Congenital lobar emphysema (CLE) is the overinflation of one or more lung lobes, present from birth with a lung histologically normal. The left upper lobe is most frequently affected. 

The causes are varied but are all linked to abnormal intrauterine development. The common mechanism includes obstruction of a lobar or segmental bronchus with valve mechanism that results in gas trapping with overdistension of the lung and tissue destruction.

Acknowledgement: Dr Maurizio Salvi.