Musculoskeletal #17 – Long Case

2-year-old girl, referring to emergency department after a fall.

What do you see?

Click here to see the answer

– An expansile lytic lesion with ill-defined margins (green arrow) is seen on the diaphysis of fibula.

– Lamellated periosteal reaction (red arrow) suggests an aggressive lesion.

Differential diagnosis of an aggressive lytic lesion in a 2-year-old child includes:
– Osteomyelitis
– Ewing’s sarcoma
– Langerhans cell histiocytosis
– Leukemia/lymphoma

What should be done next?

An MRI scan

Intramedullary hyperintense lesion with extensive surrounding soft tissue and bone marrow edema on coronal STIR image (a) is seen. The lesion is hypointense on T1 WI (b).

Cortical destruction is shown on axial PD image (arrow in c).

Postcontrast coronal (a) and axial fat-suppressed (b) T1-weighted images show extensive enhancement in the lesion and the surrounding soft tissue

Histopathologic examination revealed Langerhans cell histiocytosis.

Langerhans Cell Histiocytosis (LCH)

– LCH is characterised by idiopathic infiltration and accumulation of abnormal histiocytes within various tissues.

– Bone is the most commonly affected tissue in children, with a predilection for axial bones, and femur is the most commonly affected long bone.

– Radiographic appearance of the lesions depends on the site of involvement and the phase of the disease.

Skull: Calvarium is more affected than the skull base, typically seen as single or multiple well-defined lytic lesions on radiography; T1 hypointense, T2 hyperintense with significant enhancement on MRI. Temporal bone is the most common affected part of skull base seen as destructive lesions with a soft tissue component.
Spine: Vertebral bodies are affected with relative sparing of posterior elements. A typical vertebra plana appearance may be encountered with total collapse.
Long bones: Ill-defined lytic lesions with/without cortical destruction are seen usually located at diaphysis or metaphysis. Periosteal reaction may be present. Extensive bone marrow and soft tissue signal changes on MRI may also be helpful in the diagnosis.

Cáceres’ Corner Case 254 – SOLVED

Dear Friends,

today’s radiographs belong to a 34-year-old woman with moderate cough. Previous history of asthma.

What do you see?

Diagnosis:

1. Mucous plug
2. Segmental atelectasis
3. Tuberculosis
4. None of the above

Click here to see the answer

Findings: Pa chest radiograph shows a tubular opacity that seems to arise from the right hilum (A, arrow). The lateral chest (B) does not show any abnormality, which raises the possibility that the opacity in the PA view is spurious.

Careful inspection demonstrates that the opacity extends to the right apex and to the neck (C, red arrows). The appearance is typical of a superimposed pigtail.

Some of you described the slightly elevated minor fissure. It is an unfortunate coincidence, probably related to previous episodes of mucous plug in an asthmatic patient causing mild loss of volume of RUL.
 
Final diagnosis: Pigtail simulating pulmonary disease.
 
Congratulations to MK who was the only one to suggest the correct diagnosis.
 
Teaching point: You may think that I tricked you, but it was not my intention. This case is a reminder that apparent pulmonary opacities may be located in the pleura, chest wall or outside of the body.
 
To emphasize this point I am showing two more cases of braids simulating pulmonary disease, presented in earlier blogs.

CASE 1. 48-year-old woman with mild cough. PA radiograph shows an ill-defined opacity in the left lung, running from top to bottom (A, white arrows). The opacity extends towards the neck (A, red arrow), which suggests that it is external to the lung. Lateral view shows an elongated opacity in the back of the chest (B, arrows).

A photo of the patient (C) confirms that a long braid is the cause of the opacity. PA radiograph after lifting the braid demonstrates that the chest is normal (D).

CASE 2. 25-year-old man with braided hair simulating a RUL infiltrate (A, arrow). The opacity extends to the neck, giving away the diagnosis (A, red arrow). After raising the braid, the chest looks normal (B). Remember that men also wear their hair long nowadays.

Neuroradiology #25 – Flashcard

What do you see? What is the most likely diagnosis?

Click here to see the answer

Multiple sclerosis

Multiple white matter lesions involving the corpus callosum, peri-trigone region, subcortical, and deep white matter.
Ddx: other demyelination, vasculitis, small vessel disease, tosic/metabolic, watershed infarcts.  

Dr. Pepe’s Diploma Casebook 169 – SOLVED

Dear Friends,

Presenting a new case of “Big little findings”. Preoperative chest radiograph for meniscus surgery in a 56-year-old woman.

What do you see?

