|Year : 2015 | Volume
| Issue : 2 | Page : 53-56
Congenital cystic adenomatoid malformation of lung in fetus: Report of two cases with brief review of literature
Anuradha G Patil, Shabnam Karangadan, Vatsala Kishore
Department of Pathology, Mahadevappa Rampure Medical College, Gulbarga, Karnataka, India
|Date of Web Publication||16-Jun-2015|
Anuradha G Patil
Department of Pathology, Mahadevappa Rampure Medical College, Gulbarga - 585 105, Karnataka
Source of Support: None, Conflict of Interest: None
Congenital cystic adenomatoid malformations (CCAMs), also known as congenital pulmonary airway malformation is a developmental, non-hereditary, hamartomatous abnormality of lung with unknown etiology. It is a rare disease with an incidence of 1 in 25,000 to 1 in 35,000. It is a disease of infancy with most of the cases diagnosed within first 2 years of life. We report autopsy findings of two fetuses with CCAM (Stocker Type I and IV) with brief review of literature.
Keywords: Congenital cystic adenomatoid malformation, fetal autopsy, lung
|How to cite this article:|
Patil AG, Karangadan S, Kishore V. Congenital cystic adenomatoid malformation of lung in fetus: Report of two cases with brief review of literature. J Assoc Chest Physicians 2015;3:53-6
|How to cite this URL:|
Patil AG, Karangadan S, Kishore V. Congenital cystic adenomatoid malformation of lung in fetus: Report of two cases with brief review of literature. J Assoc Chest Physicians [serial online] 2015 [cited 2021 Apr 10];3:53-6. Available from: https://www.jacpjournal.org/text.asp?2015/3/2/53/158854
| Introduction|| |
Congenital cystic adenomatoid malformation (CCAM) is an uncommon anomaly characterized by multicystic lesions due to proliferation of the respiratory bronchioles. Adenomatoid appearance of the lung tissue was first described as a distinct disease entity by Chi'in and Tang in 1949. In 1977, Stocker et al., classified CCAM into three histopathological groups. An expanded classification of five types was further proposed in 2002. The etiology remains unknown, but a disturbed interaction between mesodermal and ectodermal components of the lung during embryonic development has been suggested.  It is a rare lesion with incidence of 1 in 25,000 to 1 in 35,000 pregnancies and represents 25% of congenital lung malformations and 95% of congenital lung lesions.  Eighty percent of the lesions present in neonatal period; however, there are reports even in adult population.  Here, we have described two cases of CCAM, Stocker Type I and IV, which were diagnosed by fetal autopsy.
| Case Reports|| |
A 25-year-old G2 P1 L1, of nonconsanguineous marriage, had a normal antenatal course until 20 weeks of gestation. In routine ultrasound examination, a large cystic lesion in fetal chest was noted. Her past medical history and family history were unremarkable. Repeat ultrasound scans revealed a 2.7 × 2.5 cm cystic lesion in right hemithorax, displacing the cardia to left side [Figure 1]. Fetal stomach and diaphragm were in normal location. Based on ultrasonogram findings, CCAM felt to be the most likely diagnosis.Given the relative risk of pulmonary hypoplasia and nonimmune hydrops fetalis, the parents desired to undergo medical termination of pregnancy. Labor was induced by T. misoprost p/v and abortus was expelled weighing 500 g. Fetus was received for autopsy [Figure 2].
|Figure 1: Ultrasound image showing large cystic lesion in right hemithorax, measuring 2.7×2.5 cm. Cardia displaced to left side with normal axis and vascular connections|
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On autopsy, it was a male fetus weighing 400 g. External examination did not reveal any anomaly. On internal examination all organs were in situ [Figure 3]a. A single cyst measuring 2.6 × 2.5 cm was found in posterior aspect of right lung [Figure 3]b. On histology, right lung showed normal lung histology of canalicular stage appropriate for the gestational age [Figure 4]a. The section from the cyst shows cyst wall lined by pseudostratified columnar epithelium with thin fibromuscular septa [Figure 4]b.
|Figure 3: (a) Enbloc of organs removed during autopsy (b) Large cyst measuring 2.6×2.5 cm noted arising from posterior aspect of right lung|
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|Figure 4: (a) Case 1: Section of adjacent lung showing immature lung tissue in canalicular stage (hematoxylin and eosin (H and E),×100) (b) Case 1: Section from cyst showing cyst wall lined by pseudostratified columnar epithelium, and having thin fibromuscular septa (H and E, ×400)|
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All other visceral organs were well-developed for gestational age.With the above features, a pathological diagnosis of CCAM Stocker type I was offered.
