CHEST INTERESTING CASE THUMBNAIL
Chest

Chest 15

02 Sep, 2026

INTERESTING CASES ARE BEST VIEWED ON A DESKTOP DEVICE

Tricuspid valve MSSA endocarditis. Admitted with new distributive shock and high fever. What's the diagnosis? This is a large study so the images may take longer to load.

Salient findings:

  • Widespread diffuse bilateral lung infiltrates and nodules with multiple cystic and cavitating areas centrally.
  • Many of these are thick-walled, some displaying internal septations and fluid levels.
  • Bilateral pleural effusions, greater on the right.
  • Increased right heart and pulmonary artery pressures with pulmonary conus and right atrial enlargement.
  • Mild cardiomegaly.
  • Tracheostomy tube approximately 4.7 cm proximal to the carina.
  • Multiple prominent mediastinal lymph nodes, likely reactive, but no overt lymphadenopathy.
  • Left IJV central line with the tip lying in the proximal SVC.

Principal diagnosis: Septic emboli with multiple pulmonary abscesses

Learning points:

  • What is septic embolisation?
    • The embolisation of infectious particles in the form of intravascular thrombi containing microorganisms.
  • Underlying origins?
    • Right-sided infective endocarditis, especially involving the tricuspid valve.
    • Soft-tissue infection in the presence of an associated septal defect, allowing entry into the pulmonary circulation.
    • Infected lines or catheters, e.g. CVC.
    • Dental disease.
    • Infected DVTs, especially jugular vein septic thrombophlebitis, also known as Lemierre’s syndrome.
  • Culprit organisms
    • Staphylococcus aureus
    • Klebsiella pneumoniae
    • Pseudomonas aeruginosa
    • Fusobacterium necrophorum (seen in Lemierre’s syndrome)
  • Imaging features in septic emboli
    • Multiple pulmonary nodules, which can cavitate.
    • Small subpleural pulmonary infarcts.
    • Pleural effusion.
    • Ground-glass opacity or consolidation often surrounds the nodule.
  • Differential diagnoses for cavitating pulmonary nodules
    • Lung neoplasm or pulmonary metastases, particularly from squamous cell carcinoma primaries.
    • Granulomatosis with polyangiitis (GPA).
    • Sterile cavitating nodules or granulomas—called necrobiotic nodules—seen in autoimmune or inflammatory conditions such as rheumatoid arthritis (RA) and inflammatory bowel disease (IBD).

Test Your Knowledge

1. A 58-year-old man with a 40-pack-year smoking history presents with haemoptysis and weight loss. CT chest demonstrates a 3.5 cm thick-walled cavitating mass in the right upper lobe with irregular inner and outer margins. There is associated right hilar lymphadenopathy. Which is the most likely diagnosis?

Squamous cell carcinoma is the primary lung malignancy classically associated with cavitation, particularly when the lesion is central or upper-lobe predominant. A thick, irregular cavity wall and associated lymphadenopathy favour malignancy. Adenocarcinoma can also cavitate but does so less characteristically. 

2. A 46-year-old woman presents with haemoptysis, sinus symptoms and deteriorating renal function. CT chest demonstrates multiple bilateral pulmonary nodules of varying sizes, several of which demonstrate cavitation. Which diagnosis is most likely?

GPA classically produces multiple bilateral pulmonary nodules or masses that may cavitate. The combination of upper respiratory tract disease, pulmonary abnormalities and renal involvement is particularly characteristic. Nodules may change rapidly in size or number on serial imaging. 

3. A 35-year-old intravenous drug user presents with fever, pleuritic chest pain and haemoptysis. CT pulmonary angiography demonstrates multiple bilateral peripheral pulmonary nodules, several showing cavitation. Some nodules are wedge-shaped and extend to the pleural surface. Which is the most likely underlying cause?

Septic pulmonary emboli typically appear as multiple peripheral nodules, often at different stages of cavitation, with a lower-lobe/peripheral distribution. Wedge-shaped pleural-based opacities may be seen. In right-sided infective endocarditis—particularly involving the tricuspid valve—is an important source. Other high risk groups include intravenous drug users.