eMedicine Specialties > Pediatrics: General Medicine > Pulmonology

Cystic Adenomatoid Malformation

Author: Anne E Stone, MD, Fellow, Division of Pediatric Pulmonary Medicine, Columbia University Medical Center, Children's Hospital of New York-Presbyterian
Coauthor(s): Michael R Bye, MD, Attending Physician, Pediatric Pulmonary Medicine, Columbia University Medical Center; Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons; David J Vaughan, MBBCh, Consultant Pediatrician, Department of Pediatrics, Our Lady of Lourdes Hospital, Ireland; Jerry Zimmerman, MD, PhD, Professor, Department of Pediatrics/Anesthesia, University of Washington School of Medicine; Director, Division of Pediatric Critical Care Medicine, Children's Hospital of Seattle
Contributor Information and Disclosures

Updated: Aug 1, 2008

Introduction

Background

Congenital cystic adenomatoid malformation (CCAM) is a rare abnormality of lung development. CCAM is a cystic area within the lung that stems from abnormal embryogenesis. An adenomatous overgrowth of the terminal bronchioles with a consequent reduction in alveolar growth occurs.1

The routine use of prenatal ultrasonography has led to frequent prenatal diagnosis and has provided great insight into the natural history of CCAM. Improvements in surgical techniques (ie, both prenatal and postnatal) as well as greatly enhanced imaging modalities have altered the surgical approach to this lesion.

Pathophysiology

The pathophysiologic effects of CCAM may be divided into prenatal and postnatal effects. Large lesions may be associated with the development of hydrops fetalis in as many as 40% cases and is a poor prognostic sign. Hydrops is thought to arise from compression of the inferior vena cava, which compromises venous return and leads to a decrease in cardiac output and the development of effusions. Fetal demise may result; premature delivery is attempted in order to salvage the fetus.2 The other main prenatal event is compromised pulmonary growth. Resultant pulmonary hypoplasia may lead to the postnatal development of respiratory distress.

Polyhydramnios has also been associated with CCAM. This develops as a result of elevated intrathoracic pressure that leads to esophageal compression and the inability to swallow.3

CCAM may remain undiagnosed until it is discovered as an incidental finding later in life; however, its usual postnatal presentation is respiratory distress in the newborn period. This may be due to pulmonary hypoplasia, mediastinal shift, spontaneous pneumothorax, and pleural effusions secondary to hydrops. Recurrent chest infections may be a feature later in life.4 A risk of malignant transformation in later years is noted.5

Prenatal regression and complete prenatal resolution have also been described.5,6,7

Frequency

United States

No data are available regarding the frequency of this lesion; however, it is a rare condition.

International

A review of 48 cases from 5 centers in Canada led to an estimated incidence of 1:25,000 to 1:35,000 of patients who were prenatally diagnosed.6 The use of prenatal ultrasonography has led to an increase in prenatal diagnosis.

Mortality/Morbidity

  • Most series report a mortality rate of 25-30% of all children who present in the newborn period with CCAM; however, these figures do not include asymptomatic children who present later in life. Furthermore, the use of elective abortion may lead to an underestimation of perinatal mortality by preferentially terminating fetuses with a higher risk of mortality. The reported mortality rate of prenatally diagnosed CCAMs ranges from 9-49%.
  • Risk factors for a poor outcome include hydrops fetalis.2,6 Other indicators of poor prognosis include the type of lesion; microcystic CCAM is associated with much poorer outcomes.6,8
  • The overall size of the lesion has also been reported as being an important predictor of survival;9,10 however, this index may be compromised by the fact that CCAM may decrease in size or even resolve over time in utero.6 The major morbidity is related to pulmonary compromise. A large lesion may be associated with pulmonary hypoplasia. This can cause respiratory distress at birth.
  • Some authorities have suggested that the presence of bilateral lesions is associated with a worse outcome. More controversially, left-sided lesions may be associated with a greater mortality rate than right-sided lesions.
  • One study suggested that polyhydramnios is also associated with a poorer outcome.
  • The potential for malignant transformation is recognized in all cases of CCAM.5,11,12 Whether or not complete resection of the affected area completely removes this risk is not known.
  • Other complications that have been described include the development of spontaneous pneumothorax, hemopneumothorax, and associated hemoptysis.6

Age

CCAM is a congenital condition. Cases are typically identified prenatally by routine ultrasonography screening.6 Most postnatally identified cases present in the newborn period. CCAM may present in the older child and adult as an incidental finding or secondary to repeated infection.13,4

Clinical

History

With the increasing use of prenatal ultrasonography as well as improvement in technology and skill, most cases of congenital cystic adenomatoid malformation (CCAM) are prenatally diagnosed. Prenatally diagnosed lesions can present with various symptoms.

