Pulmonary sequestration. A report of an unusual case and a review of the literature

A case of extralobar sequestration with findings indicating a pulmonary origin is reported. The literature has been reviewed and evidence presented that intra- and extralobar sequestration are variants of the same abnormality and that the systemic artery is an associated anomaly. From the evidence available at present the pathogenesis of this anomaly is best explained as an abnormality of bronchial and foregut budding resulting from failure of normal embryonic organizer control.