Congenital cystic lesions of the lung

1. Dr. K Khaing Saw Lwin
MBBS,MRCSEd,
MMedSc(Thoracic Surgery)

2.  Lower respiratory system begins to form in
4th week of gestation as a median outgrowth
from the caudal end of the ventral wall of the
primitive pharynx.
 This outgrowth known as the laryngotracheal
groove evaginates to form the laryngotracheal
diverticulum, which elongates to form the lung
bud.
 Tracheoesophageal folds fuse to form the
tracheoesophageal septum, which separates
the foregut from the laryngotracheal
diverticulum

3.  Lung bud divides into two bronchial buds in 5th
week & enlarge to form the primary bronchi
 These soon divide into secondary bronchi and
tertiary bronchi by the 7th week
 By 24 weeks, 17 orders of branches have formed
 The endoderm lining of the laryngotracheal tube
gives rise to the lower respiratory epithelium
 The mesenchyme surrounding the laryngotracheal
tube gives rise to the connective tissue, cartilage,
muscle, and vessels

4. Congenital Cystic Adenomatoid
Malformation (CCAM)
Bronchogenic cyst (BC)
Pulmonary sequestration (PS)
 Congenital lobar emphysema (CLE)

6.  Congenital Cystic Adenomatoid Malformation
(CCAM) aka as congenital pulmonary airway
malformation (CPAM)(A spectrum of cystic
and solid lesions of the lung identified
histologically)
 there is an overgrowth of terminal bronchiolar-
type tubular structures and a lack of mature
alveoli
 Composed of cartilage, smooth muscle, and
bronchial glands containing columnar and
cuboidal epithelial cells
 25% of all congenital lung anomalies (second
only to congenital lobar emphysema)

7. Normal vascular development
affected area communicates with the
normal airway
Usually only one lobe (a solitary lesion)

8.  An adenomatoid increase of terminal
respiratory bronchiole-like structures lined by
ciliated columnar epithelium occurs.
Interspersed cysts may resemble immature
alveoli. The connective tissue stroma
contains disorganized elastic tissue and
smooth muscle.
 The mucosa of cysts lined with bronchial-type
epithelium may show polypoid overgrowth
projecting into the lumen of the cysts.

9. Bronchial mucoserous glands and
cartilaginous plates are absent throughout
the cystic parenchyma
Occasional groups of alveolar cysts may
be lined with mucus-secreting cells that
resemble intestinal mucosa and do not
resemble normal bronchial cells

10. Manifestations ---neonatal acute respiratory
distress with or without associated lung
infection
DDx- congenital diaphragmatic hernia

14. Dx by CT
associated anomaly --- pectus excavatum,
cardiac and
pulmonary vessel malformations
The Stocker classification( treatment
planning)

17.  rare
 develop as a unilocular entity within the
parenchyma, most commonly in the left
lower lobe
 Blood supply- aberrant systemic artery
 lined with mucus-secreting
pseudostratified columnar epithelium.

18.  usually communicates with a bronchus.
 a variant of cystic adenomatoid
malformation
may also result from entrapped lung blood,
with subsequent air trapping after the
blood has been resorbed
Symptoms ---
chronic cough
Respiratory distress
frank sepsis

19. Dx- Cyst // Abscess --- presence of a
systemic artery feeding the cyst is
diagnostic.
Failure of the cyst to completely collapse
with tube drainage
Differential diagnosis ---
1. congenital diaphragmatic hernia and
2.postpneumonic staphylococcal
pneumatoceles

20. Treatment
Uncomplicated case --- observation
Indication for intervention
1. infected cyst --- preliminary antibiotic
treatment is followed by resection once
sepsis subsides
2. expanded cyst
3. symptomatic.
Tx options
• Segmentectomy
Lobectomy
Pneumonectomy

22. Nonfunctioning Cystic mass of lung
parenchyma without communication with
TB tree and with an anomalous systemic
blood supply
 Typically, these lesions have a single large
feeding vessel arising from the aorta
Venous drainage is variable and can be
systemic, bronchial, or azygous

23. 1. Intralobar: invested by the same pleura,
commonly at LL basilar segments (left
>right)(majority )
2. Extralobar: outside the investing parietal
pleura, commonly found in the lower
hemithorax
Associated anomalies--- congenital
diaphragmatic hernia, eventration,
esophageal duplications, and
tracheoesophageal fistula

25.  Results from obstruction of a lobar bronchus
progressive airtrapping and overinflation.
– Intrinsic (bronchomalacia, webs,
stenosis) - - Extrinsic (Bronchogenic cyst,
vascular structures)
• Histological, the lung parenchyma is normal
with enlargement of the airspaces only
• CLE commonly affects the upper lobes
particularly the left