  • Respiratory distress13
    • This is the presenting symptom in most newborns with a diagnosis of CCAM. It may range in severity from grunting, tachypnea, and a mild oxygen requirement to fulminant respiratory failure requiring aggressive ventilator support or extracorporeal membrane oxygenation (ECMO).
    • Multiple mechanisms account for the onset of respiratory difficulty. Pulmonary hypoplasia may arise as a consequence of a large CCAM, mediastinal shift may compromise cardiac and respiratory function, spontaneous pneumothoraces may occur, and air trapping within the cyst leads to compression of functional pulmonary tissue.
  • Recurrent infection: Children in whom the CCAM has not been resected are at risk of recurrent pulmonary infections due to bronchial compression, air trapping, and inability to clear secretions.
  • Hemoptysis: Hemoptysis has occasionally been described as a manifestation of CCAM in the older child.
  • Dyspnea and chest pain: Dyspnea may be a feature of pneumothorax, which has been described as a presenting feature of CCAM.
  • Miscellaneous: Cough, fever, and failure to thrive have all been reported in association with the presentation of CCAM.

Physical

Generally, the physical signs observed in children with CCAM are nonspecific.

  • Tachypnea: Tachypnea is the most common sign encountered in the newborn period, reflecting respiratory distress.
  • Pneumothorax/air trapping: Signs consistent with a pneumothorax or air trapping may be elicited, including tracheal deviation, which indicates mediastinal shift, shifted heart sounds, and decreased air entry on the affected side.
  • Cyanosis
  • Accessory muscle use
  • Grunting
  • Failure to thrive

Causes

The cause of CCAM is not understood.

  • Resected CCAMs show signs of increased cell proliferation and decreased apoptosis.1,14
  • Studies have investigated the role of HOXB5 gene and protein expression, as well as other growth factors such as mesenchymal platelet–derived growth factor-BB.15,16

More on Cystic Adenomatoid Malformation

Overview: Cystic Adenomatoid Malformation
Differential Diagnoses & Workup: Cystic Adenomatoid Malformation
Treatment & Medication: Cystic Adenomatoid Malformation
Follow-up: Cystic Adenomatoid Malformation
Multimedia: Cystic Adenomatoid Malformation
References
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References

  1. Wilson RD, Hedrick HL, Liechty KW, et al. Cystic adenomatoid malformation of the lung: review of genetics, prenatal diagnosis, and in utero treatment. Am J Med Genet A. Jan 15 2006;140(2):151-5. [Medline].

  2. Adzick NS, Harrison MR, Crombleholme TM, et al. Fetal lung lesions: management and outcome. Am J Obstet Gynecol. Oct 1998;179(4):884-9. [Medline].

  3. Adzick NS. Management of fetal lung lesions. Clin Perinatol. Sep 2003;30(3):481-92. [Medline].

  4. Luján M, Bosque M, Mirapeix RM, Marco MT, Asensio O, Domingo C. Late-onset congenital cystic adenomatoid malformation of the lung. Embryology, clinical symptomatology, diagnostic procedures, therapeutic approach and clinical follow-up. Respiration. 2002;69(2):148-54. [Medline].

  5. Sauvat F, Michel JL, Benachi A, Emond S, Revillon Y. Management of asymptomatic neonatal cystic adenomatoid malformations. J Pediatr Surg. Apr 2003;38(4):548-52. [Medline].

  6. Laberge JM, Flageole H, Pugash D, et al. Outcome of the prenatally diagnosed congenital cystic adenomatoid lung malformation: a Canadian experience. Fetal Diagn Ther. May-Jun 2001;16(3):178-86. [Medline].

  7. Duncombe GJ, Dickinson JE, Kikiros CS. Prenatal diagnosis and management of congenital cystic adenomatoid malformation of the lung. Am J Obstet Gynecol. Oct 2002;187(4):950-4. [Medline].

  8. Stocker JT, Madewell JE, Drake RM. Congenital cystic adenomatoid malformation of the lung. Classification and morphologic spectrum. Hum Pathol. Mar 1977;8(2):155-71. [Medline].

  9. Usui N, Kamata S, Sawai T, et al. Outcome predictors for infants with cystic lung disease. J Pediatr Surg. Apr 2004;39(4):603-6. [Medline].

  10. Crombleholme TM, Coleman B, Hedrick H, et al. Cystic adenomatoid malformation volume ratio predicts outcome in prenatally diagnosed cystic adenomatoid malformation of the lung. J Pediatr Surg. Mar 2002;37(3):331-8. [Medline].

