Cáceres Corner Case – Vignette 238

Dear Friends,

Today I am showing a preoperative PA radiograph in a 72-year-old woman.

Diagnosis:

1. Aortic elongation
2. Aortic dissection
3. Aortic aneurysm
4. Any of the above

What do you see?

Click here to see the answer

Findings: the obvious finding is elongation of the descending aorta. Usually, the diameter of the aorta cannot be determined in the plain film because only the outer wall is outlined by lung air, whereas the medial wall is obscured by the mediastinal structures.

In this case, the tortuous lower aorta projects the medial wall against the lung, allowing to measure the aortic diameter, which is increased (A, red line).
In the other hand, the ascending aorta is not prominent. This a negative finding against aortic elongation, which should involve the whole thoracic aorta.
Therefore, answers 1 and 4 can be excluded. To differentiate between answer 2 and 3 an enhanced CT is needed.

Click here to see more images

Enhanced CT was done. Axial and sagittal images are shown.
What would be your diagnosis?

1. Type B aortic dissection
2. Aneurysm with thrombus
3. Any of the above

Click here to see the answer

Findings: enhanced axial and coronal CT show a normal ascending aorta and a partially thrombosed dilated descending aorta. The fact that the outer wall is calcified (B-C, arrows) indicates that the intima is not displaced and rules out an aortic dissection. The correct diagnosis is aneurysm with partial thrombosis.

Final diagnosis: unsuspected aneurysm of descending aorta

I saw this case three days ago and thought it was a nice demonstration of a negative finding (lack of dilatation of ascending aorta) as mentioned in my last webinar.
As a result of the findings in the plain film, an enhanced CT demonstrated a partially thrombosed aneurysm and the patient was referred for vascular surgery.

This is the last vignette of the season. Since the pandemic is abating, I will resume next week the usual Caceres’ corner cases and Diploma presentations.

Cáceres Corner Case 236 – Vignette

Dear Friends,

Today’s radiographs belong to a 65-year-old woman with back pain. She was operated for myxoid liposarcoma of the lower limb seven years ago.

Do you see any abnormality?
If so, where is it?

1. Upper area
2. Middle area
3. Lower area
4. I don’t see it

Click here to see the answer

Findings: PA radiograph shows a double contour of the aortic knob (A, arrow) which indicates a superimposed mediastinal mass either in front or behind the knob. Lateral view shows increased opacity of the upper thoracic spine (B, circle), suggesting a posterior mass.

Click here to see more images

Unenhanced CT was done. What would be your diagnosis?

1. Neurogenic tumor
2. Metastasis
3. Neurenteric cyst
4. Any of the above

Click here to see the answer

Findings: coronal and axial unenhanced CT show a posterior mediastinal mass (C-D, arrows). Of the three possible diagnosis, I would choose neurogenic tumor/cyst, because they are frequent in the posterior mediastinum.

Click here to see more images

MRI was done. Would you change your diagnosis?

1. Neurogenic tumor
2. Metastasis
3. Neurenteric cyst
4. Any of the above

Click here to see the answer

Findings: MRI discovers that the vertebral body is affected (E-F, arrows). This makes neurogenic tumor unlikely. There are visible vessels within the mass, which excludes a cyst. Since myxoid liposarcomas metastasize to the spine, the best possibility is metastasis.
At surgery, a metastatic focus from liposarcoma was found.

Final diagnosis: Metastasis from liposarcoma

This is an interesting case because in the PA radiograph the abnormality is partially hidden by the aortic knob and can be difficult to see (remember to use checklists!).

As a chest radiologist occupying the lower strata of the totem pole, I confess my profound ignorance of liposarcomas. Surfing the Internet I have discovered several papers that state that myxoid liposarcoma metastasizes frequently to the spine and that MRI is the method of choice to demonstrate vertebral metastases in these cases.
Now I can transmit my new-found knowledge to you.

Cáceres Corner Case 234 – Vignette

Dear Friends,

Today´s radiographs belong to a 48-year-old woman with aortic stenosis.

