Wednesday, 3 June 2015

xrayoftheweek 22: abnormality and differential diagnosis?

It's a slightly tricky chest x-ray for this week's #xrayoftheweek. Can you see any abnormalities on this x-ray, and what is your differential diagnosis?
(hint: the background lung parenchyma looks a little "noisy" but is otherwise normal)


At least two well defined and rounded soft tissue density nodules are seen on the right side, one at the apex and one medially at the base. None are seen on the left side, and there is no other abnormality. There is a "normal" azygous fissure.

The differential list for multiple nodules of this size has metastases at the top. It's an odd appearance for other nodules such as rheumatoid nodules, and doesn't really look like an infective process. Hamartomas and granulomas are also possible. They could be extrinsic to the lungs too, such as skin based lesions. 

The one not to forget is pulmonary arterio-venous malformations (pAVMs) - direct shunts between the pulmonary arterial and pulmonary venous systems, and therefore right-to-left shunts. These may present either incidentally, or in someone with symptoms from them such as difficulty breathing or embolic phenomena. The most common associations of pAVMs are with hereditary haemorrhagic telangiectasia (HHT), liver cirrhosis and mitral stenosis. Treatment options include embolization and surgery.

This is a thick-MIP coronal CT image from the same person showing a lobulated lesion in the right lower zone with feeding and draining vessels.


#FOAMrad #FOAMed #meded