Pediatric Surgery: Pulmonary Cysts

Pulmonary Cysts

Presentation

  • Fetal Hydrops
  • Recurrent Infection/Pneumonia
  • Cough & Hemoptysis
  • Pneumothorax
  • Respiratory Distress
  • Failure to Thrive
  • Risk for Malignancy:
    • Young Children/Infants: Pulmonary Blastoma & Rhabdomyosarcoma
    • Older Children/Adults: Bronchioalveolar Carcinoma

Causes

  • Congenital Pulmonary Airway Malformation (CPAM)
    • Formerly Congenital Cystic Adenomatoid Malformation (CCAM)
  • Pulmonary Sequestration
  • Congenital Lobar Emphysema

Congenital Pulmonary Airway Malformation (CPAM)

  • Formerly Congenital Cystic Adenomatoid Malformation (CCAM)
  • The Most Common Congenital Lung Lesion
  • Definition: Hamartomatous Adenomatous & Cystic Lesions
  • Has Tracheobronchial Tree Connections Although Does Not Have Normal Gas Exchange Function

Bronchopulmonary Sequestration

  • Abnormal Lung Tissue
    • Supplied by an Anomalous Systemic Artery (Aorta Most Common)
      • Not Connected to Pulmonary Blood Supply
      • Pathognomonic Feature on Prenatal US
    • Usually No Communication to Tracheo-Bronchial Tree
    • Most Common on Left
  • Types:
    • Intralobar
      • Within Visceral Pleura of Native Lung
      • More Likely to Have Pulmonary Venous Drainage
    • Extralobar
      • Enveloped in Separate Pleural Lining
      • More Likely to Have Systemic Venous Drainage
      • May Be in Chest, Diaphragm or Sub-Diaphragm Locations
      • Associated with Other Anomalies:
        • Congenital Heart Disease
        • Congenital Diaphragmatic Hernia
        • Vertebrae Abnormalities

Congenital Lobar Emphysema/Overinflation

  • Air is Inspired but Limited on Expiration Causing Lobar Hyperinflation
    • Air Trapping Seen on Expiration
  • Most Common Cause: Dysplastic Bronchial Cartilage Creating a “Ball-Valve” Mechanism
  • Most Common Site: Left Upper Lobe
  • Positive-Pressure Ventilation Can Rapidly Amplify Air Trapping
    • Leads to Hemodynamic Instability (Similar to Tension Pneumothorax)
  • Hyperinflated Lobe Characteristically “Pops Out” Upon Thoracotomy Incision

Diagnosis

  • Often Found on Prenatal US – Many Will Regress Throughout Gestation
  • Diagnostic Imaging: CTA or MRA
    • Gold Standard: Pulmonary Angiography

Treatment

  • Primary Tx: Resection/Lobectomy
  • Timing:
    • Respiratory Compromise: Emergent
      • May Require ECMO
    • Asymptomatic: Elective Resection by 1-12 Months
      • Due to Risk of Infection or Malignancy

CPAM on US 1

Pulmonary Sequestration 2

Pulmonary Sequestration on Fetal US – Anomalous Systemic Artery from the Aorta 3

Congenital Lobar Emphysema – CT and Intraoperative Excision 4

Pleuropulmonary Blastoma (PPB)

Basics

  • Most Common Primary Lung Tumor in Peds
  • May Arise in Lung, Pleura, Diaphragm or Mediastinum
  • May Be Solid or Cystic
  • Most Common in Peds Age < 4-6 Years

Associations

  • Commonly Associated with Pleural Effusion & Pneumothorax
  • Associated with DICER1 Mutations
    • Include: PPBs, Cystic Nephroma, Pineal Tumors, Pituitary Blastomas, Thyroid Cancers, Ovarian Tumors & Embryonal Rhabdomyosarcomas
    • Often See Associated Malignancy in Family Members

Types

  • Type 1: Purely Cystic – Best Prognosis
  • Type 2: Mixed Cystic & Solid
  • Type 3: Purely Solid

Prognosis

  • Aggressive Tumor with Overall Poor Prognosis
  • Long-Term Survival:
    • Type I: 80%
    • Type II-III: 42-49%
  • Most Common Site of Mets: Brain

Diagnosis

  • No Characteristic Findings on Imaging
  • Should Be Considered in Differential Diagnosis of Any Benign Cystic Lung Lesion
  • Often Diagnosed at Time of Resection

Treatment

  • Primary Tx: Surgical Resection & Chemo-XRT

Pleuropulmonary Blastoma 5

Pleuropulmonary Blastoma on CT 5

References

  1. Mme Mim. Wikimedia Commons. (License: CC BY-SA-4.0)
  2. Rosen Y. Wikimedia Commons. (License: CC BY-SA-2.0)
  3. Houda el M, Ahmed Z, Amine K, Amina BS, Raja F, Chiraz H. Antenatal diagnosis of extralobar pulmonar sequestration. Pan Afr Med J. 2014 Sep 23;19:54. (License: CC BY-2.0)
  4. Barman S, Mandal KC, Kumar R, Biswas SK, Mukhopadhyay M, Mukhopadhyay B. Congenital cystic lesions of lung in the paediatric population: A 5-year single institutional study with review of literature. Afr J Paediatr Surg. 2015 Jan-Mar;12(1):66-70. (License: CC BY-NC-SA-3.0)
  5. Khan AA, El-Borai AK, Alnoaiji M. Pleuropulmonary blastoma: a case report and review of the literature. Case Rep Pathol. 2014;2014:509086. (License: CC BY-3.0)