Pulmonary sequestration is a cystic or solid mass composed of nonfunctioning primitive tissue that does not communicate with the tracheobronchial tree and has anomalous systemic blood supply. It is a type of congenital thoracic malformation. It may present as a lung infection on physical examination and chest imaging. Its blood supply is from systemic circulation rather than the pulmonary circulation. Multiple feeding vessels may be present in 15-20% of cases. The 2 forms of pulmonary sequestration are intrapulmonary, which is surrounded by normal lung tissue, and extrapulmonary, which has its own pleural investment. Other congenital malformations may be present.