Incidental lung nodules are increasingly detected. Here is how we risk-stratify them and when a surgical approach is indicated.
With CT scanning now performed routinely for many chest and abdominal complaints, the incidental discovery of a lung nodule has become increasingly common. A "nodule" is simply a small rounded opacity — in practical terms, a spot — seen on the scan, typically smaller than 3 centimetres.
The critical question, of course, is: what does it mean?
Most Nodules Are Not Cancer
The majority of incidentally found lung nodules are benign — caused by old granulomatous infections (such as tuberculosis, very prevalent in South Africa), small lymph nodes, or minor scarring. However, a proportion will represent early lung cancer or metastatic disease from another site, so they cannot be dismissed without proper assessment.
How We Risk-Stratify
A structured approach is used, incorporating:
Size: Nodules under 6mm carry very low risk and require only periodic surveillance. Those above 8mm warrant more active investigation.
Morphology: Solid, part-solid, or pure "ground-glass" nodules each carry different implications. Irregular or spiculated (spiky) edges raise suspicion.
Growth over time: A nodule that doubles in volume in less than 400 days is concerning. Stability over two years is reassuring.
Patient risk factors: Smoking history, age, family history of lung cancer, and prior malignancy all influence the pretest probability.
We typically follow established guidelines (Fleischner Society or BTS) to decide the appropriate surveillance interval or escalation pathway.
When Surgery Is Indicated
If a nodule grows, has high-risk features, or cannot be safely characterised by biopsy, surgical resection is appropriate. This serves two purposes simultaneously: definitive diagnosis and potential cure, if the lesion proves malignant at an early stage.
Most resections for nodules are performed using video-assisted thoracoscopic surgery (VATS) — keyhole surgery through small chest-wall incisions. Recovery is generally quicker than open thoracotomy, with most patients discharged within two to three days.
The most important message: if you have been told about a lung nodule, ensure it is being actively followed up. Do not assume that the absence of symptoms means the nodule can be ignored.