Rare presentation of congenital cystic adenomatoid malformation type II detected in adulthood - a case report.

Congenital cystic adenomatoid malformation (CCAM) is a very rare innate pulmonary disorder characterized by the formation of cysts and abnormal dilatation of the respiratory bronchioles. The etiology of the disease remains unknown. CCAM is most commonly diagnosed prenatally or during the neonatal period, and diagnosis in adulthood is extremely rare. The condition is classified into subtypes based on the morphology of the cysts and the extent of pulmonary parenchymal involvement. Clinical symptoms are nonspecific. The aim of this study is to present a case of CCAM type II diagnosed de novo in an adult. A 43-year-old patient was admitted to the clinic due to an abnormal finding on a chest X-ray. A large conglomerate of lesions was located in the inferior lobe of the left lung, and the patient had a history of recurrent pneumonia. After initial diagnostic tests and confirmation of the lesion's location on chest computed tomography, the patient was qualified for surgical intervention. The lesion was removed via video-assisted thoracoscopic surgery, and histopathological examination confirmed the diagnosis of CCAM type II. At the six-month follow-up visit, no recurrence was detected, and treatment was completed. Although it is extremely rare, CCAM type II can also occur in adult patients. This condition should be considered in the differential diagnosis, and such patients should be monitored for potential malignant pulmonary transformation.