Pulmonary Nodules
Fleischner Society · 2017 · Updated 2017 (reaffirmed 2023)
Evidence-based management of incidental pulmonary nodules on CT: solid, subsolid, ground-glass, and multiple. Size and risk stratify every follow-up interval.
Solid <6 mm low-risk: no routine follow-up. Subsolid >6 mm: CT at 6–12 mo then 2-yearly to 5 y.
Incidentally detected pulmonary nodules on CT · Adults ≥ 35 years old · Solid, part-solid, ground-glass and multiple nodules
Patients enrolled in lung cancer screening (use Lung-RADS) · Patients with known primary malignancy · Immunocompromised patients · Age < 35 years
CT
Consensus statement — expert-panel driven
Risk-stratify by size, density and patient risk. Solid <6 mm low-risk needs no follow-up. Subsolid nodules are followed longer because adenocarcinoma-spectrum lesions grow slowly.
Overview
The Fleischner Society 2017 guideline replaced the 2005/2013 recommendations and unifies management of solid, subsolid and multiple pulmonary nodules discovered incidentally on CT in adults. Recommendations are stratified by nodule density, size and estimated malignancy risk, with explicit thresholds for no follow-up, surveillance CT, PET/CT and tissue sampling.
Quick reference
| Size / risk | Recommendation |
|---|---|
| <6 mm, low risk | No routine follow-up |
| <6 mm, high risk | Optional CT at 12 months |
| 6–8 mm, low risk | CT 6–12 mo, then 18–24 mo |
| 6–8 mm, high risk | CT 6–12 mo, then 18–24 mo |
| >8 mm | CT at 3 mo, PET/CT or tissue sampling |
| Type / size | Recommendation |
|---|---|
| Ground-glass <6 mm | No routine follow-up |
| Ground-glass ≥6 mm | CT at 6–12 mo, then every 2 y to 5 y |
| Part-solid <6 mm | No routine follow-up |
| Part-solid ≥6 mm | CT at 3–6 mo; if persistent, annual CT to 5 y |
Decision algorithm
Follow-up recommendations for the incidental pulmonary nodule on CT, stratified by density, size, and clinical risk.
References
- MacMahon H et al. Radiology 2017
MacMahon H, Naidich DP, Goo JM, et al. Guidelines for management of incidental pulmonary nodules detected on CT images: From the Fleischner Society 2017. Radiology 2017;284(1):228-243.