Dr. Pepe’s Diploma Casebook 158 – SOLVED

Dear Friends,

this is the last case of the first semester. Will meet again in September.
Wish all of you a very happy summer vacation!

This is a new “art of interpretation” case. Radiographs belong to a 40-year-old woman with mild cough.

What do you see?


1. Chronic TB changes
2. AV malformation
3. Bronchial atresia
4. Any of the above

Click here to see the answer

To refresh your memory, remember that interpreting a chest radiograph involves three basic steps:

1. Gather information. Examine the radiographs carefully and collect all the pertinent information. Remember that overlooking visible findings is the main cause of errors.

2. Analyze the findings. Once collected, the findings should be properly evaluated, and an opinion should be offered.

3. Decide on the next step to reach the diagnosis.

Step 1. Information:

In this patient the lateral view is unremarkable.
All relevant findings are seen in the PA radiograph:

1. Tubular branching opacities in the left upper lung (A, red arrows)
2. Increased lucency of left upper lung (A, circle)
3. Negative finding: the left hilum is in its normal position.

Step 2. Analysis of the findings:

1. Branching tubular opacities have a limited differential diagnosis: either they are pulmonary vessels or mucous-filled dilated bronchi.

2. Hyperlucent lung is a reliable sign of lung disease when complemented with an expiration film to demonstrate air-trapping.

3. The normal position of the left hilum is a negative finding that excludes a fibrotic process in the LUL (I.e. chronic TB), which should cause upper retraction of the hilum.

The combination of a lucent lung lesion with branching tubular opacities points towards an obstructive process of a segmental bronchus with mucous impaction (Obstruction of a lobar bronchus would cause lobar collapse instead of increased lucency).


Step 3. Decide on the next step

Once segmental bronchial obstruction is suspected in the chest radiograph, the best procedure to confirm it is an enhanced chest CT with expiratory views. In this case it shows attenuated upper lobe vessels (B, arrows) and obvious mucous impactions (B-C, red arrows).
Axial CT with lung window confirms the increased lucency of the apical-posterior segment of the RUL (D, circle)

Inspiration/expiration axial CT views (E-F) confirm segmental air trapping on the left.

Bronchoscopy did not show any inflammatory or tumoral changes in the LUL bronchus. The orifice of the apical-posterior segment was missing.

Final diagnosis: bronchial atresia of apical-posterior segment of LUL

In my experience, bronchial atresia is the most common congenital lung malformation seen in adults. Congenital bronchial atresia results from proximal interruption of a segmental bronchus, which causes overinflation of the affected segment and secondary mucus impaction. Chest radiography shows a focal hyperlucent area with internal mucus impaction. CT depicts these findings to better advantage. Inspiration and expiration views help to confirm air-trapping. In case of doubt, bronchoscopy excludes other causes of bronchial obstruction.

Congenital bronchial atresia may present different appearances, as shown in the following case of one of our X-ray technicians.

30-year-old female, asymptomatic. PA chest radiograph (A) shows hyperlucent left lung with discrete dextroposition of the heart. Expiration film (B) shows air-trapping on the left with deviation of the mediastinum towards the right. Note a thick tubular shadow in the left lower lung (A-B, red arrows), compatible with bronchial impaction. The findings are suggestive of congenital bronchial atresia

Axial and coronal enhanced CT show increased lucency of the posterior segments of LLL with a central mucous impaction (C-D, red arrows)

Decreased vascularity of LLL and central mucous impaction (E-F, red arrows) are better demonstrated in the MIP reconstruction.

Coronal view eleven years later show that air is now present within the dilated bronchus, confirming the diagnosis (G-H, circles) .

Dr. Pepe’s teaching point:

Hyperlucent lung with mucous impaction are the hallmark of congenital bronchial atresia.

Cáceres’ Corner Case 241 – SOLVED

Dear Friends,

Today’s radiographs belong to a 24-year-old woman with cough and fever. What do you see?

More images will be shown next Wednesday and the answer will be published on Friday.

Click here to see Monday images

Dear Friends,

Showing today CT images of the chest. What do you think?

Click here to see the new images

Click here to see the answer

Findings: Chest radiographs show air-space disease in the right lower lobe (A-B, arrows). There is marked widening of the right paratracheal line (A, red arrow) suggestive of mediastinal lymphadenopathy.

