The chest radiograph one month later was reported as unchanged and no further suggestions were made by the radiologist. The clinician took no further action.
The patient came back ten months later, and a new radiograph showed an obvious increase in size of the nodule (B, arrow) when compared to the initial film (A, arrow)
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Enhanced CT confirms the increase in size of the nodule (A-B, arrows). Surgery discovered a carcinoma in the wall of a bulla.
Final diagnosis: adenocarcinoma of the lung associated to bullous disease.
Lung carcinoma seems to occur more often in bullous disease, although there is not enough evidence compiled at the present time. Despite the lack of evidence, knowing
this association may prevent misdiagnosis.
A lesser known fact is that the cystic space may disappear after the carcinoma develops, as occurred in a second case (see below). Spontaneous regression of a bulla may be due to non-malignant causes, but carcinoma should be excluded with CT because it may take years for the lesion to be visible in the chest radiograph.
I am showing this case because the opinion given in the chest radiograph was unequivocal, whereas the CT report was vapid, giving the impression that the nodule was infectious, and that malignancy was less likely. The follow-up radiograph was disregarded by the radiologist and clinician and this caused a delay in diagnosis of almost one year.
To complete the information, I am showing a second case of carcinoma developing in the wall of a cystic space
Images of the second case were obtained during routine CT screening in a 72-year-old man, heavy smoker.
Apical axial CT image shows a small nodule in the LUL (A, arrow), with increased uptake on PET-CT (C, arrow). There is a cystic airspace in the LLL (B, arrow) with no PET-CT uptake, interpreted as a non-specific cystic airspace lesion.
At surgery a carcinoma of the LUL was found.
It was decided to continue with yearly follow-up studies. The cystic air space (A, arrow) increased in size in 2008 but still had a thin wall (B, arrow). In 2009 it has decreased slightly in size and the wall is thicker than the previous year (C, arrow). A new PET-CT shows increased uptake in the posterior wall (D, arrow).
Malignancy was suspected. The patient refused further surgery or percutaneous biopsy and it was decided to do a follow up study three months later.
Axial CT shows that the cystic airspace has disappeared and in its place, a solid mass has developed (A and B, arrows) with increased overall uptake on PET-CT (C, arrow). At surgery, an adenocarcinoma was found.
Final diagnosis: adenocarcinoma arising in the wall of a cystic airspace, which disappeared as the tumour progressed.
Follow Dr. Pepe’s advice:
1. Bullous emphysema and isolated cystic spaces may be associated with an increased incidence of carcinomas
2. A poorly worded report may cause an unnecessary delay in diagnosis