#chestxray

The differential diagnosis of a middle mediastinal mass includes lymph nodes, foregut duplication cysts, tracheal/bronchial lesions, lipoma, esophageal lesions (benign or malignant) and vascular lesions (aortic aneurysm, varices).

This case is a 70-year-old man who presented with cough and hemoptysis. Chest radiograph reveals a right mediastinal mass that silhouettes the right hilar vessels, localizing the lesion to the middle mediastinum. There is also mass effect on the trachea and widening of the right paratracheal stripe. CT reveals a mass along the right tracheal border, which also encases the right mainstem bronchus. Biopsy revealed small cell bronchial carcinoma.

Can you spot the finding that gives this case away?

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Indistinct right heart border is right middle lobe pneumonia / right middle lobe collapse until proven otherwise. This is easily confirmed on the lateral view, where the finding is usually obvious. (lateral view posted in the comments).

Take a look at today's chest radiology case.

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There is rightward shift of the mediastinum, including the trachea, indicating volume loss in the right hemithorax. The right hemidiaphragm is obscured. These are the classic findings of right lower lobe collapse.

This week we will be showing a case series of chest radiographs. Take a minute to look at the image before you read on. Can you spot the problem?

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This case demonstrates a mass at the left hilum. In addition, the left hemidiaphragm is elevated, indicating volume loss, and there is air outlining the aortic arch and proximal descending aorta (the so-called "Luftsichel sign," or "air sickle" due to its shape). Findings are classic for left upper lobe collapse (in this case post-obstructive due to the mass). The hyperinflated superior segment of the left lower lobe is what creates the air sickle, as it is situated betwixt the collapsed lung and the aorta.