PEDBASE.org - The Pediatric Database - Detailed information of BRONCHOGENIC CYSTS

BRONCHOGENIC CYSTS

DEFINITION:

A congenital anomaly of the lung characterized by a unilobular cystic lesion and subsequent respiratory manifestations.

EPIDEMIOLOGY:

incidence: rare
age of onset:
- newborn -> childhood (depends on location, size, and symptoms)
risk factors:
- sporadic
- M = F

PATHOGENESIS:

1. Background

abnormal budding of the ventral diverticulum of the foregut during the 5th week of gestation producing two types of broncho-genic cysts:

1. Intrapulmonary (15%)

often communicate with the bronchial tree
2/3rd's are aerated, 1/3rd filled with clear or mucoid material
lack own blood supply
distal structures remain undeveloped, i.e., alveoli
lined with ciliated columnar respiratory epithelium

2. Mediastinal (85%)

usually do not communicate with the bronchial tree but connected by a stalk or a common wall
most situated near the carina
usually filled with a clear water-like liquid or a viscous gelatinous material
lined with ciliated columnar respiratory epithelium

CLINICAL FEATURES:

1. Respiratory Manifestations

1. Asymptomatic

found on routine chest x-ray

2. Symptomatic

when cyst causes airway obstruction:
- wheezing, stridor, cyanosis
- chronic cough
- mild -> severe respiratory distress
- substernal discomfort

3. Complications

hemoptysis
recurrent lung infections +/- purulent sputum
rhabdomyosarcoma (arising from the cyst wall)

INVESTIGATIONS:

1. Imaging Studies

1. Chest X-Ray/CT/MRI

1. Intrapulmonary Cysts

round or oval fluid- or air-filled cyst
wide range of sizes
usually unilocular and 2/3rds located in lower lobes
may see an air-fluid level in cyst

2. Mediastinal Cysts

round or oval homogeneous mass
wide range of sizes and often extends slightly to the right
usually unilocular

3. Complications

pneumonia +/- atelectasis
emphysema

2. Esophagram

to detect an esophageal deviation due to a subcarinal mediastinal cyst

3. Bronchoscopy

to detect intrapulmonary cysts

MANAGEMENT:

1. Supportive

if respiratory distress
antibiotic therapy for recurrent lung infections

2. Surgery

indicated for significant respiratory distress and/or recurrent lung infections

3. Prognosis

excellent

Pediatric Database - BRONCHOGENIC CYSTS

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