Congenital pulmonary airway malformations (CPAM)
Dr. Abdolohamid jafari nodushan,MD Assistant professor, pediatric pulmonologist,Department of pediatrics, Shahid Sadoughi University of medical science, yazd,iran
ongenital pulmonary airway malformations (CPAM) are multicystic masses of segmental lung tissue with abnormal bronchial proliferation. CPAMs are considered part of the spectrum of bronchopulmonary foregut malformations.
Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic adenomatoid malformation (CCAM), is a developmental anomaly of the respiratory tract.
CPAMs are categorized as types 0 through 4, which are defined pathologically and have different clinical presentations and prognoses.
- Type 1 CPAMs comprise approximately 70 percent of all CPAMs. Large cysts may be detected on prenatal ultrasound and may cause respiratory distress in the neonate. Smaller cysts may present months or years later as incidental findings on imaging studies or as a focus of recurrent pulmonary infection. Type 1 CPAMs are associated with a slight risk of malignancy. Care must be taken not to misclassify type 4 lesions as type 1, because type 4 lesions have a high malignant potential.
•Type 4 CPAMs comprise 5 to 10 percent of all CPAMs. Many of these lesions are cystic forms of pleuropulmonary blastoma (PPB), so identification and resection of these lesions is essential. Important clues that suggest this type of CPAM are presentation with pneumothorax, the presence of bilateral or multifocal lung cysts, or a family history of lung cysts or PPB-associated conditions .
General imaging differential considerations include:
- bronchogenic cyst
- pulmonary sequestration
- systemic arterial supply
- hybrid lesions may present with both CPAM and sequestration features
- congenital diaphragmatic herniation
- congenital lobar emphysema(congenital lobar overinflation)
- hyperlucent and hyperinflated lung segment
- no cystic or solid components
- localized congenital cystic bronchiectasis
- All infants with a prenatal diagnosis of CPAM should have a chest radiograph in the neonatal period, even if they are asymptomatic and even if the lesion appeared to resolve on serial prenatal ultrasounds. In addition, all infants should have computerized tomography (CT) or magnetic resonance imaging (MRI). The timing of the imaging depends on symptoms and on the results of the initial chest radiograph .CT or MRI should be performed even in infants with normal chest radiographs because plain radiographs often fail to detect CPAM in asymptomatic neonates.
- In patients with CPAM that is causing any respiratory symptoms (respiratory distress or tachypnea), we recommend surgical resection rather than observation (Grade 1A). All resected cysts should be carefully examined for evidence of malignancy.
- Asymptomatic infants with a prenatal diagnosis of CPAM should be evaluated with a chest radiograph in the neonatal period. Subsequent management depends on whether there are characteristics that suggest a high risk of complications ;
- For infants and children with high-risk characteristics (large lesions on chest radiograph, bilateral or multifocal cysts, a family history of pleuropulmonary blastoma-associated condition, or pneumothorax), we suggest early surgical resection rather than observation (Grade 2C). These infants should be evaluated with CT or MRI prior to surgery to confirm the diagnosis and further evaluate the lesion. •For infants and children with small lesions and none of the other high-risk features outlined above, either elective surgical resection or conservative management with observation are reasonable options. If surgical resection is chosen for such patients, it is usually performed after the neonatal period but before 12 months of age. If observation is chosen, we suggest close clinical follow-up during the first year of life to monitor for the development of symptoms of respiratory distress or infection, as well as imaging with CT or MRI by six months of age and annually thereafter.
- For infants who are asymptomatic at birth, the risk of developing infection is not well delineated. It is clear that some of these infants will develop infection during the first few years of life if surgery is not performed, but the estimates of the risk for infection ranges from 3 to 30 percent.
- For the majority of infants with CPAM, surgical excision in the neonatal period is curative and the prognosis excellent