Click here to see the answer

Findings: PA view shows a small right hemithorax. There is elevation of the right hemidiaphragm and a small hilum (A, red arrow). The findings are very suggestive of RLL lobectomy. The oblique fissure in the RLL represents the displaced minor fissure (A, white arrow). Previous CT shows a normal-size right lung with a ground-glass opacity in the RLL (B, arrow).

Final diagnosis: RLL lobectomy for adenocarcinoma of the lung

I am showing this case to discuss displacement of the lung fissures, an important finding that can indicate partial collapse of the underlying lobe. Usually, lobar collapse is detected because of the increased opacity of the lobe. Occasionally, the collapsed lobe retains much of its air, so a shift of the fissure may be the only sign of collapse.

A potential pitfall of fissure displacement is previous surgery, as seen in the case presented. In my experience, excluding previous surgery, aerated lobar collapse occurs mainly in the following conditions:

1. Inflammatory peripheral lung disease
2. Central lobar bronchial obstruction
3. Rounded atelectasis

NORMAL ANATOMY
The right minor fissure is visible in about 50% of chest radiographs as a straight horizontal line at the level of the right hilum (Fig. 1, A and B) The right and left major fissures are not visible in the PA film because their course is not tangential to the x-ray beam. (A, curved dotted lines). They are both visible as oblique lines in the lateral view (B).

Fig. 1
Fig. 2. PA radiograph showing the minor fissure (A, arrow). The lateral view shows both the right minor and major fissures (B, white arrows) and the upper portion of the left major fissure (B, red arrow)

Inflammatory lesions can cause scarring which diminishes the size of the affected lobe. TB is the most common cause in upper lobes. Bronchiectasis is the predominant cause in lower lobes. Both conditions can show an aerated lobe with loss of volume (Figs. 3-5).

Fig. 3. 68-year-old woman with previous history of TB. There is aerated partial collapse of RUL as evidenced by the elevated minor fissure (A and B, white arrows). Fibrotic changes are seen in the apex (A and B, red arrows). An incidental finding is calcification of breast prostheses.
Fig. 4. RLL collapse secondary to bronchiectasis. There is an oblique line at the right base (A, white arrow) that simulates an inferior accessory fissure. However, the right hilum is markedly low (A, red arrow), indicating loss of volume of RLL. Coronal CT shows marked RLL collapse with bronchiectasis, outlined by the displaced major fissure (B, arrow).
Fig. 5. 56-year-old man with previous TB. Lateral view shows forward displacement of the left major fissure (A, arrows), indicating partial collapse of LUL. PA radiograph depicts marked elevation of left hilum (B, arrow), secondary to fibrotic TB.

Central lobar bronchial obstruction is occasionally associated with aerated lobar collapse. It is thought to be due to collateral air ventilation through incomplete fissures (Figs. 6-7).

Fig. 6. Routine follow-up of an 82 y.o. man who underwent surgery for laryngeal carcinoma 10 years ago. PA view shows abnormal left hilum and blurring of the left cardiac contour (A, arrow). Lateral view shows marked forward displacement of the left major fissure (B, arrows) indicating severe LUL collapse.

Unenhanced axial CT confirms the marked LUL collapse (C, white arrow) secondary to endobronchial obstruction (C, red arrow). CT taken one year earlier shows an endobronchial lesion (D, red arrow) and discrete forward displacement of the major fissure (D,E, white arrows). These changes were overlooked. Surgical diagnosis: bronchogenic carcinoma

Fig. 8. Aerated RLL collapse in central carcinoma. PA radiographs shows a very low right major fissure (A, red arrow), better depicted in the cone down view (B, arrow). The left hilum is descended (A, white arrow). Bronchoscopy discovered a carcinoma of the RLL bronchus. The oblique line in the RUL corresponds to a scar.

Rounded atelectasis is a common cause of fissure displacement. It occurs secondary to spiral folding of the lung parenchyma when fixed by thickened pleura. The consequence is a peripheral rounded opacity in an aerated collapsed lobe. The volume loss, detected by the displaced fissure, avoids possible confusion with a true nodule in the plain film.

Fig. 9. Asymptomatic 49-year-old man with rounded atelectasis. Notice the visibility of the left major fissure, indicating LLL volume loss (A, arrows). Lateral view shows an ill-defined posterior opacity which corresponds to the rounded atelectasis (B, arrow).

Axial and sagittal CT confirm displacement of the left major fissure (C and D, white arrows), the small LLL, and the posterior rounded atelectasis (C, red arrow).

As a final thought, occasionally you may find fissure displacement without an apparent cause (Fig. 10).

