Shoe, scimitar or sequestration: a shifting spectrum.

Congenital abnormalities of the tracheobronchial tree are rare causes of recurrent chest infections in childhood. A case is described which shows some typical features of horseshoe lung. More detailed imaging revealed complete separation of the right and left pleural cavities and the malformation represents part of the sequestration spectrum. The case emphasises the need for careful evaluation of the pulmonary arteries, veins, bronchi and oesophagus, particularly prior to surgery.