A 70-year-old woman had never smoked and had no breathing complaints when a CT scan turned up a mass of roughly 3 centimeters at the bottom of her left lung. With a sibling who had lung cancer and other cancers in her family, the finding raised obvious concern.
It was not cancer. Imaging traced the blood supply of the triangular mass to an artery branching straight off her aorta, the hallmark of pulmonary sequestration. In this rare congenital abnormality, a piece of lung tissue forms without a normal airway connection and draws blood from the body's main circulation instead of the pulmonary arteries.
