Congenital cystic adenomatoid malformation with prenatal diagnosis: case report.
Congenital cystic diseases of the lung and mediastinum include congenital cystic adenomatoid malformation (CCAM), bronchopulmonary "sequestration", congenital lobar emphysema, broncogenic cyst, esophageal duplication cysts and neurogenic cysts (1).
Congenital cystic adenomatoid malformation is an embrionic developmental disorder characterized by cystic enlargement and overgrowth of terminal bronchioles which are surrounded by various epithelial cells. It occurs at the 6-8th gestational week (GW). It is observed with an equal frequency in both lungs and its incidence ranges between 1/10 000 and 1/35 000. The lesions usually tend to involve a single lobe and especially the lower lobe. The incidence of the disease does not vary according to race or gender (2).
Congenital cystic adenomatoid malformation is a rare but life-threatening lung anomaly. Cysts which grow and enlarge can compress the lungs, large vessels and esophagus. As a result of this it can lead to mediastinal shift, hydrops and polyhydramniosis in fetal life and life-threatening respiratory distress in the postnatal period. However, most patients have no complaints at birth and lung graphies taken in the postnatal period are normal (3).
We would like to present a patient with CCAM who was diagnosed in the intrauterine period and underwent thoracoamniotic shunting and who was lost in the first day of life with severe respiratory distress.
Our patient was born at the 25th gestational week according to the last mensturation date by cesarean section with a birth weight of 670 g from the first pregnancy of a 20-year-old mother. He was followed up with the diagnoses of polyhydramniosis and hydrops fetalis in the prenatal period. On ultrasonographic examination (USG) performed at the 24th gestational week, a uniloculated and pure cystic lesion with regular contours and a relatively thick wall including air-fluid level which caused shifting of the middle line and mediastinal structures towards the right side was observed in the left hemithorax. The largest size of the cyst was measured to be 4x3,5x3,8 cm (Picture 1). Hydrops fetalis due to type 1 CCAM was found on ultrasonography. Thoracoamniotic shunt was inserted at the 24th gestational week by the department of obstetrics and gynecology to ameliorate mass compression. The patient was born due to premature rupture of membranes and preterm delivery by urgent cesarean section one week after the procedure. During cesarean section, it was observed that the place of the thoracoamniotic shunt catheter was not good and the catheter floated in the amniotic fluid.
The patient who did not cry immediately at birth and who had APGAR scores of 3 and 5 at the first and 5th minutes was intubated and internalized in the intensive care unit. On lung graphy, a cystic lesion which shifted the mediastinum towards the right side was observed in the left hemithorax and atelectasia was present in the right lung because of compression (Picture 2). On physical examination, the body weight was found to be 670 g (3-10th percentile), the height was found to be 32 cm (3rd percentile), the head circumference was found to be 26 cm (3rd percentile), the respiratory rate was found to be 66/min and the oxygen saturation was found to be 78%. No additional pathologic physical examination finding was observed except for premature delivery. Laboratory tests revealed that complete blood count, electrolytes, renal and hepatic function tests and CRP level were normal. The baseline blood gases were as follows: pH: 7.17, pC[O.sub.2] 78.6 mmHg, p[O.sub.2] 54 mmHg and HC[O.sub.3] 15.1 mmol/L, BE:-7 mmol/L. On thoracal computarized tomography (CT), a cystic lesion with a relatively thick wall including microcysts in the lower part and air-fluid level was observed in the left hemithorax causing shifting of the middle line and mediastinal structures towards the right side. The largest transaxial size of the cyst was measured to be 4.5x3.5x5 cm (Picture 3). Thorasynthesis was performed in the left hemithorax of the patient whose oxygen saturation could not be increased; 5 cc serous fluid and 20 cc air was derived and a thoracic catheter was placed. No change in the cyst's diameter was observed after placing the chest tube. Surgical intervention was planned, but the patient was lost in the first 12 hours because of respiratory distress.
Congenital cystic malformation was classified in three types by Stocker et al. (4) in 1977 based on clinical, macroscopic and microscopic criteria. Type I is the most common type (50-60%) and is composed of one or multiple cysts with a diameter of 2-10 cm. Its wall is layered by multiple pseudo-stratified cylindrical epithelium. Type II occurs with a rate of 30-40% and includes multiple small cysts layered by cuboid cylindrical epithelium with a diameter of 0.5-2 cm. Type III occurs with a rate of 10% and has the worst prognosis.
