CCAM (congenital Cystic Adenomatoid Malformation)

For patients & families
CCAM (Congenital Cystic Adenomatoid Malformation) is a lung abnormality that doctors now usually find before birth through ultrasound [e884-c7, e1088-c22]. Most of these lung lesions do not need any treatment before the baby is born, and very few need immediate attention at delivery [e884-c8, e1088-c23]. Many large lesions that look worrisome on prenatal scans can actually shrink during pregnancy or cause no problems after birth [e884-c11, e1088-c27]. However, true CCAMs don't completely disappear—they may get smaller but remain visible on CT scans after birth [e884-c13, e1088-c29]. Doctors estimate that if a CCAM is left alone, there's about a 20-30% chance it could become infected during the child's lifetime . There's also a very small risk (about 1%) of a type of lung cancer developing in the teenage years or early adulthood [e418-c4, e883-c4]. A rare concern is that about 4% of cystic lung lesions that look like CCAM might actually be a different tumor called pleuropulmonary blastoma, which can't be told apart on scans [e418-c3, e883-c3]. Because of these risks, many surgeons recommend removing the affected part of the lung, though some families choose careful monitoring instead after discussing all the risks and benefits with their surgical team [e883-c38, e883-c39].