Congenital cystic adenomatoid malformation with associated mucinous bronchioloalveolar carcinoma in a neonate.

Congenital cystic adenomatoid malformation (CCAM) of lung is a rare hamartomatous disorder characterized by abnormal branching morphogenesis of the lung. We report an unusual case of a 2-day-old male newborn with a pulmonary cystic lesion and lobectomy revealed a CCAM of the lung that has overlapping features of type 1 and type 2, complicating with multifocal mucinous bronchioloalveolar carcinoma (BAC). The case indicates that malignant transformation can occur in very early stage of the infancy in the patients with CCAM of lung.