Case 1556 Round pneumonia

H J Williams, R C Bhatt

Paediatric Radiology Section: 2002, Jun. 27 Published:

11 month(s), femalePatient:

Clinical History

A previously-well child presented with poor feeding, fever, tachypnoea and cough of 2 days'

duration.

Imaging Findings

A previously-well child presented with poor feeding, fever, tachypnoea and cough of 2 days'

duration. Chest x-ray showed a well-defined rounded opacity in the left lower zone, which did not

obscure the left heart border, localising it to the left lower lobe. A diagnosis of round pneumonia

was made and antibiotic therapy commenced. The child made a rapid and complete recovery.

Discussion

Acute pneumonia in children may produce a rounded or spherical density on chest radiographs,

often termed 'round pneumonia'. This manifestation is found almost exclusively in children of less

than 8 years of age. The typical clinical presentation is with an acute febrile illness, respiratory

distress and cough. The cause is almost always bacterial, usually pneumococcal or staphylococcal in

origin and the round shape is thought to be a result of centrifugal spread of the multiplying

organisms through the pores of Kohn and the channels of Lambert. The opacities are almost always

posterior and often located in a lower lobe. Initially the lesions are well defined, but lose definition

and then clear rapidly with appropriate antibiotic therapy. An air-bronchogram is seen in

approximately 20% of cases of round pneumonia. Radiographically, round pneumonia may mimic a

primary or metastatic lung tumour, or a posterior mediastinal mass e.g. neuroblastoma. In the

setting of an acute febrile illness with respiratory symptoms an infectious aetiology is much more

likely and this should prompt appropriate treatment without unnecessary investigations for

neoplasm. Round pneumonia in the older child or adult suggests immunodeficiency or an atypical

pathogen such as a fungus.

Final Diagnosis

Round pneumonia

Figures

Figure 1 AP chest radiograph

AP chest radiograph demonstrating a well-defined rounded opacity in the left lower zone(left lower lobe).

Area of Interest: unknown; Imaging Technique: AP chest radiograph;

MeSH

[C08.730.610]PneumoniaInflammation of the lungs.

[C08.730.610.540]Pneumonia, BacterialPneumonia caused by various species of bacteria. Bacterial pneumonia commonly results from

bronchogenic spread of infection following microaspiration of secretions. The largest category of

this disease arises from community-acquired pneumonias.

References

[1] Blickman H. Chest (chapter 2). In Blickman JG, Blickman H. Paediatric Radiology: The

Requisites, Second Edition. Mosby, St Louis, p 37. (1998)

[2] Hedlund GL, Griscom NT, Cleveland RH, Kirks DR. Respiratory System (chapter 7). In Kirks

DR (Ed). Practical Paediatric Imaging: Diagnostic Radiology of Infants and Children, Third

Edition. Lippincott-Raven, Philadelphia, p 639. (1998)

[3] Franquet T. Imaging of pneumonia: trends and algorithms. Eur Respir J 2001 Jul;18(1):196-208.

[4] Wagner AL, Szabunio M, Hazlett KS, Wagner SG. Radiologic manifestations of round

pneumonia in adults. AJR Am J Roentgenol 1998 Mar;170(3):723-6.

Citation

H J Williams, R C Bhatt (2002, Jun. 27)

Round pneumonia {Online}URL: http://www.eurorad.org/case.php?id=1556