Axial CT with lung window shows RLL air-space disease without cavitation (C, arrow). Mediastinal window at different levels confirms enlarged paratracheal, subcarinal and neck lymph nodes with hypodense center (D-F, red arrows). These findings should suggest active tuberculosis as the first possibility.
Although TB usually affects upper lobes, isolated involvement of lower lobes occurs in about 7% of cases.
Mycobacterium tuberculosis was found in the sputum.

Final diagnosis: active TB.
Congratulations to Archanareddyt who was the first to make the diagnosis.
 Teaching point: lymph nodes with hypodense center may occur in several processes (treated tumors, Whipple’s, etc.), but in the appropriate clinical situation, the first diagnostic consideration should be tuberculosis.

Dr. Pepe’s Diploma Casebook 157 – SOLVED

Dear Friends,

The leading case of this week’s Diploma has been provided by my good friend Jordi Andreu. Radiographs belong to an asymptomatic 48-year-old woman.


1. Neurogenic tumor
2. Pulmonary hamartoma
3. Pleural fibrous tumor
4. None of the above

What do you think? Come back on Friday to see the answer!

Click here to see the answer

Findings: PA chest radiograph shows a rounded opacity in the left apex (A, arrow). All diagnosis are possible, as the pulmonary apex is a narrow space and it is very difficult to determine the origin of a mass. The clue lies in the nodular opacities in the neck (A, circle) which raise the possibility of superimposed hair braid.
Unenhanced coronal CT (B) does not show any mass, confirming that the finding is artifactual.

Final diagnosis: superimposed hair braid simulating pulmonary disease

The purpose of this presentation is to discuss elements in or about the soft tissues of the chest wall that may simulate lung disease. Those related to the thoracic skeleton were shown in Diploma case # 57.
This Diploma complements the non-significant findings described in webinar eight.

I have classified them into three groups, the first one related to the soft tissues of the chest wall while the other two are external to the body:

1. Nipples and skin lesions
2. Hair and/or hair implements
3. Garments

Nipple Shadows

Nipple shadows are seen in 3% to 10% of PA chest radiographs. In about 10% of these patients, the identification may raise doubts. Comparison with previous films will confirm the stability of the nodules (Fig. 1). In case of doubt, nipple markers should be placed. Routine use of nipple markers has been proposed in oncologic patients.

Fig. 1. 58-year-old man with typical bilateral nipple shadows (A, arrows), unchanged in comparison with a previous film (B, arrows). Nipples are well seen on axial CT in the same patient (C, arrows). Nowadays, patients may come with their own nipple markers! (D).

Unilateral enlarged nipple shadows are suspicious findings. Visual inspection should be done to confirm that the nipple is indeed enlarged (Fig. 2). Occasionally, a true lung nodule may simulate a nipple shadow, even with nipple markers. In such cases, CT will correct our error (Figs. 3-4)

Fig 2. 61-year-old woman with left pleuritic chest pain. PA chest film shows a small amount of left pleural fluid (A, white arrow) and a nodule at the right costophrenic angle (A, red arrow). Visual inspection showed a large right nipple as the cause of the false nodule. Two weeks later, the pleural effusion has disappeared, and the nipple shadow is no longer seen (B).

Fig. 3. 54-year-old man with a renal tumor. PA film shows a nodule in the LLL (A, arrow) that simulates a nipple, even with a nipple marker (B, arrow). Axial CT shows a metastatic nodule in the LLL and a larger one in the RLL, not seen in the PA chest radiograph (insert, arrows).

Skin lesions

Skin lesions may also cause false lung nodules. Visual inspection of the chest will demonstrate them and confirm the diagnosis (Fig. 5). If there is any doubt, a marker can be used.

Fig. 5. Chest wart simulating a lung nodule in the PA film (A, arrow). Lateral film shows the wart in the skin of the anterior chest wall (B, arrow). The wart is higher in this view because the upheld arms elevate it.

Occasionally, a discrepancy in density between both breasts, usually related to previous surgery, may simulate pulmonary pathology (Fig 6).

Fig 6. 65-year-old woman with syncope. PA radiograph shows a rounded opacity in the right lung (A, arrow), suspected to be a pulmonary infiltrate. Axial CT (B) show normal lungs. The opacity is due to a superimposed right breast prosthesis (B-C, arrows).


In my experience, hair is a common cause of opacities in the lung apices (Fig 7).
Strands of loose hair may project over the upper lung, simulating linear fibrotic infiltrates (Fig 8). Rubber bands at the end of braids may be confused with pulmonary nodules (Fig. 9). A long braid may fool us and consider it intrapulmonary disease (Fig 10).