Sonography is the primary method in evaluation of fetal thorax. The classification made by Stocker et al. (4) according to anatomic and clinical variations can be used as sonographic typing. In our patient, the diagnosis was made by USG findings in the prenatal period and was found to be compatible with type I CCAM (5).
With use of prenatal imaging methods CCAM is diagnosed more frequently. When a mass is found in the lung in fetal life, its localization, size, dimensions and appearance should be carefully examined. The origin of the vascular structure of the mass should be determined by Doppler USG to differentiate it from pulmonary sequestration. Patients who are diagnosed as CCAM by USG in the prenatal period should be followed up closely in terms of development of fetal hydropic changes which indicate fetal mortality. In these patients, problems including polyhydramniosis, lung hypoplasia and mediastinal shift can be determined by USG (2). Hydrops fetalis, lung hypolplasia due to cystic compression, polyhydramniosis and mediastinal shift were found in our patient.
Development of hydrops due to congenital cystic adenomatoid malformation can be predicted in the prenatal period by calculating CCAM volume ratio (CVR) on USG. Cystic volume is found by multiplying the lenght, width and depth of the cyst measured on USG by 0.523 (lenght x width x depth x 0.523). CCAM volume ratio reflects the ratio of the cystic volume to head circumference. When CCAM volume ratio was <1.6, the survival rate and the rate of development of hydrops were found to be 94% and 3%, respectively (6). In our patient, CCAM volume ratio was found to be 1.78 and hydrops fetalis was present. Therefore, CCAM volume ratio appears to be useful in determining the risk of development of hydrops.
In approximately 15% of the patients with congenital adenomatoid malformation, the diameter of the cyst decreases as the gestational age increases and the reason for this is unknown. The cyst reaches its largest size at the 28th gestational week and decreases in size in approximately 20% of the patients after the 29th gestational week (3). Since our patient was born at the 25th gestational week, the prognosis of the cyst could not be followed up.
Mortality depends on the size of the primary lesion. In a study performed in Canada in 48 patients with CCAM, the mortality rate was reported to be 10% (7). 10 of these patients were reported be lost after birth, 8 patients were reported as spontaneous or voluntary abortion and no mortality was reported in 30 patients. It has been observed that large lesions have a higher risk to develop mediastinal shift, vascular failure, polyhydramniosis, hydrops fetalis and lung hypoplasia due to the effect of compression. Type III lesions have a poorer prognosis because of a tendency to become larger. Other factors which affect the prognosis include bilateral lung involvement, premature delivery and accompanying severe malformations. Anomalies are usually associated with type II CCAM. Generally, renal, cardiac, intestinal and skeletal anomalies accompany (7).
The follow-up and diagnosis of fetal CCAM depends on the time of diagnosis, the size of the cyst and presence of findings related to the compression of the cyst. In fetuses in whom CCAM alone is present without fetal hydrops, follow-up with serial USG and term delivery are recommended. If sole CCAM and hydrops fetalis are present, extrauteral "intrapartum" surgical treatment is performed after the 32nd gestational week and thoracoamniotic shunt or open fetal surgery are recommended before the 32nd gestational week. Thoracoamniotic shunt may not be efficient in CCAM with a predominantly solid lesion and open fetal surgery is recommended in this case (8). In our patient, thoracoamniotic shunt was inserted, since the gestational age was younger than the 32nd gestational week, but the shunt was not functional, since the catheter was displaced.
The general rule in the postnatal therapeutic approach in CCAM is as follows: it is reported that surgical procedure may not be needed in patients without complaints. In patients with complaints, surgical treatment is contraversial and close follow-up of these patients is recommended. Cetinkaya et al. (9) reported that the cysts completely disappeared at the 5th month after birth with postnatal traditional treatment in a patient with type I CCAM and emphasized the importance of traditional treatment. Ozdemir et al. (10) emphasized the importance of early surgical treatment in terms of prognosis in a patient with CCAM who was operated on the 12th day because of symptoms (10). Even if CCAM is asymptomatic in the postnatal period, it is reccomended that the masses should be excised completely because of the risk of recurrent infection and development of carcinoma (8).
