American Board of Internal Medicine (ABIM) Certification Practice Exam

What action is recommended for a solitary pulmonary nodule greater than 4 mm and less than or equal to 6 mm with low pretest probability?

1. Follow-up CT at 2 months

2. Follow-up CT at 12 months

3. No follow-up needed

4. Immediate referral for surgical consultation

The correct answer is: Follow-up CT at 12 months

When evaluating a solitary pulmonary nodule measuring greater than 4 mm and less than or equal to 6 mm, particularly in a patient with a low pretest probability for malignancy, a follow-up CT at 12 months is considered appropriate. This approach is grounded in guidelines that emphasize a balance between careful monitoring and minimizing unnecessary interventions. In the context of low pretest probability, this indicates that the likelihood of the nodule being malignant is low based on clinical factors. Therefore, immediate invasive procedures or frequent imaging would not be justified. The recommendation for a follow-up CT at 12 months allows for sufficient time to observe any changes in the nodule's size or characteristics that might indicate a need for further evaluation, while still providing an adequate level of safety to ensure that any malignancy that might develop can be caught in a reasonable timeframe without subjecting the patient to unnecessary anxiety or interventions. Monitoring at this interval aligns with the principles of shared decision-making and the need to apply evidence-based recommendations to patient care. It also reflects a cautious yet proactive approach to a potential risk profile based on the size of the nodule and the patient's individual risk factors.