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 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.

Cáceres’ Corner Case 248 – SOLVED

Dear Friends,

today I am showing preop radiographs for knee surgery of a 71-year-old man.
What do you see?

More images will be shown on Wednesday.

Click here to see new images

Dear friends, showing additional images of the sternum taken six years earlier, in 2014.
What do you think?

Click here to see the answer

Findings: PA chest is unremarkable (A). The lateral radiograph shows an expanding lytic lesion in the sternal manubrium (B, circle).

Cone down view shows the lesion better (C, arrows). Sagittal, coronal and axial unenhanced CT taken six years earlier (2014) demonstrate that the cortical bone is broken in several places, suggesting an aggressive process (D-F, arrows). A soft-tissue mass is not visible.

No other skeletal lesions were found. Biopsy of the sternum confirmed the diagnosis of solitary myeloma (plasmocytoma), that was subsequently treated. The patient remained asymptomatic.
 
Final diagnosis: Plasmocytoma of the sternum
 
Congratulations to Priyanka Chhabra and Olena, who made the correct diagnosis. And kudos to all of you who saw the lesion in the lateral chest radiograph.
 
Teaching point: Remember that a lytic lesion of the sternum in an adult is malignant until proven otherwise. Main etiologies are primary tumors (chondrosarcoma) and metastases.

Reviewing the literature, I found a case report with similar findings: Solitary plasmacytoma of the sternum with a spiculated periosteal reaction: A case report. ONCOLOGY LETTERS 9: 191-194, 2015

Cáceres’ Corner Case 246 – SOLVED

Dear Friends,

Today I am showing the PA radiograph of an 82-year-old woman. Preoperatory for cataracts.

What do you think about the right hilum?

1. Calcified TB nodes
2. Sarcoidosis
3. Amyloid
4. None of the above

More images will be shown on Wednesday.

Click here to see the images shown on Monday


Dear friends, showing today PA and lateral radiographs taken two years earlier. Hope they help.

Click here to see the new images

Click here to see the answer

Findings: Initial PA radiograph shows opacities in the right hilum (A, circle), unchanged in comparison with a previous film taken two years earlier (B, circle).

The clue to the diagnosis lies in the density and appearance of the opacities. They are denser than the typical lymph node calcifications, suggesting that they are metallic. In addition, some of them look tubular or branching (C, red arrows). A lateral view taken two years earlier confirms dense lineal and branching opacities in right lung (D, arrows).
The combination of linear and branching metallic opacities suggests that they are either in the bronchi (previous bronchography) or within the pulmonary vessels (embolism after vertebroplasty o treatment of AV malformation). See Diploma # 44.

Lateral view of the lumbar spine shows surgical changes with vertebroplasty of L3 to L5 and leakage of the cement into the epidural veins (E, arrows), better seen in the sagittal CT (F, arrows).

Unenhanced CT confirms multiple cement emboli in the pulmonary arteries (G-J, circles)

Final diagnosis: cement embolization of the lung after vertebroplasty
 
I must mention Olena and Ayudi who suggested amyloid and broncholithiasis but failed to notice the metallic opacity of the findings.
 
Teaching point: Consider previous vertebroplasty when you see metallic opacities in the lungs. It is a common complication.

Dr. Pepe’s Diploma Casebook 161 – Meet the examiner

Dear Friends,

This week’s case follows the pattern of a “Meet the Examiner” presentation, with questions and answers similar to a real examination. Take your time before scrolling down for the answer.

The images belong to a 60-year-old man with moderate cough and dyspnea

What would you recommend?

1. Compare with previous films
2. Chest CT
3. PET-CT
4. None of the above

Click here to see the answer

Findings: PA radiograph shows large bullae in both upper lobes. There is a nodule in the RUL projected over one bulla (A, arrow). Two small calcified granulomas are visible in the periphery of the LUL (A, circle). PA film taken five years earlier (B) does not show any nodule in the RUL. The granulomas in the LUL are unchanged.

Report of the chest : bullous emphysema with a nodule not visible in 2014. Given the relationship between bullous disease and carcinoma, it is imperative to do a chest CT.

Enhanced CT was done the next day. What would you suggest?

1. Antibiotic treatment and CXR in one month
2. PET-CT
3. Antibiotic treatment and CT in one month
4. None of the above

Click here to see the answer

Findings: aside form large bullae in both upper lobes, an irregular nodule is evident in the RUL (A-B, arrows). In my opinion, given the appearance of the nodule I would suspect malignancy and request a PET-CT. However CT was reported as: Pseudonodular opacity in RUL that could be related to an infectious/inflammatory process. A neoplasm cannot be excluded. Recommend control after treatment

Click here to see more images

A chest radiograph was taken one month later.
What would you do?

1. PET-CT
2. CXR in three months
3. CT in three months
4. Control in one year

Click here to see more images

The chest radiograph one month later was reported as unchanged and no further suggestions were made by the radiologist. The clinician took no further action.

The patient came back ten months later, and a new radiograph showed an obvious increase in size of the nodule (B, arrow) when compared to the initial film (A, arrow)

Click here to see more images

Enhanced CT confirms the increase in size of the nodule (A-B, arrows). Surgery discovered a carcinoma in the wall of a bulla.

Final diagnosis: adenocarcinoma of the lung associated to bullous disease.

Lung carcinoma seems to occur more often in bullous disease, although there is not enough evidence compiled at the present time. Despite the lack of evidence, knowing
this association may prevent misdiagnosis.
A lesser known fact is that the cystic space may disappear after the carcinoma develops, as occurred in a second case (see below). Spontaneous regression of a bulla may be due to non-malignant causes, but carcinoma should be excluded with CT because it may take years for the lesion to be visible in the chest radiograph.

