Malignancy of congenital cystic adenomatoid malformation of lung in aged.

Congenital cystic adenomatoid malformation is rare in adults, and often asymptomatic. We describe a case of malignant degeneration of a congenital cystic adenomatoid malformation in a 77-year-old man. Congenital cystic adenomatoid malformation must be considered a premalignant lesion, even in older patients. Rigorous preoperative staging must be undertaken. Anatomic resection with extensive lymphadenectomy remains the treatment of choice.