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


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.


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.

12 thoughts on “Dr. Pepe’s Diploma Casebook – The art of interpretation – CASE 146 – SOLVED

  1. Good morning!!

    Subtle less of volume of the left hemithorax.
    There are signs of alveolar fiiling in the left upper lobe [better seen in the lateral view- increased parahilar density] perhaps with paratracheal adenopathies and a Viral infection?

  2. Hi,

    Frontal and lateral chest radiograph of skeletally mature patient provided.
    Frontal chest xray- patient slightly rotated to his left .Adequate inspiratory effort. adequate exposure factors.
    Prominent second mogul of left cardiomediastinal border- Can be due to aortopulmonary window lymph node.
    Assymetrical hila with increased left hilar density- infective cause- can be Pulmonary tuberculosis.
    neoplastic cause – can be bronchogenic carcinoma.
    Sharp Costo/cardio-phrenic angles. No cardiomegaly. Visualised bony structures appears normal.

    Suggest CT thorax for further imaging.

  3. Good morning

    Left upper lobe parahilar small cavitary lesion with more or less uniform wall and subtle surronding pulmonary changes

  4. Subtle perihilar haze more on the left, suspicious numerous small nodules in both lungs, AP window convexity and left hilar fullness suggestive of lymphadenopathy – differential would include infection (couldn’t exclude primary TB, or some other less typical causative organisms), lymphoma.

  5. Good morning!
    In the CT there is an alveolar filling in the LLL with aereal bronchogram. in the left hilum there is a peribroncho-vascular thickened. With this I think in infection.

    In the coronal images there is an obliteration of the right cardio-phrenic angle… I think in ML’s atelectasis but there isn’t loss of volume…

  6. You all will know the answer tomorrow. In the meantime I want to congratulate the early and correct interpretation of RGD and Arunkumar.

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