Cáceres’ Corner Case 211 – SOLVED

Dear Friends,

Today I’m showing chest radiographs of a 50-year-old woman with cough and sputum production.

What do you see?

You will have more images on Wednesday.

Dear Friends,

showing today CT images of the patient. What do you see?

Click here to see the CT images

Click here to see the answer

Findings: PA chest shows a small right lung, with a triangular opacity occupying the lower lung (A, arrow). The right heart border is not seen. The trachea and mediastinum are displaced to the right. In the lateral view the lower opacity occupies the lower lung from front to back (B, arrows).
This appearance is typical of combined RLL and RML collapse (obliteration of right heart border) and the most likely diagnosis is an obstructing lesion in the intermediary bronchus.

Enhanced axial CT shows marked narrowing of the intermediary bronchus (C, arrow). A caudal image shows marked dilatation of mucous-filled bronchi (D, arrows). This appearance indicates a long-standing obstruction and goes against a malignant process

Comparison with a previous radiograph (F) shows that the chest has not changed in comparison with the recent one (E). Bronchoscopy performed three years earlier demonstrated chronic stenosis of intermediate bronchus secondary to previous TB

Final diagnosis: Chronic TB changes of intermediary bronchus causing collapse of RML and RLL.
 
Congratulations to Maged Shaban and Yelgha who made the correct diagnosis of RLL and RML collapse
 
Teaching point: remember that central lobar collapse with bronchiectasis is rarely caused by malignancy.

Musculoskeletal #4 – Long case

Regarding the following X-Ray:

Frontal x-ray of the right hand

Where is the lesion?

Metaphysis of the base of the fourth middle phalanx.

What are the radiological characteristics/findings?

Expansile lytic lesion (bubbly appearance) with narrow zone of transition, no cortical break through, and no soft-tissue component.

What is the differential diagnosis?

Enchondroma: Enchondromas have variable imaging appearances but are typically lytic lesions with non-aggressive features. They could show chondroid calcifications (rings and arcs calcification). But in the hands and feet they are typically purely lytic with no matrix.
Eosinophilic granuloma: It mainly involves the diaphysis and does not cross the growth plates. It appears as punched out lytic lesions without sclerotic rim.  Imaging appearance in the long bones depends on the phase of the disease which is imaged. It can look aggressive in the initial phase. In the healing phase it can show solid benign periosteal reaction.
Fibrous dysplasia.Usually shows ground-glass matrix but may be completely lucent or sclerotic. Well-circumscribed lesions with no periosteal reaction may lead to premature fusion of growth plates leading to short stature in the lower limbs and bowing deformities (Shepherd’s Crook deformity of the femoral neck)

What is the most likely diagnosis?

Diagnosis: Enchondroma

Regarding the diagnosis…

What are the associated syndromes with multiple enchondromas?

Ollier disease: multiple enchondromas are usually  confined to one side of the body and limited to the limbs. There is increased risk of chondrosarcoma 

Maffucci syndrome: multiple enchondromas with soft-tissue haemangiomas

Dr. Pepe’s Diploma Casebook – The art of interpretation – CASE 146 – SOLVED

Dear Friends,

Today I am presenting another “Art of interpretation case”, from last August.
Radiographs belong to a 22-year-old Spanish national with fever and dry cough for the last seven days. He had visited South Korea during the month of July. Chest radiographs read as normal by the Emergency Room physician.
What do you see?

More images will be shown on Wednesday.

Click here to see the images shown on Monday


Dear Friends,
showing several images of the enhanced CT.

What do you see?

Click here to see the new images

Click here to see the answer

Findings: PA radiograph shows convexity of the aortopulmonary window (A, white arrow) and increased opacity of the left hilum (A, red arrow). The lateral view shows a faint opacity projected over the middle third of the thoracic spine (B, circle) that was overlooked in the initial reading.
The convexity of the APW suggested mediastinal lymphadenopathy, and CT was performed.

Coronal enhanced CT shows an enlarged lymph node in the APW (A, arrow). Axial CT depicts enlarged lymph nodes in the left hilum (B, circle). Lung window demonstrates air-space disease in the apical segment of the LLL (C, arrow), which explains the posterior faint opacity in the lateral view.

Summary of CT findings:

– Unilateral enlarged hilar lymph nodes
– Lymph node in APW
– Air-space disease in the apical segment of LLL

The most significant finding is the presence of unilateral hilar lymph nodes which have a limited differential diagnosis: in the great majority of patients they are due either to lung carcinoma or active tuberculosis. As this particular patient is 27 y.o., carcinoma is unlikely. Therefore, our tentative diagnosis should be active TB, which is also supported by disease in the apical segment of the LLL, a common location for TB.

The patient was placed in isolation, bronchoscopy was performed, and Mycobacterium tuberculosis was found in the aspirate.

