What causes abnormal CT in non-smokers?

Question

Hello doctor,

I am very scared right now and need some clarity. Can a mucus plug in a 35-year-old look like lung cancer on an abnormal CT scan result?

My brother had a persistent cough and mild breathlessness for about six weeks, so his GP ordered a chest CT scan. The radiologist’s report came back mentioning a focal opacity in the right middle lobe with irregular borders that cannot exclude malignancy, and now we are all panicking badly.

His pulmonologist mentioned it could be a mucus plug or post-obstructive pneumonia rather than actual lung cancer, but said they need more investigation to be sure.

My brother is a non-smoker with no family history of lung cancer, and his only medical history is mild asthma for which he uses a salbutamol inhaler. His blood work shows slightly elevated eosinophils at 0.7, which the doctor said might be relevant.

They have scheduled a bronchoscopy next week and a repeat HRCT in six weeks, but we cannot wait that long without knowing more. How common is it for benign conditions like a mucus plug to genuinely mimic lung cancer on a CT scan? What other conditions could cause this kind of abnormal CT scan result in a young non-smoking asthmatic?

Please help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

I understand why this report would cause anxiety. When a CT (computerized tomography) scan report mentions that malignancy cannot be excluded, it is often written as a precaution because imaging alone cannot always provide a definite diagnosis. In many cases, especially in younger non-smokers, findings that initially look suspicious later turn out to be benign conditions.

Yes, a mucus plug can sometimes mimic a mass or focal opacity on a CT scan. When thick mucus blocks a bronchus, the lung segment beyond it may partially collapse or become inflamed.

This can produce an irregular opacity on imaging that may look concerning until further evaluation is done. Bronchoscopy is often helpful in these situations because it allows the doctor to directly examine the airway and remove any mucus obstruction if present.

Your brother’s history of asthma and the mildly elevated eosinophil count are also relevant. In asthmatic individuals, mucus plugging and airway inflammation can occasionally produce localized changes in the lung that appear abnormal on CT scans. In addition to mucus plugs, conditions such as focal infection, inflammatory nodules, or post-obstructive pneumonia can create similar appearances.

The plan for bronchoscopy, along with repeat imaging,g is a standard and appropriate approach. Many times, if the cause is mucus or inflammation, the abnormality improves or disappears on follow-up imaging once the airway clears or the inflammation settles.

I hope this helps.

Kindly follow up if you have more concerns.

Thank you.