An extremely rare case of congenital pulmonary airway malformation (CPAM) and atypical adenomatous hyperplasia (AAH) with EGFR mutation in a five-year-old girl

BACKGROUND: Congenital pulmonary airway malformation (CPAM) is the most common congenital lung disorder. Atypical adenomatous hyperplasia (AAH) is a recognized precursor of lung adenocarcinoma. The co-occurrence of CPAM and AAH is exceedingly rare in pediatric patients. CASE PRESENTATION: We present a case of a five-year-old girl who had multiple cystic lesions in the left upper lobe and successfully underwent video-assisted thoracoscopic surgery (VATS). Histologically, the cystic lesions exhibited the typical characteristics of CPAM type 1, and an area of AAH measuring approximately 2 mm was incidentally identified. Next-generation sequencing (NGS) identified the EGFR exon 20 insertion (ex20ins) mutation. The patient remained well 13 months after resection and did not require additional treatment. CONCLUSIONS: We report an extremely rare case of CPAM and AAH with EGFR mutation in a child. The oncogenic driver mutation EGFR may play a potential role in early lung adenocarcinogenesis in pediatric patients. Further studies with a larger number of cases and longer follow-up are required.