American Board of Internal Medicine (ABIM) Certification Practice Exam

According to the Fleischner criteria, what is the follow-up recommendation for a subcentimeter solitary solid pulmonary nodule that is ≤4 mm with low pretest probability?

1. Follow-up CT at 6 months

2. Follow-up is not needed

3. Immediate biopsy

4. Follow-up with a PET scan

The correct answer is: Follow-up is not needed

The appropriate follow-up recommendation for a subcentimeter solitary solid pulmonary nodule that is 4 mm or smaller with a low pretest probability, according to the Fleischner criteria, is that follow-up is not needed. This guideline is based on the recognition that small nodules, particularly those that are less than or equal to 4 mm in size, have a very low likelihood of being malignant when the pretest probability of lung cancer is low. Consequently, routine imaging follow-up is unnecessary, avoiding unnecessary radiation exposure and anxiety for the patient. The Fleischner criteria emphasize the importance of nodule size and patient risk factors when determining the need for follow-up. For larger nodules or those with intermediate or high pretest probability, more rigorous follow-up protocols, such as imaging at specific intervals or even biopsy in certain cases, would be recommended. However, in this specific scenario of a very small nodule with low suspicion for cancer, the guideline indicates that active surveillance is not indicated.