Imaging Case of the Week 85

The following chest x-ray images are from a man in his 30s who has presented with chest pain and dyspnoea that has persisted for the past few weeks.

What imaging sign can you see and what could be the diagnosis?

chest x-ray PA view

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chest x-ray lateral view

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[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]

The chest x-rays show ‘hilum overlay’ sign.

There is a large hilar mass on the right side through which the hilar structures can be visualised. This indicates that the mass is superimposed on the hilum.

The lateral view shows obliteration of the retrosternal clear space which means that the mass is arising from the anterior mediastinum.

cxr hilum overlay sign

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lateral cxr anterior mediastinal mass

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Causes of anterior mediastinal masses can be the 4 Ts:

  • Thymoma
  • Teratoma
  • Thyroid (retrosternal)
  • Terrible lymphoma

CT guided biopsy identified the mass to be T cell lymphoma.

(Reference: Fundamentals of Diagnostic Radiology, Brant & Helms)