American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the follow-up protocol for a solitary pulmonary nodule greater than 6 mm and less than or equal to 8 mm with high pretest probability?

1. Initial follow-up CT at 1 to 3 months

2. Initial follow-up CT at 3 to 6 months

3. No follow-up needed

4. Immediate imaging with MRI

The correct answer is: Initial follow-up CT at 3 to 6 months

In the context of a solitary pulmonary nodule (SPN) that measures greater than 6 mm and less than or equal to 8 mm with a high pretest probability of malignancy, the recommended follow-up protocol is to perform an initial follow-up CT scan at 3 to 6 months. This approach is aligned with the guidelines for evaluating pulmonary nodules and reflects a careful balance of monitoring potential malignancy while minimizing unnecessary procedures. The rationale for this follow-up timing includes the need to assess changes in the nodule's characteristics that could indicate growth, which is a key factor in determining the likelihood of cancer. In nodules of this size, performing a CT scan too early (like at 1 to 3 months) could lead to unnecessary anxiety and possibly false-positive findings, as benign nodules may not show changes in such a short time frame. The time frame of 3 to 6 months is established based on data showing that significant changes in nodules with higher risk factors are more likely to be detected during this period. The options involving no follow-up or immediate imaging with MRI are not appropriate in this scenario. No follow-up could lead to missing an early diagnosis of lung cancer, and MRI is typically not the preferred imaging modality