Definitive Diagnosis of CPAM in Adults
The definitive diagnosis of Congenital Pulmonary Airway Malformation (CPAM) in adults requires surgical resection with histopathological examination, as imaging alone cannot provide definitive confirmation. 1, 2, 3
Diagnostic Pathway
Initial Imaging: High-Resolution CT Chest
CT imaging is the primary diagnostic modality that identifies characteristic features of CPAM, though it remains presumptive until pathological confirmation. 3, 4, 5
Key CT findings that suggest CPAM include:
- Multiple cystic lesions with well-defined areas of low attenuation in a single lobe (most commonly lower lobes or lingula) 1, 4, 5
- Dedicated pulmonary arterial and venous drainage from the pulmonary circulation (not systemic), which differentiates CPAM from pulmonary sequestration 5
- Ground glass opacities and interlobular septal thickening may be present, particularly with superimposed infection 3
- Unilateral involvement affecting a single lobe in the vast majority of cases 2
Bronchoscopy for Lesion Localization
Bronchoscopy should be performed to localize the lesion and exclude other pathology, particularly when hemoptysis is present. 1 This helps surgical planning but does not provide definitive diagnosis.
Definitive Diagnosis: Surgical Resection with Histopathology
Surgical resection is both diagnostic and therapeutic, and is recommended at the time of diagnosis for symptomatic adults. 2, 3, 4
Surgical approaches include:
- Video-assisted thoracoscopic surgery (VATS) with lobectomy or wedge resection is the preferred approach for most cases 1, 2
- Pneumonectomy may be required in rare cases with extensive involvement of an entire lung 3
Histopathological examination of the resected specimen provides the only definitive diagnosis by confirming the characteristic dysplastic bronchial development and glandular overgrowth, and classifying the CPAM type (0-IV). 3, 4, 5
Critical Pitfalls to Avoid
Do not rely on imaging alone for definitive diagnosis. While CT findings may be highly suggestive, multiple conditions can mimic CPAM including:
- Pulmonary sequestration (differentiated by systemic arterial supply) 5
- Congenital bronchogenic cyst 5
- Congenital lobar emphysema 5
- Pleuropulmonary blastoma 5
- Congenital cystic bronchiectasis 5
Do not delay surgical intervention in symptomatic patients. Adults with CPAM presenting with recurrent infections, hemoptysis, or pneumothorax require surgical resection to prevent:
- Recurrent respiratory tract infections 2, 3, 4
- Life-threatening hemorrhage 1, 2
- Pneumothorax 2, 3
- Malignant transformation (a definitive risk that necessitates resection even in asymptomatic cases) 2, 3
Clinical Presentation Clues in Adults
Adults with CPAM typically present with:
- Recurrent pulmonary infections (most common presentation) 3, 4, 5
- Hemoptysis (frank blood or blood-tinged sputum) 1, 2
- Spontaneous pneumothorax 2, 3
- Pleuritic chest pain 4, 5
- History of frequent lower respiratory tract infections during childhood 3
Post-Surgical Surveillance
Close monitoring is advocated even after surgical resection due to the mild but definitive risk of malignancy. 2 The specific surveillance protocol should include periodic clinical follow-up, though the optimal imaging interval is not well-established in the literature for adults.