Fig. 10. 92-year-old man, asymptomatic. PA radiograph shows downward displacement of the minor fissure (A, white arrow), major fissure (A, yellow arrow) and right hilum (A, red arrow). In a previous film four years earlier, the minor fissure (B, yellow arrow) and the right hilum (B, red arrow) were moderately descended. Since the patient was 92 y.o. and had no symptoms, his physician decided not to do a CT scan. My impression is that he has fibrotic changes in the RLL, which is not unusual in advanced age.


Follow Dr. Pepe’s advice:
1. A displaced fissure may be the only manifestation of aerated lobar collapse (always exclude previous surgery).

2. Most common causes:

a) Peripheral lobar inflammatory disease

b) Central bronchial obstruction

c) Rounded atelectasis

Musculoskeletal #16

63-year-old patient with knee pain. What do you see?

Click here to see the answer

IMAGING FINDINGS

Lucent distal femur epiphyseal lesion with thin sclerotic borders and rings-and-archs calcifications, characteristic of chondral matrix

What is the most likely diagnosis?

Enchondroma

CASE 2

Malignant counterpart chondrosarcoma in spinous process of lumbar spinal vertebra

What do you see?

Click here to see the answer

Teaching points

Enchondroma
Characteristic findings: location epiphysis, thin sclerotic borders and rings-and-archs calcifications
It might be indistinguishable from chondrosarcoma on imaging, and pain may raise the latter suspicion
If bone aggressive lysis, striking endosteal scalloping or soft tissue component is present,

Cáceres’ Corner Case 253 – SOLVED

Dear Friends,

Today’s case is a PA chest radiograph for knee surgery in a 28-year-old man.

What do you see?

Click here to see the answer

Findings: PA chest radiograph shows an osteochondroma in the right humerus (A, yellow arrow). There are two more in the anterior arch of the left fifth rib and in the proximal end of the right clavicle (A, red arrows).
They are better seen in the cone down views (B-D, arrows).

The first and only diagnosis that comes to mind is multiple osteochondromatosis, confirmed with views of the lower extremities (E-G).

Final diagnosis: Multiple osteochondromatosis.
 
Most of you did very well in this case. Congratulations to Mauro, who was the first and to Kaushalya and Ali who made back-to-back diagnosis in a five-minute interval.
 
Teaching point: remember to look at the bones of the chest, especially when taking an examination. It may surprise the examiner and win you a few extra points.

Dr. Pepe’s Diploma Casebook 168 – Solved!

This week’s case is a little special! Prof. Cáceres has prepared a Quiz that will to challenge your knowledge and your speed reviewing radiographs! The quiz contains 7 different cases with radiographs and you will have 60 seconds to answer each question! The three participants with highest score will receive a signed picture of Dr. Pepe 😀

Are you up for the challenge? Join the quiz here It will start on Thursday 18th, at 12:00 CET.

On Friday Prof. Cáceres will publish the explanation for each case on the blog.

CASE 1

CASE 1

71-year-old man with hemoptysis:

In which quadrant will you place the lesion?

1. Right upper quadrant
2. Right lower quadrant
3. Left upper quadrant
4. Left lower quadrant

Click here to see the answer

Findings: there is a rounded opacity behind the heart (A, arrow). CTs show a non-enhancing pulmonary mass with irregular borders attached to the pericardium (B-C, circles).
Post-operative diagnosis: mucoid carcinoma of the lung.


CASE 2

CASE 2


43-year-o.ld male with moderate cough.

Most likely diagnosis:

1. Tuberculosis
2. Enlarged left pulmonary artery
3. Carcinoma
4. Any of the above

Click here to see the answer

Findings: PA radiograph shows that the left hilum is larger and more opaque than the right one (A, arrow). The pulmonary arch is prominent (A, red arrow). The lateral view shows an enlarged left pulmonary artery (B, arrows) excluding the diagnosis of carcinoma or TB as causes of hilar enlargement. Enhanced axial CT confirms the enlarged left pulmonary artery (insert, arrow).
Diagnosis: Congenital pulmonary valve stenosis with secondary dilatation of the left pulmonary artery due to the jet effect.

CASE 3

CASE 3


60-year-old man with chest pain.

In which quadrant will you place the lesion?

1. Right upper quadrant
2. Right lower quadrant
3. Left upper quadrant
4. Left lower quadrant

Click here to see the answer

Findings: there is a well-defined rounded left apical opacity (A, arrow), better seen in the cone down view (B, arrow)

Coronal and axial enhanced CT confirm the apical mass (C-D, arrows). The patient complained of pain in the left shoulder. Needle biopsy came back as adenocarcinoma.

