Cáceres’ Corner Case 242 – SOLVED

Dear friends, welcome back!

Today I am showing a straightforward case to ease you into the new season. Promise I will not mention Covid-19 at all.

Today’s case is a pre op PA radiograph for knee surgery in a 47-year-old woman.

What do you see?

Come back on Friday to see the answer!

Click here to see the answer

Lung and mediastinum do not show any relevant findings. An isolated air-fluid level is visible in the left upper quadrant of the abdomen (A, arrow). The inner border of the cavity is smooth. The gastric bubble is visible under the left hemidiaphragm (A, red arrow).

Given that the patient is asymptomatic, an abdominal abscess or bowel obstruction/ volvulus can be safely excluded. A large intestinal diverticulum could be a possibility. I suspected a more mundane diagnosis: a review of the clinical history discovered that an intragastric balloon had been inserted fourteen months earlier.

Final diagnosis: air-fluid level in an intragastric balloon for morbid obesity
Congratulations to all of you who detected the air-fluid level. Kudos to Flemming Ghomsen who came close to the diagnosis.

Intragastric balloons for bariatric surgery may be filled with air or with saline. In the second case they may present an air-fluid level due to room air mixing during the injection of fluid.

Teaching points:

1. Remember to look under the diaphragm. You may discover interesting findings.
2. In your differential diagnosis always include iatrogenesis as a possible cause.

Cáceres Corner Case 233 – Vignette

Dear Friends,

Recommendations for this week: A history of the world in 100 objects written by Neil McGregor, Director of the British Museum. Series: Good omens (Amazon). 

Today’s radiographs belong to a 51-year-old man with moderate cough.
Do you see any abnormality?
If so, where?

1.  Upper third
2. Middle third
3. Lower third
4. Don’t see it

Click here to see the answer

Findings: PA radiograph shows a left parahilar opacity (A, arrow), seen as an anterior elongated opacity in the lateral view (B, arrow). Its shape in the lateral view suggests mucous impaction.

Click here to see more images

Enhanced CT was done. What would be your diagnosis?

1. Benign endobronchial tumor
2. Allergic aspergillosis
3. Foreign body
4. None of the above

Click here to see the answer

Findings: enhanced axial CT shows an endobronchial obstruction with a distal mucous impaction (C, arrow), also visible in the coronal reconstruction (D, arrow). The clue to the diagnosis lies in recognizing two small lung nodules in the axial view ( C, red arrows) and another one in the right lung in the coronal view (D, red arrow). In addition, there is an enhancing nodule in the gallbladder (D, yellow arrow). These findings suggest widespread malignancy and the correct answer should be 4. None of the above.

Click here to see more images

Bronchoscopy discovered a dark tumor in the lingular bronchus (E), as well as numerous small implants in the trachea, also visible in the CT (F, arrow).
Review of the clinical history discovered that the patient had been operated on for melanoma of the back four years earlier.

Final diagnosis: widespread metastases from melanoma, one of them causing bronchial mucous impaction

Mucous impactions may be multiple or localized. Multiple impactions are related to respiratory diseases that cause bronchiectasis and thick mucus (allergic aspergillosis, cystic fibrosis) whereas localized ones are secondary to segmental endobronchial lesions.

The prevalence of bronchogenic carcinoma makes it the most common cause of localized mucus impaction in clinical practice. Other malignant tumoral lesions are metastases and carcinoids.

Endobronchial metastases represent about 2% of lung metastases. They are usually accompanied by metastatic nodules. They may occur in association with any tumor, but the most common sources are colon, breast, kidney and melanoma.

Cáceres Corner Case 230 – Vignette

Dear friends,

Today’s radiographs belong to a 27-year-old with dyspnea.


1. Giant bulla
2. Emphysema
3. Loculated pneumothorax
4. Any of the above

Click here to see the answer

Findings: PA radiograph shows overinflation of the lower right lung pushing the minor fissure upward (A, arrow), simulating partial RUL collapse. In the lateral view there is a circular line (B, red arrows) suggesting the wall of a giant bulla. The correct diagnosis is made by detecting overinflation of the left lower lung and scarce vascularity, an indication that we are not dealing with localized disease of RLL (giant bulla or pneumothorax) but with disease of both lower lobes. Therefore the correct diagnosis should be 3. Emphysema.

