These features are consistent with round pneumonia. 

Round pneumonia is a type of pneumonia usually only seen in pediatric patients. They are well defined, rounded opacities that represent regions of infected consolidation, it often indicates streptococcal pneumonia.

Round pneumonias are well-circumscribed parenchymal opacities, they tend to have irregular margins. They most commonly occur in superior segments of lower lobes and in the majority of cases (98%), they are solitary. Air bronchograms are often present.