intervention if the following if hydrops fetalis is present. Hydrops is a sign of in utero
cardiac failure due to the physiologic effects of the space occupying lesion in the thorax.
On ultrasound, signs of hydrops include nuchal or scalp edema, pleural effusion,
pericardial fluid, overall fetal edema. For congenital cystic airway malformations
(CCAM), there is literature to support that administration of steroids while the fetus is in
utero may shrink the lesion. Thoracoamniotic shunts have been used to drain the fluid
within the fetal cyst to alleviate signs of hydrops.
Embrology
The classic embryology and histology of congenital cystic malformations of the
lung is currently being challenged. In the past, CCAM’s, which may also be referred to
as congenital pulmonary airway malformations (CPAM) were differentiated from
sequestrations by the presence of systemic blood supply in the latter diagnosis. There
was a school of thought that CCAM’s were truncated maldeveloped airways and
pulmonary sequestrations are alveolar units that developed without airway connections.
However, there is more evidence that these lesions often overlap.
Bronchopulmonary sequestrations are classified as either intralobar and extralobar.
Sequestrations consist of non-functional pulmonary tissue that does not directly
communicate with the bronchial tree. Extralobar sequestrations are invested in their
own plural membrane, while intralobar sequestrations are a lobe of the lung, usually the
lower lobe. Extralobar and intralobar sequestrations have a systemic arterial blood
supply. Venous return is through the systemic or pulmonary venous systems. The
systemic vessels associated with extralobar sequestraions may be large, thin walled,