Final diagnosis: active tuberculosis

YOUNG PERSON + UNILATERAL ENLARGED HILAR LYMPH NODES + PULMONARY INFILTRATE IN APICAL SEGMENT OF LLL = ACTIVE TUBERCULOSIS

Active pulmonary tuberculosis is not uncommon, and the chest radiograph plays an important role in its detection. Findings that help to suspect TB in the plain film are:

Location of the parenchymal disease. Involvement of the apices or the apical segment of either lower lobe should raise the possibility of a tuberculous infiltrate, although TB can affect any area of the lung.

Cavitation. The presence of cavities within a pulmonary infiltrate suggest tuberculosis or necrotic pneumonia.

Visible lymphadenopathies. Tuberculous lymph nodes are usually unilateral and located in the hilum and homolateral mediastinum. In about one third of patients they are bilateral. In such cases, lymphoma and sarcoidosis, among others, should also be considered.

CT refines these parameters by discovering cavitation or lymphadenopathy that is not evident in the plain film. The presence of low-attenuation lymph nodes due to caseous necrosis is highly suggestive of TB, although it is not pathognomonic. Other conditions can also show these features. However, normal-density lymph nodes do not exclude TB, as was seen in the present case.

Below, I show a few nice images of active TB in which low-attenuation lymph nodes
suggested the correct diagnosis.

CASE 1

23-year-old woman with cough and low-grade fever. Chest radiographs shows air-space disease in the RLL (A and B, white arrows). There is obvious widening of the right paratracheal line (A, red arrow), indicating mediastinal lymphadenopathy.

Enhanced axial CT confirms the RLL disease which is non-specific (C, arrow). No cavitations are visible. The mediastinal window shows numerous enlarged lymph nodes, some with a hypodense center (D and E, arrows) and others with peripheral enhancement (ring sign) (F, arrows).

Abdominal CT also shows enlarged mesenteric lymph nodes with the ring sign (G and H, circles).

It is interesting to note that lower lobe TB occurs in only 5% of patients. In this particular case the diagnosis of TB was suggested by the CT appearance of the affected lymph nodes. Mycobacterium tuberculosis was recovered from sputum.

Final diagnosis: active TB


Dr. Pepe’s teaching points:

1. Think of TB in unilateral hilar adenopathy in a young person.

2. Low-density lymph nodes on CT are highly suggestive of active TB, although normal-density nodes do not exclude it.

Emergency #14 – Flashcard

18-years-old male:
* Rigid abdomen and generalised tenderness
* Pain lower abdomen
* CRP 250

What do you see? Perforated appendicitis? What is your diagnosis?

Diagnosis Perforated sigmoid diverticulitis (Hinchey 3 or 4, peritonitis)

> Mesenterial fatty infiltration, free air bubbled outside bowel lumen.
> Also subdiaphragmal free air and free fluid.
> Notice enlarged reactive lymph nodes and peritoneal thickening and enhancement, indicative of peritonitis.
> Patient was operated, free faeces was found in the abdomen.

Hinchey classification of acute diverticulitis:
* Stage 1a: phlegmon
* Stage 1b: diverticulitis with pericolic or mesenteric abscess
* Stage 2: diverticulitis with walled off pelvic abscess
* Stage 3: diverticulitis with generalised purulent peritonitis
* Stage 4: diverticulitis with generalised faecal peritonitis

Cáceres’ Corner Case 210 – SOLVED

Dear Friends,

showing another case seen during this summer. Preoperative chest radiography for knee surgery in a 57-year-old man. More images will be shown on Wednesday.

What do you see?

New images are shown:

Click here to see more images

Click here to see the answer

Findings: PA radiographs shows a right mediastinal mass at the level of the tracheal bifurcation (A, arrow), which has not changed significantly in comparison with a chest film taken for pneumonia one year earlier (B, arrow).

Several of you have mentioned a triangular shadow at the right cardiophrenic angle
(A-B, red arrows). This appearance should suggest paracardial fat pad as the first choice.

The differential diagnosis of a right mediastinal mass at the level of the tracheal bifurcation is simple: most of the times it is either an enlarged azygos vein or lymphadenopathy.
 CT shows a dilated azygos vein with a prominent azygos arch (C-D, arrows), suggesting a impeded blood flood either in the inferior or superior vena cava. Considering that the patient is asymptomatic, the most likely diagnosis is congenital interruption of the inferior vena cava, with azygos continuation. The diagnosis is confirmed noting the absence of the suprarenal portion of the IVC (C, circle) and the association of other congenital anomalies, such as polisplenia (C, red arrows) and abnormal bifurcation of the bronchial tree (E, arrows).

Coronal CT confirms that the triangular paracardial shadow represents paracardiac fat.

Final diagnosis: Congenital absence of IVC with azygos continuation
 
Congratulations to MK, who made a late (and accurate) diagnosis of prominent azygos vein
 
Teaching point: remember that the most common right lower paratracheal masses are either an enlarged azygos vein or mediastinal lymph nodes.

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.