Congenital Lung Lesions (CPAM)

Natural history and prenatal management. 6–40% of prenatally diagnosed lesions regress and may appear to disappear, though chest X-ray or ultrasound are inadequate to confirm absence [e307-c1, e307-c5]. CVR >1.6 predicts hydrops risk; CVR >2 carries extremely poor prognosis [e307-c3, e1027-c6]. Steroids (betamethasone) dramatically reduce hydrops in microcystic CPAM, achieving ~100% survival when given prophylactically for CVR >1.6 but only 49% once hydrops is established [e1027-c7, e1027-c9, e1027-c37, e1027-c38]. Open fetal surgery is now extremely rare (<1 case/5 years at major centers); thoracoamniotic shunts for macrocystic lesions achieve 70–75% survival [e1027-c8, e1027-c12]. Postnatal timing and technique. 20–40% of untreated lesions develop significant infection; malignancy incidence exceeds 1% [e307-c6, e307-c7]. Surgery is technically easier in smaller infants: vessels are smaller, anatomy is fresh, and inflammation is minimal [e307-c8, e307-c10, e419-c16, e419-c17]. Waiting beyond 3–4 months produces significant fissural inflammation that complicates dissection [e307-c9, e420-c13, e420-c14]. Thoracoscopic lobectomy is feasible in infants >2 kg; median age at high-volume centers is 8–10 weeks [e419-c22, e4911-c13, e4911-c14]. Vascular control demands two separate seals 4–5 mm apart; never take the pulmonary vein trunk near the pericardium—device failure causes fatal retraction [e307-c14, e4463-c27]. Hybrid lesions (CPAM + sequestration) are common on pathology and may harbor large systemic vessels [e307-c4, e420-c21, e420-c26]. Malignancy risk and observation. Pleuropulmonary blastoma (PPB) is radiologically indistinguishable from CPAM until stage 2–3; ~4% of cystic lesions prove to be PPB [e883-c1, e883-c3]. Prenatally diagnosed lesions carry near-zero PPB risk; postnatally diagnosed lesions carry ~10% malignancy risk [e5319-c9, e5319-c10, e6996-c4, e6996-c5]. DICER1 mutation, bilateral disease, and multi-lobar involvement raise PPB suspicion; feeding vessels and prenatal diagnosis lower it [e4463-c19, e4463-c20]. Bronchioalveolar carcinoma risk is ~1%, occurring in teenage years . Extralobar sequestrations without airway communication have minimal infection and near-zero malignancy risk; observation is reasonable [e883-c6, e883-c7, e883-c8].