Discussion
CPAM, once referred to as congenital cystic adenomatoid malformation
(CCAM), is an uncommon, developmental lung anomaly of unknown cause,
presenting as cystic changes to the terminal bronchioles (5). There are
a few differential diagnoses to CPAM that include bronchogenic cysts
(BC), congenital lobar emphysema (CLE), and bronchopulmonary
sequestration (BPS) (1). Antenatally, CPAM can cause some complications
in the fetus, the most important of which is Hydrops Fetalis due to the
compressing of the mass on other structures, which usually requires an
emergency cesarean section (3). At birth, 70% of CPAM are asymptomatic.
Among antenatally diagnosed patients, 70% of antenatally diagnosed CPAM
are asymptomatic; while the other 30% cause neonatal respiratory
distress, with 10% have severe respiratory distress requiring assisted
ventilation (1). In some cases, CPAM remains unrecognized until
adolescence or later life when complications, such as recurrent
pulmonary infections, pneumothorax and lung abscess, start to happen
(5). In our case, there was symptomatic, antenatally diagnosed CPAM,
associated with Hydrops Fetalis antenatally (requiring caesarean
delivery), and severe respiratory distress postnatally (requiring
neonatal intensive care unit). Therefore, left lower lobectomy was
decided, and open surgery was chosen over thoracoscopy due limited
resources (lack of equipment and expert hands). The management of CPAM
is highly debatable, and varies from administering maternal
betamethasone prenatally (to decrease the size of large CPAMs and
reverse hydrops) to minimally invasive or even open surgical resection
postnatally, with the most controversial area remains the postnatal
management of asymptomatic cases. Prophylactic lung resection in
asymptomatic patients is sometimes done, and has advantages that include
reduced risk of infection, malignancy and decreased complication rate,
while disadvantages include mortality and morbidity associated with
operation and cancer risk despite excision. Due to the low incidence and
wide spectrum of manifestation of CPAM, it is not surprising that the
quality of the evidence on management styles is generally poor (6).
David et al (2016) proposed prenatal Fig.5 (A) and postnatal Fig.5 (B)
management algorithms (2). A meta-analysis by Naser and Bass (2012),
suggested that thoracoscopic resection is a safe and feasible
alternative to open resection of congenital lung lesions in experienced
hands, and no differences between thoracotomy versus thoracoscopy for
management of CPAMs were observed in terms of overall complications and
the duration of surgery. However, days with chest tube in place and
length of hospitalization period were longer after open surgery (7).