Pediatric Round Pneumonia

  • Etiology: Streptococcus pneumoniae in 90%
  • Imaging:
    — Due to absence or poor development of collateral airways due to immature lung anatomy
    — Inflammation spreads centrifugally giving round appearance
    — In superior segments of lower lobes
    — Solitary round opacity that is a mean of 3-4 centimeters in size
  • Note: Collateral airways allow ventilation of alveoli through the channels bypassing the normal airway but are poorly developed in infants
  • Note: Channels of Lambert and pores of Khan for intralobular collateral circulation, Pathway of Martin for interlobular circulation
  • DDX: Pulmonary mass so must get CXR 1 month post treatment to document resolution of mass and document it is not a malignancy
  • Complications:
  • Treatment: Antibiotics
  • Clinical: Seen in less than 8 years old and peaks at 3-5 years old

Radiology Cases of Round Pneumonia

CXR of round pneumonia
Initial CXR PA (above left) shows a large round opacity located medially in the right hemithorax which is located posteriorly on the lateral (above right) over the spine (spine sign). CXR PA obtained 5 days later (below) shows interval resolution of the mass.

CXR of bacterial pneumonia in the lingula
CXR PA (left) shows a round opacity in the lateral aspect of the left lung that on the lateral (right) projects over the heart.

CXR of pediatric round pneumonia
CXR AP (left) and CXR lateral (right) show a round lesion in the superior aspect of the right lower lobe.