title: Postnatal spontaneous resolution of congenital cystic adenomatoid malformations.
abstract: OBJECTIVE
  Although antenatal resolution of congenital cystic adenomatoid malformations (CCAMs) is well documented, complete spontaneous postnatal resolution is rare, its existence even questioned by some.
  
  
  METHODS
  All cases of antenatally diagnosed CCAMs over 7 years were retrospectively reviewed. Inclusion criteria were the following: (1) antenatal diagnosis of CCAM, (2) persistence on postnatal imaging, and (3) subsequent spontaneous resolution on postnatal imaging.
  
  
  RESULTS
  Of 56 antenatally diagnosed CCAMs, 2 patients were identified. Both had macrocystic lesions. In case 1, the CCAM that filled the hemithorax on antenatal ultrasound was smaller on postnatal chest radiograph and disappeared by age 37 months on computed tomography. Case 2 had significant reduction of the CCAM at birth (persistence of the lesion on initial radiographs and ultrasound was documented). By 5 months, the lesion was not evident on computed tomography. Neither case was associated with symptoms, polyhydramnios, hydrops, or other abnormalities.
  
  
  CONCLUSIONS
  In patients with an antenatal diagnosis of CCAM, spontaneous resolution may occur postnatally in 4% of cases. Significant reduction in CCAM size may portend possible disappearance and therefore warrants an observational period before resection.
authors.affiliation: Department of Pediatric Surgery, British Columbia Children's Hospital, Vancouver, BC, Canada V6H 3V4.
authors.forename: Sonia A
authors.initials: SA
authors.lastname: Butterworth
authors.forename: Geoffrey K
authors.initials: GK
authors.lastname: Blair
mesh_terms: D000367:Age Factors; D015615:Cystic Adenomatoid Malformation of Lung, Congenital / Q000000981:diagnostic imaging / Q000196:embryology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012075:Remission, Spontaneous; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016216:Ultrasonography, Prenatal