Final diagnosis: Pancoast tumor

CASE 4

CASE 4

65-year-old man with cough and dyspnea

Diagnosis:

1. Unilateral hyperlucent lung
2. Pneumothorax
3. Giant bulla
4. Carcinoma of the lung

Click here to see the answer

Findings: the initial impression of the PA chest is a left hyperlucent lung with diminished vascularity. A second look shows a descended left hilum (A, arrow) and a concave paraspinal line (A, red arrow) representing the major fissure. These findings are indicative of LLL collapse with compensatory expansion of LUL.

 
Enhanced axial CT confirms the marked LLL collapse (B, arrow). Coronal reconstruction shows irregular bronchial narrowing (C, red arrow) with complete occlusion of the LLL bronchus.

Diagnosis: epidermoid carcinoma with LLL collapse.

CASE 5

CASE 5

33-year-old man with pain in the right hemithorax

Where is the nodule located:

1. Lung
2. Pleura
3. Chest wall
4. Need a CT

Click here to see the answer

Findings: PA radiograph shows a rounded opacity in the lower right chest (A, circle) with incomplete border sign (medial aspect outlined by air, lateral border not visible because in contact with chest wall). The clue to its location is given by the rib erosion (A, red arrow) which places the lesion in the underside of the rib. The border of the erosion is sclerotic, indicating a slow-growing process.
CT confirms a soft-tissue mass (B, circle) and the rib erosion (B-C, red arrows).

Final diagnosis: neurofibroma in a patient with neurofibromatosis.

CASE 6

CASE 6


32-year-old man with chronic cough

In which quadrant will you place the lesion?

1. Right upper quadrant
2. Right lower quadrant
3. Left upper quadrant
4. Left tower quadrant

Click here to see the answer

Findings: PA radiograph shows increased lucency of the lower right lung with decreased vasculature (A, circle). This finding has two main causes: increased lung air or paucity of lung vessels (pulmonary embolism, arterial stenosis). In these cases, the best approach is to take an expiratory film, which will demonstrate whether or not there is air-trapping. If present, it will orient us to a bronchial obstructive process, either central or peripheral

Coronal CT (B) confirms the increased lucency and diminished vasculature of RLL and RML. Scattered bronchiectasis are seen within the lucent lung (B-C, arrows).
Axial expiratory CT (D) demonstrates marked air-trapping of RML and RLL.

The patient had a history of swallowing a peanut at the age of five years, developing RLL pneumonia at that time. Control radiographs demonstrated increased lucency of the lower right lung over the years.
 
Final diagnosis: Lobar Swyer-James/McLeod syndrome secondary to aspiration of a peanut in childhood.


CASE 7

CASE 7


17-year-old woman with moderate cough

Most likely diagnosis:

1. Benign pulmonary nodule
2. Arteriovenous malformation
3. Pleural plaque
4. Artifact

Click here to see the answer

Findings: PA radiograph shows a rounded opacity in the periphery of the left lung (A, arrow) that seems to be calcified. Cone down view shows a whorled pattern (B, arrow). A braid is visible in the left supraclavicular area (A, red arrow).

Scout view of the CT does not show the apparent lung lesion, which is not visible in the axial view of the lung (D). The technician that did the CT noticed that the patient had a long braid with a rubber band at the end.

Final diagnosis: hair braid simulating a lung nodule.

Head and Neck #4 – Flashcard

CT – Coronal + C
CT – Axial + C
Where is the abnormality?​

Left side of the neck.

How can the abnormality be described?​

Multiple enlarged neck clustered lymph nodes, with some of them showing necrosis.

What is the differential diagnosis?

Infectious lymphadenitis: such as TB or pyogenic lymphadenitis.
Metastasis: particularly from head and neck malignancies.
Treated lymphoma or lymphoma in immune compromised patient.

What is the final diagnosis

TB lymphadenitis

Emergency #26 – Flashcard

A 30-year-old female with right shoulder pain.

4 images of the right shoulder were obtained (axillar, Y-view, internal rotation, external rotation)

Click here to see the images
Y-view

Internal rotation
External rotation
Findings:

Findings


Right shoulder: There is a nondisplaced fracture involving the inferior aspect of the glenoid, with involvement of the articular surface. Glenohumeral joint shows normal alignment. Acromioclavicular joint is normal. No soft-tissue calcification. No fracture or dislocation

What is the most likely diagnosis?

The most likely diagnosis is Hill-Sachs lesion

Hill-Sachs lesions are a posterolateral humeral head compression fracture. Typically occurs secondary to recurrent anterior shoulder dislocations. It is often associated with a Bankart lesion of the glenoid

Internal Rotation
External Rotation

These lesions are best seen following relocation of the joint. It appears as a sclerotic line running vertically from the top of the humeral head towards the shaft. A wedge defect may be evident in large lesions. The lesions are better appreciated on internal rotation views