Purpose or Case Report: Congenital lung lesions continue to be diagnosed prenatally with increasing frequency. While the etiologies frequently encountered have been well described, there are contradictions in the literature about the prevalence of pathologies. Additionally, no gender or lobar predilection has been confidently reported. The goal of this study was to delineate the epidemiology of congenital lung lesions and their mimickers at our institution to provide comparison to published data.
Methods & Materials: A retrospective review of all patients with a prenatally diagnosed lung lesion who were referred to our surgical center between January 2010 and July 2016 was performed. All patients with postnatal CT imaging and/or surgical excision were included. Patients were divided into categories based on diagnosis, with the pathologic diagnosis considered the gold-standard when available. Lesions were also tabulated with regard to patient gender and location.
Results: 112 patients with a suspected congenital lung lesion were seen at our institution during the study window, and 103 met the inclusion criteria. The most common diagnoses in order of prevalence were congenital pulmonary airway malformation (CPAM) (41.1%), bronchopulmonary sequestration (BPS)/hybrid lesion (22.3%) and overinflation anomalies (15.2%). Additional pathologies encountered were other congenital lung lesions, such as bronchogenic cysts, as well as mimickers including congenital diaphragmatic hernia, pulmonary aplasia and peribronchial myofibroblastic tumor.

With respect to CPAM, 61.4% were found in female patients, lesions were most frequently seen in the left lower lobe (22.7%), and 50% were Type 2 lesions by Stocker classification. Regarding lesions with systemic arterial supply, 76% were hybrid lesions with 100% of the CPAM in hybrid lesions being Stocker Type 2. 58.9% of hybrid lesions were found in males with the same percentage located in the right lower lobe. 52.9% of hybrid lesions were intralobar. The majority of overinflation anomalies were present in females (58.8%), and 64.7% of these anomalies were classified as bronchial atresia based on imaging.
Conclusions: The classification and demographics of congenital lung lesions is controversial and is continually evolving. However, much of the cited statistics are based on studies performed with a small sample size or prior to advanced fetal imaging. This data provides an updated contribution to the epidemiology of congenital lung lesions and their mimickers and offers postnatal outcomes.