The role of thoracic ultrasound in a rare combination of lung abscess and congenital pulmonary airway malformation (CPAM): case report and brief review.

BACKGROUND: Congenital Pulmonary Airway Malformation (CPAM) is a rare lung anomaly in pediatric patients, often diagnosed prenatally or postnatally. Although typically asymptomatic, CPAM can present with severe complications such as recurrent infections or lung abscesses. Thoracic ultrasound (LUS) is emerging as a valuable diagnostic tool, offering a non-invasive and radiation-free alternative to traditional imaging. CASE PRESENTATION: We present the case of a 2-year-old girl with persistent fever, cervical lymphadenopathy, and elevated inflammatory markers, initially raising suspicion for incomplete Kawasaki disease (KD). Despite the administration of intravenous immunoglobulin (IVIG), the fever persisted, prompting further investigations. Lung ultrasound revealed a 5.5 cm lesion with hyperechoic spots and vascularization, suggestive of a lung abscess associated with CPAM. Diagnosis was confirmed by chest CT, and the patient was successfully treated with targeted antibiotic therapy. CONCLUSIONS: This case highlights the importance of considering CPAM as a differential diagnosis in pediatric patients with persistent fever of unknown origin. It also underscores the potential of lung ultrasound as a non-invasive diagnostic tool, complementing traditional imaging methods, in the management of complex pediatric conditions.