  11. Murphy JJ, Blair GK, Fraser GC, et al. Rhabdomyosarcoma arising within congenital pulmonary cysts: report of three cases. J Pediatr Surg. Oct 1992;27(10):1364-7. [Medline].

  12. Granata C, Gambini C, Balducci T, Toma P, Michelazzi A, Conte M. Bronchioloalveolar carcinoma arising in congenital cystic adenomatoid malformation in a child: a case report and review on malignancies originating in congenital cystic adenomatoid malformation. Pediatr Pulmonol. Jan 1998;25(1):62-6. [Medline].

  13. Parikh D, Samuel M. Congenital cystic lung lesions: is surgical resection essential?. Pediatr Pulmonol. Dec 2005;40(6):533-7. [Medline].

  14. Cass DL, Quinn TM, Yang EY, Liechty KW, Crombleholme TM, Flake AW. Increased cell proliferation and decreased apoptosis characterize congenital cystic adenomatoid malformation of the lung. J Pediatr Surg. Jul 1998;33(7):1043-6; discussion 1047. [Medline].

  15. Liechty KW, Crombleholme TM, Quinn TM, Cass DL, Flake AW, Adzick NS. Elevated platelet-derived growth factor-B in congenital cystic adenomatoid malformations requiring fetal resection. J Pediatr Surg. May 1999;34(5):805-9; discussion 809-10. [Medline].

  16. Volpe MV, Pham L, Lessin M, et al. Expression of Hoxb-5 during human lung development and in congenital lung malformations. Birth Defects Res A Clin Mol Teratol. Aug 2003;67(8):550-6. [Medline].

  17. Schwartz DS, Reyes-Mugica M, Keller MS. Imaging of surgical diseases of the newborn chest. Intrapleural mass lesions. Radiol Clin North Am. Nov 1999;37(6):1067-78, v. [Medline].

  18. Hernanz-Schulman M. Cysts and cystlike lesions of the lung. Radiol Clin North Am. May 1993;31(3):631-49. [Medline].

  19. Kim WS, Lee KS, Kim IO, et al. Congenital cystic adenomatoid malformation of the lung: CT-pathologic correlation. AJR Am J Roentgenol. Jan 1997;168(1):47-53. [Medline].

  20. Adzick NS, Harrison MR. Management of the fetus with a cystic adenomatoid malformation. World J Surg. May-Jun 1993;17(3):342-9. [Medline].

  21. Hubbard AM, Harty P. Prenatal magnetic resonance imaging of fetal anomalies. Semin Roentgenol. Jan 1999;34(1):41-7. [Medline].

  22. Hubbard AM, Harty MP, States LJ. A new tool for prenatal diagnosis: ultrafast fetal MRI. Semin Perinatol. Dec 1999;23(6):437-47. [Medline].

  23. Frenckner B, Freyschuss U. Pulmonary function after lobectomy for congenital lobar emphysema and congenital cystic adenomatoid malformation. A follow-up study. Scand J Thorac Cardiovasc Surg. 1982;16(3):293-8. [Medline].

  24. Kamata S, Ishikawa S, Usui N, et al. Clinical significance of the lung/thorax transverse-area ratio in fetuses with cystic lung disease. Pediatr Surg Int. 1999;15(7):470-4. [Medline].

  25. Asabe K, Oka Y, Shirakusa T. Fetal case of congenital cystic adenomatoid malformation of the lung: fetal therapy and a review of the published reports in Japan. Congenit Anom (Kyoto). Sep 2005;45(3):96-101. [Medline].

  26. Bunduki V, Ruano R, da Silva MM, et al. Prognostic factors associated with congenital cystic adenomatoid malformation of the lung. Prenat Diagn. Jun 2000;20(6):459-64. [Medline].

  27. Calvert JK, Boyd PA, Chamberlain PC, Syed S, Lakhoo K. Outcome of antenatally suspected congenital cystic adenomatoid malformation of the lung: 10 years' experience 1991-2001. Arch Dis Child Fetal Neonatal Ed. Jan 2006;91(1):F26-8. [Medline].

  28. Cloutier MM, Schaeffer DA, Hight D. Congenital cystic adenomatoid malformation. Chest. Mar 1993;103(3):761-4. [Medline].

  29. Ierullo AM, Ganapathy R, Crowley S, et al. Neonatal outcome of antenatally diagnosed congenital cystic adenomatoid malformations. Ultrasound Obstet Gynecol. Aug 2005;26(2):150-3. [Medline].

