Congenital Pulmonary Airway Malformation Manifesting as a Massive Tumor in an Adult Patient

A 52-year-old male patient presented to our hospital (Osaka International Medical and Science Center, Osaka, Japan) with an abnormally large shadow in the right lung lobe. An enhanced computed tomographic scan of the chest revealed a massive tumor with multiple clusters and niveau formation in the lower lobe of the right lung. He received a diagnosis of congenital pulmonary airway malformation with infection and subsequently underwent surgery. Nowadays, most congenital lung malformations are diagnosed during the early intrauterine period, thus making congenital pulmonary airway malformation in adult patients extremely rare. These patients may experience recurrent infections or have malignant tumors; therefore, surgical treatment should be considered regardless of the presence or absence of symptoms.