2. CONGENITAL CYSTIC DISEASES OF THE
LUNG
• This group of entities is characterized by congenitaly cystic
pulmonary tissue.
• Although the exact embryogenesis of various forms is
disputed, all result in aberrant differentiation of
bronchi, bronchioles, alveoli, and pulmonary vasculature.
• All of these pathologies are causing neonatal respiratory
distress
• The major forms of congenital cystic lung disease include:
1) Pulmonary
sequestration,
2) Bronchogenic cyst
3)Congenital cystic adenomatoid malformation
4) Congenital lobar emphysema.
3. PULMONARY SEQUESTRATION
• Pulmonary sequestration is a condition in which a
segment or lobe of lung tissue has no bronchial
communication with the normal tracheobronchial
tree.
• The arterial blood supply is from a systemic
vessel.
• This vessel often arises from the aorta.
• The venous return is usually through the
pulmonary veins but may be to the systemic
venous system.
4. Types
1)Extralobar sequestration
Is separate from the normal lung and has its own visceral
pleura. Left side affected in 90% of the cases .
Usually found in the posterior costophrenic angle. Repeated
infections in the lesion may develop if a communication with
the foregut is present.
Surgical resection is indicated for symptomatic patients and
when the diagnosis is in question.
2) Intralobar sequestration
is situated within normal lung parenchyma.
5.
6. Diagnosis
• In 50% to 65% of the cases, they are associated with other
anomalies, namely congenital diaphragmatic
hernia, eventration, esophageal duplications, and
tracheoesophageal fistula.
• Boy:girl ratio of 3:1.
• Children and young adults with recurrent left-lower-lobe
pneumonia should be suspected of having an intralobar
sequestration.
• Postnatal chest radiography could not always identify the
lesion, but CT scanning or magnetic resonance imaging (MRI) are
diagnostic.
• Treatment consists of a lobectomy.
• Careful identification of the arterial supply and suture ligation is
necessary
7. BRONCHOGENIC CYSTS
• Bronchogenic cysts originate in abnormal diverticuli of the
lung bud in the third to sixth week of fetal life.
• They are usually located adherent to the left mainstem
bronchus or carina and are extrapulmonary in location
within the middle mediastinum.
• Abnormal budding in the distal tracheobronchial tree
causes intraparenchymal cysts.
• The cyst wall contains all elements of the normal bronchus:
columnar and mucus-secreting epithelium, smooth
muscle, elastic tissue, and cartilage.
8.
9. BRONCHOGENIC CYSTS
• Most children with obstructing cysts who present
in early infancy have moderate to severe
respiratory distress and clinical signs of airway
obstruction such as stridor, wheezing, and
cyanosis.
• Cysts may be air filled, fluid filled, or exhibit air–
fluid levels.
• An air-filled bronchogenic cyst on a chest
radiograph is sharply defined and round.
10. BRONCHOGENIC CYSTS
• The cyst can expand rapidly; if it ruptures, it
may produce a tension pneumothorax.
• Surgical resection using an open or minimally
invasive technique is indicated for all
bronchogenic cysts in infants and children.
11. CONGENITAL CYSTIC ADENOMATOID
MALFORMATION
• Congenital cystic adenomatoid malformation
(CCAM) is a rare form of congenital cystic disease
of the lung.
• The lesion is caused by an arrested alveolar
development associated with a proliferation of
terminal bronchioles in the affected lobe.
• These bronchioles are lined by columnar or
cuboidal epithelium and have soft walls. Air
enters and then is trapped, causing cystic dilation
of the bronchioles.
12. CONGENITAL CYSTIC ADENOMATOID
MALFORMATION
• The entire malformation may cause a mediastinal
shift to the opposite side and compressive
atelectasis of otherwise normal adjacent lung
tissue.
• The newborn with a large CCAM presents with
severe respiratory distress secondary to the
space-occupying mass, compression of the
contralateral lung, and the inadequate volume of
functioning lung tissue at the time of
presentation.
• The contralateral lung may also be hypoplastic.
14. CONGENITAL CYSTIC ADENOMATOID
MALFORMATION
• Radiographic diagnosis of the mass may be
difficult; it may be confused with congenital lobar
emphysema (CLE).
• Emergency thoracotomy and lobectomy is often
lifesaving. In the older child or adult, surgical
resection is required to remove the source of
recurrent pneumonia.
• Resected patients have a good prognosis. Less
commonly, patients with CCAM present in
childhood with a history of recurrent pulmonary
15. CONGENITAL LOBAR EMPHYSEMA
• Congenital lobar emphysema is a surgically
correctable cause of severe respiratory distress in
infancy.
• Affected infants may present with respiratory
distress that is mild or severe, precipitated by
crying, feeding, or, on occasion, respiratory
infection.
• Boys are more often affected than girls. The left
upper lobe is most frequently involved, followed
by the right middle lobe
16.
17. CONGENITAL LOBAR EMPHYSEMA
• The pathology of CLE has been attributed to deficient
bronchial cartilage in the affected main
bronchus, which causes endobronchial proliferation of
mucous membranes and subsequent obstruction.
• Deficient cartilage (25% of cases), endobronchial
obstruction (13%), extrinsic compression of the
bronchus by an anomalous vessel (1%), and diffuse
lobar bronchial abnormalities (4%) have all been
demonstrated; no cause has been found in 50% of
cases.