Follow up to Abnormal CXR (Sequestration)

I thought this was an interesting case. It is actually a case of pulmonary sequestration. You probably know that there is intralobar and an extralobar sequestration. The former occurs within the visceral pleura of normal lung tissue. It doesn't communicate with the tracheobronchial tree. It looks cystic on CT. The CT shows the cystic-appearing area involving a region of the posterior basilar segment, right lower lobe. In other slices not shown, it was about 8 x 4 cm. If you saw the whole CT and/or looked at the CT reconstruction, you would note that there is an abnormal systemic artery extending from the lateral aspect of the aorta into this portion of the lung. Venous drainage is to the left atrium.