This shows a section of the left lower lobe; in the basal area there are several cystic spaces up to 2
cm across. The surrounding lung shows some collapse.
This man, at the age of 16, had a respiratory infection; on X-ray multiple cystic areas
were seen in the left lower lobe. Two years later he had a further infection and again the cystic
spaces were demonstrated radiologically. A bronchogram showed some clouding of the basal
bronchial structures but no communication with the cystic spaces; a thoracic aortogram showed a
single large vessel arising from the thoracic aorta about the level of the 11th thoracic vertebra and
passing upwards and laterally to supply the abnormal area. A diagnosis of sequestration was made
and the lobe removed. Histologically the cysts were seen to be lined by ciliated bronchial
epithelium and in some cysts there was a florid growth of fungus.