Post-pneumotic pneumatocele

Q: Describe the abnormality on the chest radiograph. show answer

A: There is a well-defined cystic lesion in the right upper zone. It has a thick wall and an air-fluid level.

Q: What lobe is the lesion in and how can you place it there? show answer

A: The lesion is in the upper zone and on the AP radiograph it is above the horizontal fissure; it is therefore located in the right upper lobe.

Q: For radiology-geek bonus-points what is the segmental anatomy of the right upper lobe? show answer

A: The right upper lobe is split into 3 bronchopulmonary segments: the anterior, posterior and apical segments.

Q: What is the differential diagnosis for this cyst with its air-fluid level. show answer

A: The differential diagnosis includes a pneumatocoele, abscess and a congenital cystic lung lesion

Q: What is the most likely diagnosis? show answer

A: The most likely diagnosis is that of a pneumatocele.

Q: What is the likely underlying pathophysiology of the lesion. show answer

A: Pneumatocoeles are usually post-pneumonic, often following Staph. aureus infection.

Q: The child is treated with appropriate antibiotic therapy for the underlying Staph. aureus infection. What are the treatment options for the pneumatocele? show answer

A: Usually, post-pneumonic pneumatoceles resolve after about 6 weeks. So, aside from a repeat film, nothing is required.

Q: In what situations might surgical intervention be required? show answer

A: If the pneumatocele exerts enough mass-effect to cause cardiovascular or respiratory compromise or if it ruptures resulting in a non-drainable pneumothorax.