Another finding in favor of emphysema of lower lobes is redistribution of the pulmonary circulation in which the diameter of the vessels of upper lobes (B) is larger than those of the lower lobes (C).
Pulmonary vascular redistribution is usually due to cardiac failure but it may also occur in emphysema of lower lobes in which vascular flow is redirected to the functioning upper lobes.

Click here to see more images

Unenhanced axial CT confirm the relative sparing of upper lobes (D) and the severe emphysematous changes of lower lobes (E).

Coronal CT (F) shows severe emphysema of lower lobes and increased vascularity of upper lobes as well as discrete bronchial dilatations. Sagittal reconstruction demonstrates that the apparent wall of a bulla seen in the lateral chest radiograph represents the minor and major fissures (G, arrows) limiting a markedly emphysematous right middle lobe.

Diagnosis: Pulmonary emphysema secondary to alpha 1 antitrypsin deficiency.

This condition affects young persons and causes severe emphysema of lower lobes and bronchial dilatations.

I am showing this case because is a good example of satisfaction of search (missing changes of the left lower lobe will lead you to the wrong diagnosis).
It is also a nice example of vascular redistribution secondary to pulmonary disease.

Cáceres’ Corner Case 215 – SOLVED

Dear Friends,

Today’s case has been provided by my good friend and former resident Victor Pineda. Radiographs belong to a 56-year-old man with cough and fever.
What do you see?

More images will be shown on Wednesday!

Click here to see the images shown on Monday

Dear friends hope these new images help you with the diagnosis.

Click here to see more images

Click here to see the answer

Findings: PA chest radiograph shows a large paramediastinal lung opacity (A, arrow) that at first glance suggest malignancy. The clue to the diagnosis lies in identifying multiple bronchiectasis in the right and left central lung fields (A, circles).

The lateral view confirms the opacity in the posterior segment of the RUL (B, arrow) and bronchiectasis in the anterior clear space (B, circle).

Central bronchiectasis accompanied by lung opacities are typical of diseases with thick tenacious mucus and are the hallmark of cystic fibrosis o allergic bronchopulmonary aspergillosis. Coronal and axial CT confirm the presence of numerous central bronchiectasis, one of them with a large mucous impaction (C and D, arrows).

In the mediastinal window the impacted mucus is increased in density (E and F, arrows), which is a pathognomonic sign of ABPA.

Final diagnosis: ABPA with central bronchiectasis and dense pulmonary impaction
Congratulations to MG who was the first to answer and made a valiant effort to diagnose a difficult case.
Teaching point: this case looks difficult, but the diagnosis is easy if we identify basic findings. Discovering central bronchiectasis narrows the diagnosis to two entities and CT confirms one of them.

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.

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 142 – Art of interpretation – SOLVED

Dear Friends,

today I am presenting another “Art of interpretation” case. I like them and think they have good teaching value.
Radiographs were taken for preoperative knee surgery in a 21-year-old man.

What is the most likely diagnosis?

1. Swyer-James-McLeod syndrome
2. Congenital hypoplasia of left lung
3. LUL collapse
4. None of the above

Click here to see the images

Click here to see the answer

Findings: PA radiograph shows a hyperlucent left lung with a small elevated hilum (A, white arrow). The trachea is deviated towards the left and the left main bronchus is curved upward (A, blue arrow). There is a small peak in the left hemidiaphragm (A, red arrow). And there is a triangular-shaped paraspinal opacity (A, circle), better seen in the cone down view (B, white arrow), with two linear metallic opacities inside (B, red arrows).

The lateral view (C) is unremarkable. Although the PA findings suggest loss of volume of the LUL, there are some negative findings: no anterior displacement of the left major fissure and no opacity indicative of LUL collapse.

Analysis of the findings

There are four obvious findings:

1. Hyperlucent left lung with small left hilum
2. Tracheal deviation to the left
3. Upward curving of left main bronchus
4. Juxtaphrenic peak (*)

All these findings are indicative of LUL volume loss with compensatory overinflation of the LLL.