Most likely diagnosis:

1. Intrathoracic goiter
2. Aortic arch malformation
3. Neurogenic tumor
4. Any of the above

Click here to see the answer

Findings: PA radiograph shows a left mediastinal mass superimposed on the artic knob (A, arrow). The trachea is not displaced. In the lateral view the mass is in the anterior/middle mediastinum (B, arrows).
Regarding the diagnosis offered, the location excludes neurogenic tumor which usually arises in the posterior mediastinum. Intrathoracic goiter is a possibility, but the fact that part of it is the anterior mediastinum and that there is no tracheal displacement goes against this diagnosis. The location of the mass around the aortic knob plus knowing that the patient has aortic valve stenosis point to an aortic arch malformation.

Click here to see more images

Enhanced CT shows that the mass corresponds to a high aortic knob (C, arrow). An oblique view demonstrates the high knob (D, arrow) with a kink and angulation of the aorta representing the lower knob in the PA radiograph (D, red arrow).
My apologies for showing only 3-D images, but the CT was done during the lockdown and they are all I could get.
The patient has no collateral circulation. He had no systemic hypertension and no gradient across the zone of kinking.

Final diagnosis: aortic pseudocoarctation

Pseudocoarctation of the aorta occurs when the aortic arch originates from the 3rd arch, instead of the 4th. In this condition, the aortic arch is higher than usual, with a kinking at the union of the aortic arch and descending aorta, simulating aortic coarctation. Rib notching is absent and systemic hypertension is not present.
This is a rare condition is, but it is not unusual to see it in clinical practice.

To compensate for the lack of CT images in this case, I am showing another pseudocoarctation with similar findings (Fig 1).

Fig 1. PA chest radiograph shows a superior middle mediastinal mass (A, arrow), displacing the trachea. Mass is vaguely seen on the lateral view (B, circle). The most common diagnosis should be an endothoracic goiter but remember that a vascular structure should be always ruled out with enhanced CT.

Coronal CT demonstrates that the mass corresponds to a dilated aortic arch located higher than usual (C, arrow). On the oblique reconstruction, the high aneurysmatic aortic arch is well seen as well as the kinking at the junction with the descending aorta (D, red arrow).
Final diagnosis: aortic pseudocoarctation with aneurysm of the aortic arch.


Cáceres Corner Case 227 – Vignette

Dear friends, starting today I plan to show simple teaching cases (vignettes) hoping to ease the boredom of the confinement.
I will show two cases every week (Monday and Thursday). To make the presentation more agile the diagnosis will be included. If you get impatient all you have to do is press the answer button.

The first case is a routine control PA radiograph in a 67-year-old woman operated on for breast carcinoma three years ago.

Question: Do you suspect any bone metastasis?

Click here to see the answer

Findings: There is an apparent lytic lesion in the distal end of the right clavicle (A, arrow), better seen in the cone down view (B, arrow).

When I saw this case two months ago, I could not determine whether the lesion was real or not. What would you do?
 
1. Compare with previous films
2. Call the oncologist
3. PET-CT
4. Bone scintigraphy

Click here to see the answer

In my opinion, the first thing to do was comparing with previous films although
this brilliant idea was hampered by the technician placing the marker in top of the distal clavicle in two earlier radiographs (C-D).

What would you do now?
1. Bone scintigraphy
2. Call the oncologist
3. PET-CT
4. CT

Click here to see the answer

Since I was not sure about the lesion, I decided to call the oncologist to find out if she suspected any metastasis and if the patient had any pain in the right acromioclavicular area. The answer was negative. What would you recommend?

1. Bone scintigraphy
2. CT
3. PET-CT
4. Radiograph of the right clavicle

click here to see the answer

In my opinion the fastest way to clarify the diagnosis was to take a radiograph of both clavicles (with the left for comparison). The distal end of the right clavicle has a normal appearance and , since the patient had no local symptoms, no further studies were needed.

Final diagnosis: normal variant simulating pathology in an oncologic patient

I have seen several chest radiographs with apparent lytic lesion of the distal clavicle that turned out to be normal. It is described in the Atlas of normal variants by Keats. In this case I was doubtful because the patient had a carcinoma and the appearance of the lesion was ominous.
 
There are two teaching points in this case:
1. Talking to the referring physician is important to determine the management of findings.
2. A simple and inexpensive procedure clarified the diagnosis and avoided unnecessary additional studies.