Dr. Pepe’s Diploma Casebook – All you need to know to interpret a chest radiograph – First Session – CASE 147 – SOLVED

There are some things which cannot be learned quickly, and time, which is all we have, must be paid heavily for their acquiring. They are the simplest things; and, because it takes a man’s life to know them, the little new that each man gets from life is very costly and the only heritage he has to leave

Dear friends, this quote from Ernest Hemingway serves as introduction to the next series of webinars. From October to March I intend to give a webinar every two weeks describing my basic approach to interpreting the chest radiograph. The subject is ample, and will continue with a second series in 2021.

To start, I am showing a preoperative PA chest radiograph for varices in a 60-year-old woman. The chest was read as normal, but there is an abnormality, difficult to detect.
Do you see it?

The answer was given during a webinar. You can watch the webinar here

Click here to see the answer

Findings: PA radiograph shows a small nodule overlapping the left cardiac border (A-B, arrows). The nodule was overlooked, and the chest was read as normal.

A chest radiograph taken four years later shows a marked increase in size of the nodule (C, arrow). Enhanced axial CT shows a non-enhancing low-density nodule (-30 H.U.)
(D, arrow). Needle biopsy confirmed the diagnosis of hamartoma.

Final diagnosis: Pulmonary hamartoma, overlooked in the initial film
 
Congratulations to Uve, who discovered the nodule with a little help.
 
Teaching point: Remember that overlooking visible findings accounts for 50% of our errors. Using checklists is an excellent way to change an error into a discovery.

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.

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.

Dr. Pepe’s Diploma Casebook: CASE 144 – SOLVED

Dear Friends,
presenting chest radiograph of a 77-year-old man with malaise and weight loss.
What do you see?

This is the last case before the summer. Will see you again in September. Enjoy your vacation!

Click here to see the images


Click here to see the solution

Findings: PA radiograph shows increased opacity of the left hilum (A, arrow), which is due to a mass projected over it, as seen in the lateral view (B, arrows). In addition, there is convexity of the aortopulmonary window (A, red arrow)

The increased hilar opacity (C, arrow) was not visible in a PA radiograph taken six months earlier (D, circle). Convexity of the aortopulmonary window (C, red arrow) was not present at that time.

In the lateral view, the mass (E, arrows) was visible six month earlier, albeit smaller (F, arrow). This progression indicates rapid growth.

Enhanced axial and coronal CT confirms a pulmonary mass invading the aortopulmonary window (G and H, arrows). Lung metastases were present (insert, red arrows)

Diagnosis: lung carcinoma invading the aortopulmonary window

I am presenting this case to discuss the aortopulmonary window (APW), which is a small mediastinal space located between the aortic knob and the pulmonary artery in the PA view (Fig 1A). The APW is normally concave; convexity (Fig 1B) suggests an abnormality that should be studied with enhanced CT.

Fig. 1.

Visibility of the APW is difficult in the elderly, because the superimposed uncoiled descending aorta makes the interpretation more difficult (Fig 2).

Fig 2. 67-year-old man with moderate dyspnea. A calcified lymph node (A-D, red arrows) marks the APW, which is hidden in the PA view by the elongated descending aorta.

Convexity of the APW may be overlooked unless we look specifically at the area (fig 3). The larger the abnormality, the more readily it is detected in the chest radiograph. Subtle changes are more difficult to identify and comparing with previous films is very helpful.

Fig. 3. 55-year-old man consulting for acute chest pain. PA film shows two Hampton humps in the right lower lung (A, white arrows). The left hilum is abnormal (A, red arrow). Enhanced coronal CT confirms the infarcts (B, white arrows), as well as a pulmonary mass (B, red arrow) and lymphadenopathy in the APW (B, yellow arrow). Findings were overlooked in a radiograph taken seven months earlier (C, yellow and red arrows). Proven bronchogenic carcinoma.

Causes that may alter the APW are: tumors, enlarged lymph nodes, aortic aneurysms and increased mediastinal fat. The phrenic nerve crosses this space and a phrenic neurinoma may also grow in the APW, although I have never seen a case.

Enlarged lymph nodes are by far the most common cause of occupation of the APW. They may occur in malignant and non-malignant diseases. They usually coexist with radiographic manifestations of the primary process (Figs 4 and 5).

Fig 4. 59-year-old man with apical LUL carcinoma (A and B, arrows). There is a marked bulge of the APW (A and B, red arrows). Moderate pneumothorax after needle biopsy.

Coronal and axial CT confirm metastatic lymph nodes in the APW (C and D, red arrows)

Fig 5. 33-year-old woman with low-grade fever and malaise. Chest radiographs shows a non-descript infiltrate in the anterior segment of the RUL (A and B, arrows). In addition, there is a prominent bulge in the APW, highly suspicious of lymphadenopathy (A, red arrow). Diagnosis: Hodgkin lymphoma.

In isolated occupation of the APW the etiology cannot be determined in the chest radiograph and enhanced CT should be obtained (fig 6).

