Dr. Pepe’s Diploma Casebook: CASE 145 – Art of interpretation – SOLVED!

Dear Friends,

as I told you last week, my plan for September is to show interesting cases seen during this summer.

Today I have prepared an Art of Interpretation case that I saw in July. Radiographs belong to a 90-year-old man with cardiac arrhythmia.

Most likely diagnosis:
1. Aortic aneurysm
2. Duplication cyst
3. Thymic tumor
4. Any of the above

Leave your thoughts in the comments and come back on Friday to see the answer!

Click here to see the answer:

Findings: PA and lateral radiographs show a left superior middle mediastinal mass adjacent to the aortic knob (A and B, white arrows). Healed fractures of the right clavicle and second left rib are visible (A, red arrows). Pacemaker in the left hemithorax.

Analysis of relevant findings:

1. Left middle mediastinal mass adjacent to the aortic knob
2. Old fracture right clavicle
3. Old fracture second left rib

Summing up the findings: Although the appearance of the mediastinal mass is non-specific, the proximity to the aortic arch raises the possibility of an aortic aneurysm.
The bone fractures indicate previous trauma. Especially relevant is the fractured second rib. The first and second ribs are well protected by the thoracic cage and breaking either of them needs a strong impact, significant enough to shear the thoracic aorta and lead to pseudoaneurysm formation.

Therefore, our tentative diagnosis should be traumatic pseudoaneurysm of aorta, followed by a request for enhanced CT to confirm the diagnosis.

MEDIASTINAL MASS ADJACENT TO THE AORTIC KNOB + FRACTURED SECOND RIB = TRAUMATIC AORTIC PSEUDOANEURYSM.

Enhanced CT confirms a partially thrombosed aneurysm with a connection to the inferior aspect of the aortic arch (A-C, red arrows). On questioning, the patient mentioned an automobile accident fifteen years earlier. Because of his age, it was decided to control the aneurysm in six months’ time.

Final diagnosis: traumatic aortic pseudoaneurysm

Rupture of the thoracic aorta is not uncommon in severe blunt trauma, usually after high impact accidents or falls from a height of more than three meters (see case 1, below). About 85% of affected patients die immediately. The remaining 15% may survive if they arrive to the hospital in time to be treated.

A small percentage of cases are overlooked and patients survive without treatment. Over time a pseudoaneurysm develops at the point of rupture, most commonly the aortic arch.
About half these cases are discovered in routine chest examinations because of the typical location of the pseudoaneurysm around the aortic arch. Another diagnostic tip is that the patients are usually younger than patients with atherosclerotic aneurysms (see Case 2).

Discovering signs of previous trauma facilitates the diagnosis, especially when the first or second ribs are affected. After a history of severe trauma is elicited, the diagnosis is confirmed with enhanced CT. The pseudoaneurysm is usually located in the inferior aspect of the aortic arch, distal to the origin of the left subclavian artery.

Traumatic aortic pseudoaneurysms are infrequent, but I have seen several cases during my professional life. I am showing two representative cases to familiarize you with their radiographic appearance.

CASE 1

Chest radiographs of a 75-year-old male tourist with chest pain . A peripherally calcified mediastinal mass is projected over the aortic knob in the PA radiograph (A, arrow). The lateral view shows that the mass arises from the inferior aspect of the aortic arch (B, arrow).

Coronal and sagittal enhanced CT images demonstrate a calcified aneurysm arising from the inferior aspect of the aortic arch (C and D, arrows), distal to the origin of the left subclavian artery (E, circle). On questioning, the patient mentioned surviving a helicopter crash six years earlier. A diagnosis of traumatic pseudoaneurysm was made. The patient returned to his country of origin and was lost to follow-up.

CASE 2

42-year-old man with vague chest symptoms. A chest radiograph from another center (unavailable) showed a mediastinal mass with peripheral calcification. CT scout view yields the same finding (A, arrow).

Enhanced CT shows a large calcified aneurysm distal to the origin of the left subclavian artery (B and C, arrows). The rest of the aorta is normal. The patient had experienced an automobile accident ten years earlier. Traumatic pseudoaneurysm was proven at surgery.


Dr. Pepe’s teaching points:

Tips to suspect a traumatic aortic pseudoaneurysm in the chest radiograph:

1. Mediastinal mass around the aortic arch

2. Signs of previous trauma, especially fractures of the first or second ribs.

18 thoughts on “Dr. Pepe’s Diploma Casebook: CASE 145 – Art of interpretation – SOLVED!

  1. Good morning!
    There is circular opacity that bulges the left and anterior contour of aortic arch. I also think the most probable is an aortic aneurysm.
    There are also old fractures of ribs on the left and of the right clavicula. No signs of recent trauma.

    Like

  2. There is a bulging opacity lateral and anterior from the aortic arch. The arch edges are well appreciated on AP image, this implies the mass is not in contact with the hilum and is, therefore, either anterior or posterior to it. It’s at the level of aortopulmonar window, so I would say oesophageal duplication cyst.

    Like

  3. ANTERIOR POSITION AWAY FROM THE OESOPHAGUS, DENY THE POSSIBILTY OF DUPLICATION CYST, SHARP CONTOUR WOULD ALSO DENY DIAGNOSIS OF THYMIC TUMOUR, UNLESS ITS A CYSTIC TUMOUR, SO ITS AN ANEURYSM VERSUS THYMIC CYST!

    Like

  4. Anterior mediastinal mass excludes duplication cyst.
    Well defined rounded contour excludes thymus tumor.
    Ultimately related to ascending aorta in lateral view….aortic aneurysm is a possibility

    Like

  5. There´s a bulge in the left lateral contour of the aortic arch. Because of its saccular morphology, its location (near isthmus), and the evidence of previous trauma (old clavicle and rib fractures), I’d consider a traumatic pseudoaneurysm.

    Like

  6. I am very proud of all of you that made the diagnosis of traumatic aneurysm and put two and two together! Part of the merit belongs to MG who mentioned the associated fractures 🙂

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.