Congenital Anomalies

Lung Development Defects - Embryo's Oopsies

• Pulmonary Agenesis: Complete absence of lung tissue & bronchus.
• Pulmonary Aplasia: Rudimentary bronchus present, no lung parenchyma.
• Pulmonary Hypoplasia: ↓ lung volume & weight for gestational age; ↓ acini & alveoli.
  • Often secondary to conditions limiting thoracic space or ↓ amniotic fluid.

  ⭐ Pulmonary hypoplasia is strongly associated with oligohydramnios (e.g., Potter sequence) and congenital diaphragmatic hernia.

• Causes of Hypoplasia:
  • Congenital Diaphragmatic Hernia (CDH): Abdominal contents in thorax.
  • Oligohydramnios: Insufficient amniotic fluid (e.g., renal agenesis - Potter sequence).
  • Chest wall abnormalities: e.g., Jeune syndrome.
  • Reduced fetal breathing movements.

Cystic Anomalies - Bubbly Troubles

• Developmental cystic lung lesions; often present with a "bubbly" appearance on imaging.

Congenital Pulmonary Airway Malformation (CPAM)

• Hamartomatous proliferation of terminal bronchioles; typically communicates with the airway.
• Presents: Neonatal respiratory distress, recurrent infections. Risk: Pneumothorax, malignancy.

⭐ Congenital Pulmonary Airway Malformation (CPAM) Type 1 is the most common type and generally has a good prognosis.

• Results from abnormal budding of the ventral foregut or tracheobronchial tree.
• Typically mediastinal or intrapulmonary; lined by ciliated columnar epithelium; wall may contain cartilage, smooth muscle, and bronchial glands.
• Usually solitary, round/oval, fluid or mucus-filled; does NOT typically communicate with the airway.
• Presents: Often asymptomatic; may cause symptoms due to compression (e.g., dyspnea, dysphagia) or infection.

Sequestration & CLE - Lost & Found Lung Bits

⭐ Pulmonary sequestrations are characterized by non-functional lung tissue that receives systemic arterial blood supply, not from pulmonary arteries.

Pulmonary Sequestration: Non-functional lung tissue, no normal airway connection; systemic arterial supply.

• Types: Intralobar (ILS) & Extralobar (ELS).

Congenital Lobar Emphysema (CLE):

• Progressive overdistension of lobe(s); LUL > RML > RUL.
• Cause: Bronchial check-valve (cartilage defect).
• Symptoms: Neonatal respiratory distress, wheezing.
• CXR: Hyperlucent lobe, mediastinal shift, compressed lung.

Tracheoesophageal Fistula - Wrong Pipes

• Abnormal connection between trachea & esophagus; often with Esophageal Atresia (EA).
• Associations: VACTERL (Vertebral, Anal, Cardiac, Tracheo-Esophageal, Renal, Limb defects), Trisomy 13, 18, 21.
• Clinical Triad (infants):
  • Choking/coughing/cyanosis with feeds
  • Excessive salivation/drooling
  • Respiratory distress
• Diagnosis: Inability to pass NG tube; X-ray (coiled NG tube, air in stomach for distal TEF).

⭐ The most common type of tracheoesophageal fistula is Esophageal Atresia with a distal TEF (Gross Type C, ~85% of cases), often presenting with polyhydramnios in utero.

High‑Yield Points - ⚡ Biggest Takeaways

• Pulmonary Sequestration: Non-functional lung, systemic arterial supply, no bronchial connection.
• CPAM: Hamartomatous cystic airway lesion; Type 1 (large cysts) best prognosis.
• Bronchogenic Cysts: Mediastinal foregut cysts, respiratory epithelium lining.
• CDH: Bochdalek type (posterolateral) commonest, causes pulmonary hypoplasia.
• TEF: Esophageal atresia with distal fistula (Type C) most common; polyhydramnios link.
• Pulmonary Hypoplasia: Incomplete lung development, from oligohydramnios or CDH.
• CLE: Progressive lobar overinflation, due to bronchial cartilage defect.