What is the recommended management approach for a benign follicular nodule with cystic degeneration classified as Bethesda category 2?

Management of Benign Follicular Nodules with Cystic Degeneration (Bethesda Category 2)

For benign follicular nodules with cystic degeneration classified as Bethesda category 2, observation is the recommended management approach as these nodules have a malignancy risk of less than 1%. 1

Risk Assessment

• Benign follicular nodules with cystic degeneration classified as Bethesda category 2 have a risk of malignancy <1% when they show typical benign sonographic features 1
• The incidence of malignancy in Bethesda category 2 nodules is approximately 1.53% based on surgical specimens 2
• Degenerating nodules are primarily benign thyroid nodules and may show ultrasound features that mimic malignancy due to intranodular hemorrhage and impaired blood supply 3

Management Algorithm Based on Nodule Size

For Nodules <2 cm:

• Observation is appropriate for asymptomatic nodules with maximal diameter <2 cm 1
• No routine follow-up is necessary if the nodule is stable and asymptomatic 1
• Consider repeat ultrasound in 1 year to confirm stability 1

For Nodules 2-10 cm:

• Follow-up ultrasound in 8-12 weeks for postmenopausal women 1
• Follow-up ultrasound in 1 year for premenopausal women 1
• Consider repeat fine-needle aspiration (FNA) if there are changes in size or sonographic features 1

For Nodules >10 cm:

• Consider referral to a specialist for further evaluation 1
• Larger nodules may require more aggressive management due to potential for compressive symptoms 4

Follow-up Protocol

• Ultrasound evaluation at regular intervals (6-12 months initially, then annually if stable) 1
• Physical examination with or without ultrasound every 6 to 12 months for 1 to 2 years to assess stability 4
• If the lesion increases in size, repeat tissue sampling should be considered 4
• If the lesion remains stable, return to routine screening 4

Intervention for Symptomatic Nodules

• Thermal ablation is indicated for benign nodules that cause clinical symptoms, create cosmetic concerns, or have maximal diameter ≥2 cm 1
• Therapeutic aspiration can be performed for simple cysts with persistent clinical symptoms 4
• For complicated cysts that increase in size on follow-up, a tissue biopsy should be performed 4
• Surgical management should be considered for nodules with compressive symptoms not responsive to less invasive approaches 1

Special Considerations

• For cystic nodules classified as complicated (BI-RADS category 3), options include aspiration or short-term follow-up with physical examination and ultrasound 4
• If blood-free fluid is obtained on aspiration and the mass resolves, the patient should be monitored for any change 4
• If the mass recurs after aspiration, ultrasound with image-guided biopsy or surgical excision is warranted 4

Common Pitfalls to Avoid

• Overtreatment of asymptomatic, stable benign nodules - most require only observation 1
• Misinterpreting degenerating nodules as malignant based solely on ultrasound features that may mimic cancer 3
• Unnecessary surgery for benign nodules that could be managed conservatively 1
• Failure to recognize that even benign nodules require follow-up to ensure stability, as a small percentage (1.53%) may harbor malignancy 2