Chest x rays made easy
In the final part of the series, Elizabeth Dick looks at lung nodules and masses.
Discrete nodules do not have a reticular or linear component. They can be small (up to 5 mm) or large. The differential diagnosis is shown in box 1 and some of them are illustrated in figures 1, 2, and 3.
Abnormality: single nodule or mass in the lung The two main causes of a single mass in the lung are: infection/ - for example, tuberculosis and neoplasm - for example, primary bronchial tumour or single metastasis. In both cavitation may occur.
Other causes of single or multiple masses in the lung are rare. Only mention them if pressed by an examiner. They include hydatid cyst and pulmonary arteriovenous malformation.