A 22-year-old primigravida, with history of 40 weeks of amenorrhea sought routine antenatal check-up. Her blood and biochemical investigations were within normal limits. Routine anomalous scan revealed multiple cysts in left hemithorax. Pregnancy was terminated after informed consent and the fetus was sent for pathological evaluation.
On autopsy, it was a female fetus of 2.5 kg. External examination was normal. On internal examination, all organs were in situ. Two cysts were located in base of left lung, which were bluish in color and measured 2 × 2 cm and 2 × 1 cm, respectively. On histology, left lung revealed two cysts lined by flattened alveolar type epithelial cells [Figure 5]a and b. All other visceral organs were congested, but well developed for gestational ageand revealed no anomalies. With the above features a pathological diagnosis of CCAM Stocker type IV was offered.
|Figure 5: (a) Case 2: Section from lung shows large cystic spaces with adjacent alveoli (H and E,×100) (b) Case 2: Higher magnification of the cyst showing cyst wall lined byflattened alveolar type epithelial cells (H and E, ×400)|
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| Discussion|| |
CCAM of the lung is caused by anomalous fetal development of terminal respiratory structures, resulting in adenomatoid proliferation of bronchiolar elements and cyst formation leading to enlargement of the affected lobe. The clinical spectrum varies depending on the extent of malformation in the lung and associated conditions. Some authors have observed predilection of the right lung over the left for this anomaly. Involvement of an entire lung is distinctly rare. Single lobe involvement is most common. 
Based on the anatomical changes, development of human lung is subdivided into embryonal (3-7 weeks), pseudoglandular (7-17 weeks), canalicular (17-29 weeks), saccular (24-36 weeks), and alveolar (36 weeks to maturity). 
CCAM is characterized with abnormal differentiation of immature bronchioles and abnormal breath pattern during morphogenesis of the lung. These were recently described into five types by Stocker et al.,  as:
Type 0: Acinary dysplasia-tracheobronchiolar origin
Type I: Bronchi/bronchiole originated multiple/dominant large cystic type
Type II: Bronchiole originated multiple small cystic type
Type III: Bronchiole without alveoli originated multiple small cystic or solid type
Type IV: Distal acinary originated peripheral cystic type [Table 1].
|Table 1: Pathologic features of congenital cystic adenomatoid malformation lung (according to stocker)|
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It may be associated with pulmonary hypoplasia, heart failure, polihydramnios, mediastinal shift, and particularly nonimmune fetal hydrops. However, this lesion may rarely regress spontaneously at prenatal period.  The association of recombinant chromosome 18 in association with CCAM has been described in some cases. 
The diagnostic ultrasonographic feature of CCAM is, multicystic lesions at the lung field and common differential diagnosis includes diaphragmatic hernia, bronchogenic cyst, cystic fibrosis, congenital lobar emphysema, and pulmonary sequestration. 
The main complication of CCAM in neonatal period is compression of the mediastinal structure producing cardiovascular compromise. Serial antenatal sonographic evaluation, good obstetric care, and delivery at a tertiary care center are preferred plan of treatment for antenataly detected cases. Postnatal and in adult patients, lobectomy is the treatment of choice for symptomatic cases. ,
Prognosis also depends on Stocker type, type I lesions carry overall good prognosis. In type II lesion, it is the associated anomalies that determine the prognosis. Type III lesions carry bad prognosis as they are usually large and presents with cardiovascular compromise. Overall bilateral involvement, associated with hydrops and associated congenital anomalies carry poor prognosis. 
| Conclusion|| |
CCAM is a rare developmental malformation of lung. It is usually diagnosed in fetal or neonatal life. Serial ultrasonographic evaluation, fetal lung mass size, and fetal echocardiography are needed for management of antenatally detected cases. We report these cases for their infrequent occurrence and limited reports in literature.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]