Fig 6. Routine check-up in a 60-year-old woman. PA radiograph shows moderate convexity of the APW (A, arrow). Enhanced CT confirms enlarged lymph nodes in the APW (B and C, arrows), mediastinum and hila. Diagnosis: sarcoidosis

Aortic aneurysm is an uncommon cause of convexity of the APW (Fig 7). The abnormality is initially subtle and it becomes more evident as the aneurysm grows (Fig 8).

Fig 7. 78-year-old man without significant symptoms. PA radiograph shows a mediastinal mass protruding at the level of the APW (A and C arrows). The mass is also evident in the lateral view (B and D, arrows).

Radiographs taken five years earlier did not show the abnormality (E and F, circles).

Enhanced axial and coronal CT demonstrate that the mass represents a saccular aneurysm arising from the aortic arch (G and H, arrows).

Fig 8. 78-year-old man after a fall. PA radiograph shows numerous rib fractures (A, white arrows). An additional finding is a mediastinal opacity at the APW (A, red arrow), also visible in the lateral view (B, red arrow).

Comparison with previous films shows a normal APW in 2007 and progression of the opacity over a three-year period (arrows).

Enhanced CT shows that the opacity represents a partially thrombosed aneurysm arising from the inferior aspect of the aortic arch (C-D and E, arrows).

Last but not least, we should remember that mediastinal fat is an innocuous cause of convexity of the APW (Fig 9).

Fig 9. Asymptomatic 57-year-old man with superior mediastinal widening (A, arrow) and discrete convexity of the APW (A, red arrow). Coronal CT shows that the changes are due to mediastinal fat (B and C, arrows).


Follow Dr. Pepe’s advice:

1. Convexity of the APW suggests underlying pathology.

2. Enlarged lymph nodes are the most common cause of a convex APW.

3. Aneurysm and mediastinal fat may also enlarge the APW

Dr. Pepe’s Diploma Casebook: CASE 143 – The wisdom of Dr. Pepe – SOLVED

Dear Friends,

This case belong to the section “The wisdom of Dr. Pepe”, in which an (useful?) aphorism ends the presentation.

I am presenting a routine PA radiograph in an asymptomatic 79-year-old woman operated on for a breast DCIS five years ago. PA radiograph taken five years earlier is shown for comparison. More images will be shown on Wednesday.

Diagnosis:

1. Granulomas
2. Metastases
3. Primary lung tumor(s)
4. Any of the above

Click here to see the images

Dear Friends,

showing CT images with and without contrast enhancement.

What would your diagnosis be?

1. Carcinoma
2. Active TB
3. Fibrous lung tumor
4. Any of the above

Click here to see the CT


Click here to see the answer

Findings: The PA chest radiograph shows two obvious small nodules in the left middle lung field (A, circle), not present five years earlier (B). In my experience, two nodules close together are usually granulomas. But in this case we have another finding: a subtle bulge in the left hilum (A, arrow), not visible in the previous film, highly suspicious of hilar adenopathy. This changes the diagnostic orientation and makes us think of an active process.

Unenhanced axial CT shows an hourglass-shaped pulmonary lesion (C and D, arrows) that simulated two nodules in the chest radiograph. The lesion enhances after contrast injection and contains a large arterial vessel (E, arrow). Non-enhancing lymph nodes are visible in the left hilum (F, arrow).
Although all three diagnoses offered in the blog can cause hilar adenopathy, the vascularity of the lesion points to a tumor.

PET-CT shows faint uptake of the primary lesion and the hilar lymph nodes (G and H, arrows). A needle biopsy (I, arrow) came back as an atypical small-cell tumor.

The patient was treated with chemotherapy and radiotherapy, with a good response of the primary tumor (J, arrow) and lymph nodes (K, circle).

Final diagnosis: SCLC with hilar metastasis and a good response to QT and RT

Discussion: I just finished reading “The subtle art of not giving a f*ck“ and there is an enlightening (and sadly true) chapter entitled “You are not special”. In this particular case I was feeling special, as I diagnosed a malignant pulmonary fibroma based on a single case seen 20 years ago (see below) because of the similarity of the vascular pattern in the two cases. After 50 years of practice, I forgot a basic principle: common conditions are, well, common. I’m showing this case to remind you that when faced with a diagnostic dilemma you should first consider common options rather than uncommon ones.

To redeem myself, I am showing my only case of fibrous tumor of lung in a 37-year-old woman with hemoptysis. The PA radiograph shows a well-defined paramediastinal nodule (A, arrow). Enhanced coronal and sagittal CT confirms the intrapulmonary location of the nodule, which has a large arterial vessel in the center with an aneurysm at the end (B and C, arrows).

Surgery confirmed a fibrous tumor of the lung.

Two bits of information about fibrous tumor of the lung: It is a very unusual spindle-cell tumor with the same histology as fibrous tumors of pleura, and like them, it has malignant potential. It is usually asymptomatic and is seen as a rounded or ovoid nodule of varying size. Immunohistochemistry is important for the diagnosis.


Follow Dr. Pepe’s pearls of wisdom:

Always consider that what you are seeing is a rare manifestation of a common disease rather than a common manifestation of a rare disease.

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?

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

LOSS OF VOLUME OF LUL + SURGICAL STAPLES = LUL LOBECTOMY

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.

CASE 1:

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.

CASE 2:

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.

CASE 3:
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.