SHM Converge Scientific Abstract ePoster Gallery-Incidental Adult Congenital Pulmonary Airway Malformation Mimicking Unilateral Bullous Emphysema in a Never-Smoker

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This case describes a 39-year-old never-smoking woman with obesity, PTSD, anxiety, and two years of progressive exertional dyspnea who was found incidentally after a motor vehicle accident to have multiple large right lung cystic/bullous lesions on chest CT. Her symptoms had previously been attributed to deconditioning, obesity, and mild sleep apnea, illustrating how common comorbidities can obscure a rare pulmonary diagnosis.<br /><br />Pulmonary function testing showed mild airflow obstruction with marked air trapping but preserved diffusion capacity. Because imaging suggested large bullae and could not exclude pleuropulmonary blastoma or malignant change, surgery was recommended both to reduce pneumothorax risk and for definitive diagnosis. She underwent right lower lobectomy and right upper lobe wedge resection.<br /><br />Histopathology demonstrated multilocular respiratory epithelium-lined cysts with ciliated columnar epithelium, smooth muscle, and focal fibrosis, confirming congenital pulmonary airway malformation (CPAM) type 1. CPAM is a rare developmental lung anomaly usually diagnosed in utero or childhood, and adult presentation is uncommon. In adults, it can closely mimic unilateral bullous emphysema or other cystic lung diseases on imaging, making diagnosis difficult without pathology.<br /><br />The patient recovered well and remained clinically stable on budesonide-formoterol, nasal steroids, weight-loss therapy, and pulmonary rehabilitation.<br /><br />The key lesson is that adult CPAM should remain in the differential diagnosis for unilateral cystic lung lesions, especially when imaging is atypical or symptoms are unexplained. The case also highlights the important role of internists in managing incidental findings, coordinating multidisciplinary evaluation, and guiding patients through uncertain diagnostic and surgical decisions.

Asset Subtitle

Long Huen Au

Meta Tag

Author List Ahmadreza Ghasemiesfe, Linh N. Vo, Long Huen Au, Shotaro Naganawa, Viharkumar Patel

Category Clinical Vignettes

Concept Congenital Pulmonary Airway Malformation

Concept Unilateral Cystic Lung Lesion

Concept Differential Diagnosis

Concept Adult

Concept Imaging

Distinguished Non-Finalist

Presenter Organization University of California, Davis School of Medicine

Presenting Author Long Huen Au

Track Adult

Keywords

congenital pulmonary airway malformation

CPAM type 1

adult lung cystic lesion

unilateral bullous emphysema

pulmonary cysts

lobectomy

air trapping

exertional dyspnea

histopathology

incidental chest CT

Congenital Pulmonary Airway Malformation

Unilateral Cystic Lung Lesion

Differential Diagnosis

Adult

Imaging