Cáceres’ Corner Case 216 – SOLVED!

Dear Friends,

Today I am showing another case provided by my friend Dr. López Moreno. Radiographs belong to a 25-year-old woman with fainting spells. 

What do you see?

More images will be shown on Wednesday.

Dear Friends,

Showing coronal and sagittal images of enhanced CT.
What do you see?

Click here to see more images

Click here to see the answer

Findings: PA radiograph shows convexity of the aorto-pulmonary window (A, arrow) which is encroaching upon the left hilum. Aside from a discrete pectus excavatum, I don’t see any significant findings in the lateral view (B).

According to Diploma 144, the main causes of a prominent A-P window are either enlarged lymph nodes or an arterial aneurysm and a CT should be obtained. In this particular patient coronal enhanced CT shows an aortic aneurysm projecting over the A-P window (C, arrow) and located anterior to the aortic arch in the sagittal projection (D, arrow).

The appearance is compatible with traumatic pseudoaneurysm, but the patient did not have any antecedent of traumatism. In our opinion (Dr López Moreno and mine) we believe that it represents a ductus aneurysm because of the location and the thin band joining the aneurysm and the pulmonary artery (E, circle). The pinpoint calcification in the middle of the band may be calcium in the ductus ligament or be secondary to partial-volume effect.

An unexpected finding is the compression of the left main bronchus by the aneurysm (E-F, arrows). It would have been interesting to perform expiration films to detect air-trapping of the left lung.

Some of you have mentioned Kommerel diverticulum. This malformation is located posteriorly and occurs in aberrant subclavian artery, which courses behind the trachea and pushes it forward in the lateral chest radiograph. You can see examples in case 213 of Caceres’ corner and Diploma cases 2, 9 and 84.
 
Final diagnosis: Probable aneurysm of the ductus arteriosus
 
Congratulations to S who was the first to think of the ductus in the plain film and made the diagnosis of ductus diverticulum after CT.
 
Teaching point: this is my first ductus aneurysm (if we are right) and I cannot have much to say. Perhaps to stress again the importance of looking at the aorto-pulmonary window in the PA radiograph.