Are Lung Nodules Equal to Lung Cancer?

Are Lung Nodules Equal to Lung Cancer?

What exactly is the relationship between lung nodules and lung cancer?

1. What are Lung Nodules?

Lung nodules appear as focal, round, solid or sub-solid pulmonary opacities with a diameter of ≤30mm on lung imaging. They can be solitary or multiple and are not accompanied by lung collapse, hilar lymph node enlargement, or pleural effusion.

Based on the size of lung nodules:

• Nodules <5mm in diameter are called micro-nodules.
• Nodules 5mm-10mm in diameter are called small lung nodules.
• Nodules 11mm-30mm in diameter are called lung nodules.

According to chest CT, lung nodules can be classified into pure ground-glass nodules (PGGN), solid nodules, and partially solid nodules (PSN).

2. Are Lung Nodules Equal to Lung Cancer?

No! The malignancy rate of lung nodules found during physical examinations is actually less than 5%.

• For nodules smaller than 5mm: The possibility of malignancy is less than 1%.
• For lung nodules 5-8mm: The malignancy rate is between 2-6%.
• For lung nodules 8-20mm: The malignancy rate is about 18%.
• For lung nodules larger than 20mm (more than 2cm): The malignancy rate increases significantly and can be higher than 50%.

3. How to Follow Up on Lung Nodules?

• For <5mm lung nodules, consider whether the patient has high-risk factors (elderly men, smoking, family history of cancer, etc.). If no high-risk factors exist, follow-up is not required. If high-risk factors are present, an annual chest CT is recommended.
• For 5-10mm lung nodules, the doctor will comprehensively judge the risk based on the specific condition of the nodule and whether the patient has high-risk factors, ultimately determining the follow-up interval. Therefore, close follow-up under professional medical guidance is necessary.
• For lung nodules ≥10mm, early diagnosis and treatment are recommended.