In most cases, the clue to the diagnosis lies in recognizing that the abnormality extends to the neck.

Fig. 7. Braid simulating an apical pulmonary nodule (A-B, arrows). The rubber band (A-B, red arrows) suggests the correct diagnosis

Fig. 8. Loose hair simulating a linear infiltrate or fibrosis in the right apex (A, white arrow). Note the same appearance in the lower neck (A, red arrow). The apex looks normal after the hair is lifted (B). The opaque rounded opacity that looks like a hair clasp (A-B yellow arrow) is a cervical disk prosthesis.

Fig 9. Two patients with rubber bands at the end of a braid simulating pulmonary nodules (A-B, arrows). In both, the braids are visible in the neck (A-B, red arrows). Despite that, patient B was referred for a CT examination to evaluate a left lung nodule.

Fig. 10. 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.

Clothing artifacts

Clothing artifacts occur when the technician does not ask patients to remove garments that have logos or images on them. This usually happens with women, out of respect for modesty (Figs. 11 and 12).

Fig. 11. 27-year-old woman with multiple miliary nodules in both lungs (A, circles). The opacities result from a jeweled panther on the shirt she was wearing (B).

Fig 12. 45-year-old woman with previous breast carcinoma. PA radiograph shows small nodules in lower lungs (A, circles). Lateral view proves that the nodules are in a blouse (B, arrow)

Other types of body artifacts may cause dubious opacities in the chest radiograph (Figs 13 and 14)

Fig 13. 29-year-old man with a barely visible non-displaced fracture of the left clavicle (A, arrow), well demonstrated in the 3-D CT reconstruction (B). Components of the support brace for the fracture simulate enlarged upper lobe vessels (A, red arrows).

To end the presentation, in the last two months we have been acquainted with a new artifact: the wire in the face masks (Fig 14)

Fig 14. Routine chest radiograph during the Covid-19 scare. Notice the wire in the face mask (A-B, arrows)

Follow Dr. Pepe’s advice:

1. Unilateral nipple shadows may generate diagnostic problems.
2. If a hair artifact is suspected, look at the soft tissues of the neck.
3. Garments may create weird lung shadows.

Cáceres’ Corner Case 240 – SOLVED

Dear Friends,

Today’s case has been provided by my good friend Victor Pineda. Radiographs belong to a 36-year-old man with cough and fever. For comparison, I am including radiographs taken nine years earlier.


1. Chronic TB changes
2. Endobronchial lesion
3. Congenital lesion
4. None of the above

What do you see? More images will be shown on Wednesday. Come back on Friday to see the answer.

Click here to see the images posted on Monday

Showing coronal and axial CT images. What do you think?

Click here to see the CT images

Click here to see the answer

Findings: Pa radiograph shows a left ill-defined opacity that blurs the upper mediastinal contour (A, arrow) and the lower cardiac border (A, red arrow). In the lateral view there is a retro-sternal line that goes from top to bottom (B, arrows). The appearance is typical of marked LUL collapse, which has not changed in the last nine years. Therefore, the most likely diagnosis is a benign condition that occludes the origin of the LUL bronchus.

Enhanced axial and coronal CTs show marked irregularity of the origin of the LUL bronchus (C, arrow) due to a large mass with coarse calcification (C-D, circles) causing distal lobar collapse. The most likely diagnosis is a benign tumor, either carcinoid or hamartoma. Given the size of the mass and the higher frequency of carcinoid, I would favor this diagnosis. It was proved by biopsy and surgery.

Final diagnosis: endobronchial carcinoid with LUL collapse

Congratulations to Ahmed Al Ani who was the first to suggest the correct diagnosis in the plain film.
Teaching point: Detecting LUL collapse in chest radiographs is important because the great majority are secondary to bronchogenic carcinoma. This patient was lucky.

Cáceres’ Corner Case 239 – SOLVED

Dear Friends,

Today’s case has been provided by my good friend Alberto Villanueva. PA radiograph of a 55-year-old male, taken during a workup for rectal carcinoma.


1. Metastasis
2. Pericardial cyst
3. Carcinoma of the lung
4. None of the above

More images will be shown next Wednesday. What do you see?

Click here to see images shown on Monday

Dear Friends,

in my opinion it is difficult to determine in the plain film the origin of large masses adjacent to the mediastinum. I am showing today coronal and axial enhanced CTs.