There are two less obvious findings, which are diagnostic:

Paramediastinal opacity with surgical staples
No signs of LUL collapse in the lateral view

The first indicates previous surgery and the second excludes LUL collapse. Taken together, these findings lead to the obvious conclusion that the patient had undergone a previous lobectomy.

(*) The juxtaphrenic peak sign was described by my late friend Kenneth Kattan as an indirect sign of LUL collapse. Semin Roentgenol 1980; 15:187-193


In the past, the patient had embryonal carcinoma of the testicle with a metastatic nodule in the LUL (A and B, arrows). He had undergone LUL lobectomy by video-assisted thoracic surgery one year before.

Final diagnosis: LUL lobectomy for metastasis of embryonal testicular carcinoma

I’m showing this case to emphasize the importance of identifying metal sutures in the chest radiograph. Nowadays, most surgical procedures are done by video thoracoscopy which doesn’t leave any telltale signs other than surgical staples. These are difficult to see because of their small size and because high kV “burns” metal density.

Staples are visible as a faint longitudinal ring chain somewhat denser than the surrounding tissues. It’s very important to be familiar with their radiographic appearance because they offer valuable information about previous surgery.
When staples are detected, our interpretation of associated findings may change, as occurred with the case presented.

To familiarize you with the radiological appearance of surgical staples, I’m showing three more cases.


88-year-o.ld man with dementia and moderate dyspnea. Chest radiographs show a nodule in the RUL (A and B, arrows). PA view shows post-surgical changes at the left 6th and 7th ribs and a hyperlucent left lung with a small hilum. There are surgical clips in the mediastinum (A and B, red circles). These findings suggest a previous LUL lobectomy and a second primary tumor. The patient’s records disclosed a LUL lobectomy for carcinoma twenty years earlier. The second primary tumor was confirmed by needle biopsy.
The radiographic findings are typical of “old” chest surgery.


PA radiograph of a 23-year-old woman with a nondescript LUL infiltrate (A, arrow). Close-up view reveals a longitudinal ring chain of staples within the infiltrate (B, arrows), pointing to a man-made opacity secondary to video thoracic surgery.

Diagnosis: changes after endoscopic LUL bullectomy for recurrent pneumothorax.

I saw this case three weeks ago and it is still unproven. A 44-year-old woman from another country came for a routine cardiac checkup. The PA chest radiograph shows a serpiginous opacity in the LLL (A, arrow) with a ring chain of staples in the periphery, better seen in the cone down view (B, arrows). On questioning, the patient mentioned previous endoscopic surgery for a nodule in the left lung two years ago. Enhanced CT shows a solid lesion with staples in the periphery (C, arrow).

As the patient could not provide previous medical records, we were unable to ensure that the changes were attributable to scar tissue. A follow-up CT has been scheduled.

Final words: Staples are difficult to reproduce on the computer screen, and I have done my best. I assure you that they are easily visible on a 14 by 17 reading console, provided that you see and recognize them 🙂

Follow Dr. Pepe’s teaching points:

1. Surgical staples are visible as a faint longitudinal ring chain.

2. They indicate previous surgery and help to interpret the chest findings under a new light.

Cáceres’ Corner Case 205

Dear Friends,

Today I am showing preoperative radiographs for hand surgery in a 53-year-old man.

What do you see?

More images will be shown on Wednesday.

Click here to see the images

Dear Friends,

showing today chest radiographs taken one year earlier.

Do they help?

Click here to see the new images

Click here to see the solution

Findings: PA chest radiograph shows an ill-defined opacity in the left middle lung field (A, arrows). It is located in the anterior clear space in the lateral view and has a stippled appearance (B, arrows). In addition, there is a flat irregularity in the dome of the left hemidiaphragm in the PA view which appears to be calcified (A, red arrow).

Previous radiographs one year earlier show the same findings, unchanged (C-D, arrows).

The clue to the diagnosis lies in the irregularity of the dome of the left hemidiaphragm, that looks like a calcified plaque. This finding suggests that the apparent pulmonary opacity in the PA view may be a pleural plaque see “on face”. It is not seen as a line in the lateral view because the curvature of the anterior thoracic wall does not offer a straight interface to the X-ray beam.