Our patient who was evaluated as type I CCAM and was expected to have a good prognosis was lost in the first 12 hours. Conclusively, the type of CCAM alone does not indicate prognosis. Secondary pathologies (hydrops fetalis, polyhydramniosis) and CVR should be carefully evaluated in association with the type of CCAM.
(1.) Miller MJ, Fanaroff AA, Martin RJ. Respiratory disorders in preterm and term infants. In: Martin RJ, Fanaroff AA, Walsh MC, (eds). Fanaroff and Martin's neonatal-perinatal medicine diseases of the fetus and infant. 8th ed. Philadelphia: Mosby Elsevier, 2006: 1122-1146.
(2.) Lakhoo K. Management of congenital cystic adenomatous malformations of the lung. Arch Dis Child Fetal Neonatal Ed 2009; 94(1): F73-6.
(3.) Mann S, Wilson RD, Bebbington MW, Adzick NS, Johnson MP. Antenatal diagnosis and management of congenital cystic adenomatoid malformation. Semin Fetal Neonatal Med 2007; 12(6): 477-481.
(4.) Stocker JT, Madewell JE, Drake RM. Congenital cystic adenomatoid malformation of the lung. Classification and morphologic spectrum. Hum Pathol Mar 1977; 8(2): 155-171.
(5.) Nagata K, Masumoto K, Tesiba R, Esumi G, Tsukimori K, Norio W, Taguchi T. Outcome and treatment in an antenatally diagnosed congenital cystic adenomatoid malformation of the lung. Pediatr Surg Int 2009; 25(9): 753-757.
(6.) Crombleholme TM, Coleman B, Hedrick H, Liechty K, Howell L, Flake AW, Johnson M, Adzick NS. Cystic adenomatoid malformation volume ratio predicts outcome in prenatally diagnosed cystic adenomatoid malformation of the lung. J Pediatr Surg 2002; 37(3): 331-338.
(7.) Laberge JM, Flageole H, Pugash D, Khalife S, Blair G, Filiatrault D, Russo P, Lees G, Wilson RD. Outcome of the prenatally diagnosed congenital cystic adenomatoid lung malformation: a Canadian experience. Fetal Diagn Ther 2001; 16(3): 178-186.
(8.) Adzick NS. Open fetal surgery for life-threatening fetal anomalies. Semin Fetal Neonatal Med 2010; 15(1): 1-8.
(9.) Cetinkaya E, Agizkuru T Comert S, Vitrinel A. Konservatif tedavi ile gerileyen bir konjenital kistik adenomatoid malformasyon olgusu. Bakirkoy Tip Dergisi 2008; 4: 73-75.
(10.) Ozdemir OMA, Ergin H, Karaca A, Koltuksuz U, Karabulut N, Yalcin N. Konjenital kistik adenomatoid malformasyonlu bir olgu sunumu. Turkiye Klinikleri J Med Sci 2010; 30(2): 798-802.
Salih Kalay , Osman Oztekin , Gonul Tezel , Erdem Basaran , Aygul Kernak , Mustafa Akcakus , Nihal Oygur 
 Akdeniz University Medical Faculty, Department of Pediatrics, Division of Neanatology, Antalya, Turkey
 Akdeniz University Medical Faculty, Department of Pediatrics, Antalya, Turkey
 Akdeniz University Medical Faculty, Department of Radiology Radyoloji, Antalya, Turkey
Address for Correspondence: Salih Kalay MD, Akdeniz University Medical Faculty, Department of Pediatrics, Division of Neanatology, Antalya, Turkey
E-mail: firstname.lastname@example.org Received: 08.24.2010 Accepted: 01.13.2011
Turkish Archives of Pediatrics, published by Galenos Publishing
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|Title Annotation:||Case Report|
|Author:||Kalay, Salih; Oztekin, Osman; Tezel, Gonul; Basaran, Erdem; Kernak, Aygul; Akcakus, Mustafa; Oygur,|
|Publication:||Turkish Pediatrics Archive|
|Date:||Dec 1, 2012|
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