Case of the Month - December

66 year old smoker presents with cough and chest discomfort.

Investigations

Left image: The chest x-ray shows right upper lobe atelectasis. The arrow shows the shrunken and opaque lobe of the lung. 

Centre image: A selected image from a CT scan of the chest demonstrates a mass (arrowed) obstructing the right upper lobe bronchus.  

Right image: The right upper lobe mass can be seen, as well as an enlarged mediastinal lymph node (arrowed). 

Bronchoscopy showed a primary malignant bronchial tumour.

 Discussion

Lung cancer has many imaging manifestations. These include central hilar mass, peripheral masses or nodules as well as lobar collapse and non resolving pneumonia.

Not all masses, collapse or non resolving pneumonias will prove to be cancer, however it is one of the most important considerations and requires exclusion.

Hilar and peripheral masses should be assessed with CT and biopsy, which can be performed percutaneously or transbronchially, dependending on location. The doubling time of lower grade cancers can be low, often in the order of 1 to 2 years. Failure to increase in size over a short interval does not exclude a cancer.

An obstructing bronchial neoplasm is an important cause of lobar collapse. In older patients all such collapses should undergo further assessment with CT and bronchoscopy to exclude a neoplasm.

Low grade lung cancers (bronchoalveolar carcinomas) can present as area of non resolving pneumonia or consolidation which may be unifocal or multifocal. The differential diagnosis for this appearance is wide, and includes various idiopathic pneumonias, atypical infections, vasculitis and autoimmune diseases. A respiratory opinion and biopsy are generally required.