CT confirms calcified anterior pleural plaques in both hemithoraces (E-F, arrows).

Coronal and sagittal CT confirm the calcified plaque in the diaphragmatic dome (G-H, red arrows).

The patient was found to have a history of asbestos exposure.
Final diagnosis: Asbestos-related pleural disease simulating pulmonary infiltrate.

Congratulations to S, who was the first to make the diagnosis. Silver medal to VL.
Teaching point: remember the deceitful appearance of pleural plaques shown in Diploma case 140. Some of you were fooled by it!

Dr. Pepe’s Diploma Casebook: CASE 141 – SOLVED

Dear Friends,

Today I am showing radiographs of a 47-year-old woman with chronic cough.
What do you see?

Leave your comments here and come back on Friday to see the answer.

Click here to see the images

Click here to see the answer

Findings: PA radiograph shows marked downward displacement of the right hilum (A, white arrow) and verticalization of the intermediate bronchus (A, red arrow). These findings are indicative of marked volume loss of RLL. The lateral view (B) is unremarkable.

Enhanced coronal CT confirms the descended right hilum (C, white arrow), as well as the vertical intermediate bronchus (C, red arrow). A different slice shows a small calcified triangular shadow (D, arrow), which represents a markedly collapsed RLL.

Final diagnosis: severe RLL collapse due to previous TB

In the previous webinar (Diploma case 139), I described the common signs that suggest lobar collapse. In this presentation I want to review atypical forms of lobar collapse and how to recognize them.
The main signs of lobar collapse are volume loss and increased opacity of the lobe. Atypical presentations lack these traits, and the lobe appears to have an increased volume (drowned lobe) or to have collapsed without increased opacity (aerated collapse). A third variant would be a lobe that has lost most of its volume (extreme collapse) and therefore is difficult to identify as such, as occurred in the initial case.

In extreme collapse, the affected lobe is severely decreased in size and may be overlooked, or confused with a different process (Fig. 1). The diagnosis is suggested by secondary findings, such as hilar displacement and/or increased lucency of the unaffected lobe(s) (Figs. 2 and 3).

Fig. 1. 57-year-old man with carcinoma of the RUL bronchus causing severe RUL collapse. The medial displacement of the collapsed lobe simulates mediastinal widening (A, white arrow). The clue to the diagnosis is a small and slightly elevated right hilum (A, red arrow). The lateral view (B) is unremarkable.

Enhanced axial CT image depicts a horizontal sliver of tissue, corresponding to the markedly collapsed RUL, sharply outlined by the minor fissure (C and D, white arrows). Note the obstructed RUL bronchus (D, red arrow). Bronchogenic carcinoma.

Fig. 2. Pre-op film for cataracts in a 72-year-old man. PA chest film shows a lucent left lung. Severe LLL collapse is suspected because of the downward left hilar displacement (A, white arrow) and a triangular-shaped paramediastinal opacity (red arrow). The posterior left hemidiaphragm is blurred in the lateral view (B, arrow).

Enhanced axial CT shows the markedly collapsed lobe (C, arrow). Coronal CT depicts a mass obstructing the LLL bronchus (D, arrow). Final diagnosis: carcinoma.

Fig. 3. 67-year-old woman with extreme LUL collapse secondary to previous TB. The diagnosis is suspected because the collapsed lobe causes haziness of the left mediastinal border in the PA film (A, arrows). The expanded LLL causes increased lucency of the left hemithorax. Lateral view shows marked anterior displacement of the left major fissure (B, arrows).

Coronal and sagittal CT confirm the extreme LUL collapse with bronchiectasis. The major fissure is well depicted in the coronal and sagittal reconstructions (C and D, arrows).

The finding known as drowned lobe is a variant of lobar collapse in which the lobe does not decrease in size but instead, enlarges. It occurs when a slow-growing proximal tumor permits accumulation of distal secretions and infection, causing an increase in size of the lobe (Fig. 4). Bulky tumor masses may contribute to this enlargement (Fig. 5).

