measurement
- Yearly thyroid palpation
- Follow-up ultrasound at 12-24 month intervals 6
If Symptomatic with Compression:
Surgical referral is indicated when: 1, 3, 4, 7
- Significant obstructive symptoms are present
- CT demonstrates substantial tracheal compression
- Progressive growth causes increasing symptoms
Surgery is the preferred treatment for large nontoxic goiters with local compression symptoms. 7 Imaging quantifies the degree of compression and aids in operative planning. 1, 3
If FNA Shows Malignancy or Suspicious Cytology:
Refer for surgical evaluation with total thyroidectomy and appropriate lymph node dissection based on extent of disease. 1, 8
Important Pitfalls to Avoid
Do not assume "no discrete nodules" means no FNA is needed. 2, 4 Request the radiologist to characterize any focal areas using TI-RADS criteria, as heterogeneous goiters typically contain multiple nodules requiring individual assessment. 4, 5
Do not use levothyroxine suppression therapy. 7 This approach is controversial, often unsuccessful for multinodular goiters, and carries risk of iatrogenic hyperthyroidism, particularly in patients who may have subclinical autonomous function. 7
Do not order radioiodine uptake scan in euthyroid patients. 1 Scintigraphy is not helpful for determining malignancy risk when TSH is normal, as most nodules are "cold" and most cold nodules are benign. 1
Assess vocal cord mobility before any surgical intervention using ultrasound, mirror laryngoscopy, or fiberoptic laryngoscopy to document baseline function. 3