  30. Ioachimescu OC, Mehta AC. From cystic pulmonary airway malformation, to bronchioloalveolar carcinoma and adenocarcinoma of the lung. Eur Respir J. Dec 2005;26(6):1181-7. [Medline].

  31. Jona JZ. Advances in fetal surgery. Pediatr Clin North Am. Jun 1998;45(3):599-604. [Medline].

  32. Kitano Y, Flake AW, Crombleholme TM, et al. Open fetal surgery for life-threatening fetal malformations. Semin Perinatol. Dec 1999;23(6):448-61. [Medline].

  33. Kravitz RM. Congenital malformations of the lung. Pediatr Clin North Am. Jun 1994;41(3):453-72. [Medline].

  34. Kulwa E, Tharakan T, Baxi L. Congenital cystic adenomatoid malformation in the fetus: a hypothesis of its development. Fetal Diagn Ther. Sep-Oct 2005;20(5):472-4. [Medline].

  35. Shanmugam G, MacArthur K, Pollock JC. Congenital lung malformations--antenatal and postnatal evaluation and management. Eur J Cardiothorac Surg. Jan 2005;27(1):45-52. [Medline].

  36. Tawil MI, Pilling DW. Congenital cystic adenomatoid malformation: is there a difference between the antenatally and postnatally diagnosed cases?. Pediatr Radiol. Jan 2005;35(1):79-84. [Medline].

  37. Visrutaratna P, Euathrongchit J, Kattipattanapong V. Clinics in diagnostic imaging (86). Ruptured bronchogenic cyst. Singapore Med J. Jun 2003;44(6):325-9. [Medline].

  38. Winters WD, Effmann EL, Nghiem HV, Nyberg DA. Disappearing fetal lung masses: importance of postnatal imaging studies. Pediatr Radiol. Jun 1997;27(6):535-9. [Medline].

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Further Reading

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Keywords

congenital cystic adenomatoid malformation, CCAM, hydrops fetalis, microcystic congenital cystic adenomatoid malformation, microcystic CCAM, macrocystic congenital cystic adenomatoid malformation, macrocystic CCAM, pulmonary hypoplasia, hamartoma, premature delivery, polyhydramnios, respiratory distress, mediastinal shift, spontaneous pneumothorax, recurrent chest infection, pulmonary compromise, hemoptysis, failure to thrive

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Contributor Information and Disclosures

Author

Anne E Stone, MD, Fellow, Division of Pediatric Pulmonary Medicine, Columbia University Medical Center, Children's Hospital of New York-Presbyterian
Anne E Stone, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, and American Thoracic Society
Disclosure: Nothing to disclose.

Coauthor(s)

Michael R Bye, MD, Attending Physician, Pediatric Pulmonary Medicine, Columbia University Medical Center; Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons
Michael R Bye, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, and American Thoracic Society
Disclosure: Merck Honoraria Speaking and teaching

David J Vaughan, MBBCh, Consultant Pediatrician, Department of Pediatrics, Our Lady of Lourdes Hospital, Ireland
David J Vaughan, MBBCh is a member of the following medical societies: American College of Chest Physicians, American Thoracic Society, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Jerry Zimmerman, MD, PhD, Professor, Department of Pediatrics/Anesthesia, University of Washington School of Medicine; Director, Division of Pediatric Critical Care Medicine, Children's Hospital of Seattle
Jerry Zimmerman, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, Society for Pediatric Research, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Medical Editor

Thomas Scanlin, MD, Chief, Division of Pediatric Pulmonary & Cystic Fibrosis, Assistant Professor, Department of Pediatrics, Robert Wood Johnson University Medical Group
Thomas Scanlin, MD is a member of the following medical societies: American Thoracic Society and Society for Pediatric Research
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

Charles Callahan, DO, Professor, Deputy Chief of Clinical Services, Walter Reed Army Medical Center
Charles Callahan, DO is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, American College of Osteopathic Pediatricians, American Thoracic Society, Association of Military Surgeons of the US, and Christian Medical & Dental Society
Disclosure: Nothing to disclose.

CME Editor

Mary E Cataletto, MD, Associate Director, Division of Pediatric Pulmonology, Winthrop University Hospital; Professor of Clinical Pediatrics, State University of New York at Stony Brook; Director of Children's Sleep Services, Winthrop University Hospital
Mary E Cataletto, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Chest Physicians
Disclosure: Shering Plough Pharmaceuticals Honoraria Consulting

Chief Editor

Michael R Bye, MD, Attending Physician, Pediatric Pulmonary Medicine, Columbia University Medical Center; Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons
Michael R Bye, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, and American Thoracic Society
Disclosure: Merck Honoraria Speaking and teaching

 
 
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