Fig. 4. 55-year-old woman with widespread lung disease and a large opacity occupying the upper two thirds of the right lung in the PA radiograph (A, white arrows). The right hilum (A, red arrow) is in a normal position. The lateral view shows that the opacity corresponds to an enlarged RUL (B, arrows).

Enhanced axial and coronal CT shows the enlarged RUL lobe (C and D, white arrows), secondary to central obstruction of the RUL bronchus (C and D, red arrows). Diagnosis: drowned RUL secondary to central carcinoma

Fig. 5. 47-year-old woman with drowned LLL, which appears in the PA radiograph as a uniform mass occupying the lower two thirds of the left lung (A, arrow), recognizable in the lateral view as a swollen LLL (B, arrows).

Enhanced axial CT confirms the swollen LLL (C, white arrow). PET-CT shows that part of the bulk is due to a large tumor mass (D, white arrow), invading the pulmonary veins and left atrium (C and D, red arrows).

In aerated collapse the lobe loses volume, but does not increase in opacity, making the collapse less obvious. This happens because increased opacity is not related with volume loss, but rather with the amount of secretions within the lobe. If the partially collapsed lobe contains air, the lobe will appear to have normal lucency.
In aerated collapse, the diagnosis is suspected by displacement of the hilum, the fissure, or both (Figs. 6-8).

Fig. 6. Aerated RLL collapse in carcinoma. PA chest film depicts a right hilar mass (A and B, red arrows), with a descended hilum. The lowered major fissure is barely visible (A, white arrow). In the lateral view, the collapsed lobe is seen as a faint opacity projected over the spine (B, white arrow). Bronchoscopy confirmed an endobronchial carcinoma.

Fig. 7. Aerated RLL collapse secondary to bronchiectasis. PA radiograph shows a markedly displaced major fissure simulating an inferior accessory fissure (A, white arrow). There is marked downward displacement of the right hilum (A, red arrow). Coronal CT confirms the findings (B, red and white arrow), with bronchiectasis and an open RLL bronchus

Fig. 8. 75-year-old man who had TB in his youth. Chest radiographs show aerated collapse of the LUL, demonstrated in the PA view by the small elevated left hilum (A, arrow) and by the anterior displacement of the major fissure in the lateral view (B, arrows). Note that the LUL is well aerated.

Follow Dr. Pepe’s advice:

1. Common manifestations of lobar collapse are loss of volume and increased opacity.

2. Uncommon manifestations of lobar collapse are extreme collapse, drowned lobe, and aerated collapse.

3. These uncommon manifestations are suspected based on secondary signs: hilar and/or fissure displacement and increased lucency of the unaffected lobe(s).

Cáceres’ Corner Case 203 – SOLVED!

Dear Friends,

Today I am showing radiographs of a 40-year-old man with chest pain.
What do you see?

More images will be shown on Wednesday.

Click here to see the images

Dear Friends,

showing today enhanced CT images of the case.

Do they help?

Click here to see the images

Click here to see the answer

Findings: PA radiograph shows a mediastinal mass (A, arrow) superimposed to the right hilum. In the lateral view the mass is faintly visible behind the distal trachea (B, circle). This location excludes a right hilar mass, because the right hilum is anterior to the trachea.

Enhanced coronal and sagittal CT confirm a posterior mediastinal mass (C-D, arrows) with necrotic areas and marked contrast enhancement. This is an important finding because it limits the differential diagnosis to four conditions: intrathoracic goiter, Castleman’s disease, paraganglioma and hemangioma.
Some of you have mentioned extramedullary hematopoiesis. In my (limited) experience I don’t recall seeing avid contrast enhancement in it. I have asked some friends and searched the web without finding a clear answer. If any of you have better information I am willing to be corrected. At any rate, this patient does not have any bone abnormalities, which makes the diagnosis of extrapulmonary hematopoiesis very unlikely.
Final diagnosis: posterior mediastinal paraganglioma surgically proved. A similar case was presented in case 168 of Caceres’ corner.
Congratulations to MK, who was the first to suggest the correct diagnosis.
Teaching point: remember the four mediastinal processes with avid contrast enhancement: intrathoracic goiter (frequent), Castleman´s disease and paraganglioma (uncommon) and hemangioma (never saw a case).