What is the recommended management approach for a Bethesda 2 (Bethesda System for Reporting Thyroid Cytopathology) thyroid nodule?

Management of Bethesda 2 Thyroid Nodules

Bethesda 2 (benign) thyroid nodules require clinical observation without surgical intervention, as they have a very low malignancy risk of less than 2%. 1

Understanding Bethesda 2 Classification

Bethesda 2 nodules are characterized by:

• Benign cytology findings on fine needle aspiration (FNA)
• Low risk of malignancy (approximately 1-2%)
• Typically have benign ultrasound features (often TI-RADS 2-3)

Recommended Management Approach

Initial Management

• Reassure patient about the benign nature of the nodule 1
• Provide education on self-monitoring for significant growth or new symptoms
• No immediate intervention required for most Bethesda 2 nodules

Follow-up Protocol

• Repeat thyroid function tests in 1-3 months
• Follow-up ultrasound in 3-6 months initially
• Annual follow-up for stable, benign nodules 1
• Regular monitoring of weight and symptoms

Indications for Intervention

Consider intervention only if the nodule:

1. Causes compressive symptoms (dysphagia, dyspnea)
2. Creates cosmetic concerns
3. Shows gradual growth (especially if ≥2cm)
4. Develops suspicious features on subsequent imaging 1, 2

Intervention Options When Indicated

If intervention becomes necessary due to the above indications:

Surgical Options

• Surgical excision for nodules causing significant symptoms or with concerning growth patterns 1

Non-surgical Options

• Thermal ablation is recommended for:
  • Benign nodules that cause clinical symptoms
  • Nodules ≥2cm with gradual increase in size
  • Nodules with cosmetic concerns 2, 1

Important Considerations

Risk Assessment

Despite the benign classification, a small risk of malignancy remains (approximately 1-2%). Research has shown that benign cytology has a false-negative rate of approximately 1-3%, with one study showing a 14% malignancy rate in surgically resected Bethesda 2 nodules 3.

Ultrasound Features

Consider additional risk stratification using ultrasound characteristics:

• TI-RADS 2 features (anechoic composition, well-defined margins, no solid components) indicate <2% malignancy risk 1
• Solid structure, microcalcifications, hypoechogenicity, and increased vascularization are independent risk factors for malignancy 4

Special Situations

• For nodules with benign cytology but highly suspicious ultrasound features (TI-RADS 4c or 5), consider repeat FNA due to increased malignancy risk 5
• Pediatric patients with benign thyroid nodules may have higher resection rates than adults despite similar malignancy risks, suggesting potential overtreatment in this population 6

Pitfalls to Avoid

1. Overtreatment of benign nodules without clinical indications
2. Failure to follow up on growing nodules
3. Missing suspicious ultrasound features that might warrant closer monitoring
4. Neglecting patient symptoms that develop over time

Remember that while most Bethesda 2 nodules can be safely observed, regular follow-up is essential to monitor for any changes that might alter management recommendations.