I am showing this case because the opinion given in the chest radiograph was unequivocal, whereas the CT report was vapid, giving the impression that the nodule was infectious, and that malignancy was less likely. The follow-up radiograph was disregarded by the radiologist and clinician and this caused a delay in diagnosis of almost one year.

To complete the information, I am showing a second case of carcinoma developing in the wall of a cystic space

Images of the second case were obtained during routine CT screening in a 72-year-old man, heavy smoker.
Apical axial CT image shows a small nodule in the LUL (A, arrow), with increased uptake on PET-CT (C, arrow). There is a cystic airspace in the LLL (B, arrow) with no PET-CT uptake, interpreted as a non-specific cystic airspace lesion.

At surgery a carcinoma of the LUL was found.

It was decided to continue with yearly follow-up studies. The cystic air space (A, arrow) increased in size in 2008 but still had a thin wall (B, arrow). In 2009 it has decreased slightly in size and the wall is thicker than the previous year (C, arrow). A new PET-CT shows increased uptake in the posterior wall (D, arrow).

Malignancy was suspected. The patient refused further surgery or percutaneous biopsy and it was decided to do a follow up study three months later.
Axial CT shows that the cystic airspace has disappeared and in its place, a solid mass has developed (A and B, arrows) with increased overall uptake on PET-CT (C, arrow). At surgery, an adenocarcinoma was found.

Final diagnosis: adenocarcinoma arising in the wall of a cystic airspace, which disappeared as the tumour progressed.


Follow Dr. Pepe’s advice:

1. Bullous emphysema and isolated cystic spaces may be associated with an increased incidence of carcinomas

2. A poorly worded report may cause an unnecessary delay in diagnosis

Cáceres’ Corner Case 245 – SOLVED

Dear friends, Dr Pepe has eloped with Miss Piggy (again) and has let me alone, holding the fort. Hope he will be back in time to give the next webinar.

Today’s radiographs belong to a 60-year-old male with cough and moderate dyspnea.

Diagnosis:

1. Hilar lymphadenopathy
2. Right pulmonary artery aneurysm
3. Mediastinal tumor
4. None of the above

Click here to see the answer

Findings: PA and lateral chest radiographs show a right hilar mass (A-B, arrows). In my opinion, the appearance of the mass and its location in the right hilum in the lateral view rules out a mediastinal mass.
There is a small nodule in the RUL (A, red arrow) that can be overlooked unless we look for it

The nodule is better seen in the cone down view and the axial CT (C-D, red arrows), with high SUV in the PET-CT (E, arrow), accompanied by a metastatic node in the mediastinum (E, circle).

Caudal slices of enhanced CT show multiple lymph nodes in right hilum (F, arrow) and mediastinum (G, circle).

Biopsy of a lymph node returned as metastatic carcinoma.

Final diagnosis: carcinoma of the lung with mediastinal metastases

Congratulations to archanareddyt who was the only one to discover the RUL nodule

Teaching point: this is an interesting case for educational purposes.
1. Knowing the most common causes of unilateral hilar enlargement (lymph nodes vs. enlarged artery) helps the differential diagnosis.
2. We should think of common processes rather than unusual ones (lymph nodes vs. aneurysm).
3.  Suspecting unilateral hilar lymph nodes leads to search for the two more common etiologies (TB or carcinoma) leading to the discovery of the RUL nodule.

Hope the case was useful!

Neuroradiology #24 – Flashcard

89-year-old female patient with aplastic anemia. Showing CT images without contrast media. What do you see?

Click here to see the answer

CT images without contrast media: Subacute isodense right subdural hematoma, revealed with narrowing of right cerebral hemispheric sulci and right lateral ventricle and minimal midline shift (red arrows), acute left subdural hematoma (blue arrow)

Dr. Pepe’s Diploma Casebook 160 – With a webinar! – SOLVED

Dear friends, I am starting a new webinar series entitled “Things that we already know, but are important to remember”. The objective is to refresh basic concepts that often are forgotten.

This week’s webinar title is “Who is afraid of the bad, big lateral chest”. The webinar will take place on Wednesday, September 30 at 12:00 CEST. You can register here.

The initial case is a PA chest radiograph of a 61-year-old man with hemoptysis.

Do you see any abnormality?
1. Yes
2. No
3. I want a lateral chest

Register for the webinar and lear more about this case and others!

Click here to see the answer

Findings: PA radiograph (A) does not show any significant findings. The lateral view shows a posterior pulmonary nodule with irregular contour (B, arrow). A typical donut sign is visible (B, circle), indicative of enlarged subcarinal lymph nodes.

Enhanced axial CT and PET-CT show confirm the pulmonary nodule (C-D, arrows) and the subcarinal lymphadenopathies (C-D, red arrows).

Final diagnosis:

Carcinoma hidden in the PA view behind the right hilum with metastases to subcarinal lymph nodes.
 
Congratulations to drpeca who was the first to want a lateral view.
 
Teaching point: remember that about 26% of the lung is hidden in the PA view. A lateral chest radiograph is indispensable to study the chest.

Emergency #24 – Flashcard

A 43-year-old man with inflammation and lower abdominal pain:

What do you see?

Click here to see the answer

* Inflammatory wall thickening of the sigmoid colon.
* Multiple diverticula, but one enlarged with thickened enhancing wall (arrow).
* Surrounding haziness of the mesosigmoid fat.
* Peritoneal accentuation

Typical image of diverticulitis, in a typical location with typical presentation

Teaching point

Look for signs of perforation or abscess formation