What do you think?

Click here to see more images

Click here to see the answer

Findings: PA radiograph shows a rounded well-defined mass at the costophrenic angle in the lower left hemithorax (A, arrow). We can infer that the mass is anterior because is displacing the heart towards the right and it does not obliterate the para-aortic line.
In my opinion, when a large mass if adjacent to the midline it is difficult to determine whether it is mediastinal or pulmonary.

Coronal and axial enhanced CT show a solid mediastinal mass with areas of necrosis (B-C, arrows). The most common solid lesion in the cardiophrenic angle are enlarged lymph nodes, which usually are multiple and not very large. In big soft-tissue tumors of this area a thymic origin should be suspected. Although thymic tumors originate in the anterior superior mediastinum, they may slide down along the mediastinal planes and appear at the cardiophrenic angle in the lower mediastinum. Biopsy confirmed the diagnosis of thymoma.

Final diagnosis: mediastinal thymoma

Congratulations to Mohamed Abdulghaffarand MK who were the first to suggest the correct diagnosis

Teaching point: Remember that CT is very helpful in diagnosing cardiophrenic angle masses according to their radiographic density: fat (pericardial fat pad, Morgagni’s hernia); fluid (pericardial cyst) and soft-tissue ( lymphadenopahy and the occasional thymic tumour).

Cáceres Corner Case – Vignette 238

Dear Friends,

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


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 – Vignette 237

Dear Friends,

If you are Sci-Fi fans I recommend this week the novel “The windup girl” and the short stories collection “Pump six” by Paolo Bacigalupi.

Today’s radiographs belong to a 57-year-old woman with cough and fever. She had an osteosarcoma of the lower limb removed eight years earlier.


1. Carcinoma
2. Pneumonia
3. Tuberculosis
4. Any of the above

Click here to see the answer

Findings: PA chest shows haziness of left hemithorax, elevation of the left hilum (A, arrow) and luftsichel (A, red arrow), typical signs of LUL collapse. The collapse is confirmed by the marked displacement of the major fissure on the lateral view (B, arrows). At this point, the best diagnosis is an endobronchial lesion, most likely carcinoma

Click here to see more images

CT with and without contrast enhancement was done. What would be your diagnosis?

1. Carcinoid
2. Carcinoma
3. Endobronchial TB
4. Endobronchial metastasis

Click here to see the answer

Findings: unenhanced CT demonstrates LUL collapse with coarse calcification that seems to follow the path of the bronchus (C, arrows). Enhanced CT shows a non-enhancing endobronchial lesion at the origin of the LUL (D, arrow).

Of the diagnosis offered, the coarse calcification makes carcinoma very unlikely and suggests a carcinoid tumor, although I would expect some enhancement after contrast injection. Given the previous history of osteogenic sarcoma, endobronchial metastases should be considered. I would vote against TB.

Bronchoscopy found a mass occluding the LUL bronchus. Biopsy returned the diagnosis of osteosarcoma.

Final diagnosis: endobronchial metastases from osteogenic sarcoma.

I am showing this unusual case because it is my first and probably my last case of endobronchial metastasis from osteogenic sarcoma. It is also unusual the prolonged span of time (eight years) between the removal of the primary and the appearance of the metastasis.
Remember that the most common cause of LUL collapse is first and foremost a carcinoma of the lung. Endobronchial metastases can give a similar appearance and are more common in tumors of breast, kidney and melanoma although they may occur in any type of tumor, as in the present case.

Dr. Pepe’s Diploma Casebook 155 – SOLVED!

Dear Friends,

Today I am presenting the leading case of a new webinar entitled: “Sherlock Holmes and the curious finding in the chest radiograph”.

AP radiograph belongs to a newborn with respiratory distress.


1. Diaphragmatic hernia
2. Lung tumor
3. Pneumonia
4. None of the above

What do you see? Come back on Wednesday to see the answer and the webinar!

Click here to see the answer

Findings: at a first glance, the predominant abnormality is a large bump in the left hemidiaphragm (A, arrow), suggestive of localized eventration or hernia. However, there is and additional important finding: both humeri are not visible (A, circles).
This baby was born with a congenital absence of the arms (amelia).

I am showing this case to stress the importance of discovering so-called negative findings. Our training emphasizes the discovery of positive findings and forgets teaching us to detect structures that are absent, as this case proves.
My apologies for tricking you, but I was trying to prove my point. You can get more information about negative findings in today´s webinar.

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.