Journal of Dr. NTR University of Health Sciences

REVIEW ARTICLE
Year
: 2015  |  Volume : 4  |  Issue : 2  |  Page : 65--74

Disorders of lung development


Srikanti Raghu 
 Department of TB and Chest Diseases, Guntur Medical College and Chest Physician, Government Fever Hospital, Guntur, Andhra Pradesh, India

Correspondence Address:
Srikanti Raghu
Department of TB and Chest Diseases, Guntur Medical College and Chest Physician, Government Fever Hospital, Amaravathi Road, Guntur - 522 034, Andhra Pradesh
India

Abstract

Congenital lung malformations rarely occur but could represent an important cause of respiratory distress in the newborn. As the development of the respiratory tract occurs according to a strict timetable, abnormalities present at birth may be accurately dated to disturbances of intercellular relationships that have occurred at fixed points in intrauterine life. Major structural abnormalities of the respiratory tract are usually fatal or frequently diagnosed before birth or early in postnatal life. Other developmental anomalies may not manifest themselves until much later in life. Antenatal diagnosis by ultrasound scan permits early recognition and thus adequate management. After birth, thoracic-computed tomography is the most useful diagnostic tool. Management of the lesions is based on the characteristics of the lesion and the clinical status of the patient. The pathogenesis, clinical presentation, diagnostic tools, and management options of the important congenital lung malformations are briefly reviewed.



How to cite this article:
Raghu S. Disorders of lung development.J NTR Univ Health Sci 2015;4:65-74


How to cite this URL:
Raghu S. Disorders of lung development. J NTR Univ Health Sci [serial online] 2015 [cited 2022 Oct 2 ];4:65-74
Available from: https://www.jdrntruhs.org/text.asp?2015/4/2/65/158571


Full Text

 INTRODUCTION



Human lung growth starts as a primitive lung bud in early embryonic life and undergoes several morphological stages which continue into postnatal life. Lung development requires the integration of multiple regulatory factors that mediate patterns of cell proliferation, differentiation, migration, and death. Understanding these processes could provide important insight into controlling cell differentiation and regeneration for therapeutic purposes.

Congenital lung malformations are a group of rare conditions that can be the source for important morbidity and mortality in infants and children. An understanding of their presentation and imaging features is important for the physician. Whenever we come across an abnormal chest X-ray (CXR) whose diagnosis is uncertain, one should rule out congenital lung anomalies.

 Stages of Lung Development and Associated Congenital Anomalies



In the human embryo, development of lung starts as early as 3 weeks of embryonic life and continues into postnatal life up to 8 years. [1] The structural and vascular development of the lung is closely related and progresses simultaneously in the human fetus. The events of antenatal growth and development of human lung have been divided into five distinct but overlapping stages. [1] These stages and the associated lung anomalies have been described in [Table 1]. [2],[3],[4],[5] {Table 1}

For easy understanding, the developmental disorders can be divided into:

Tracheobronchial anomalies.Anomalies of lung parenchyma.Anomalies of the pulmonary vasculature.

Some important disorders listed in [Table 2] have been discussed briefly in this article. Other disorders are not discussed because of their extreme rarity.{Table 2}

 Anomalies of Tracheobronchial Tree



Developmental errors of the tracheobronchial tree cannot arise after the 16 th week of intrauterine life since by this time its formation is complete. [6]

Tracheal agenesis

Tracheal agenesis or aplasia refers to the absence of growth in the trachea or part of it. It has a male to female preponderance of 2:1 and is often incompatible with life. [7]

Three main anatomical patterns. Type II, in which the main bronchi join in the midline and communicate with the esophagus by a single fistula, is the most common variety accounting for 60% of cases [Figure 1]. Reconstructive surgery is needed. [8] {Figure 1}

Tracheoesophageal fistula

It is of five types [Figure 2]. Atresia of proximal esophagus and fistula between distal esophagus and trachea is most common variety.{Figure 2}

The H-type tracheoesophageal fistula, in which both the trachea and esophagus remain patent, may be sufficiently small to go undetected until adult life, despite the presence of recurrent symptoms from infancy. [9] May cause aspiration pneumonias, abdominal distension. [10] These can be corrected by early surgical intervention.

Tracheal stenosis

Three types are there:

Diffuse stenosis (30%).Segmental stenosis (50%) (common).Funnel like stenosis (20%).

The condition usually presents in infancy with stridor and respiratory insufficiency. Surgical treatment with various plastic tracheal reconstruction procedures may be necessary. [11]

Tracheomalacia

Indicate excessive weakness and collapsibility of the tracheal walls as a result of abnormally soft or pliable cartilages. [12]

Acquired forms of tracheomalacia occur as a result of prolonged endotracheal intubation and relapsing polychondritis.

Presents in childhood with expiratory airflow obstruction and apneic episodes. In severe cases, surgical intervention with aortopexy and various tracheal splinting procedures may be necessary. [13]

Tracheobronchomegaly

Characterized by unusual width of the trachea and main bronchi. Because of the ineffectiveness of cough, often complicated by lower respiratory infections and bronchiectasis. [14] Presents in young adults. Diagnosis with tracheo-bronchogram and on computed tomography (CT) or magnetic resonance imaging. [15]

 Abnormal Patterns of Bronchial Branching



The abnormalities are:

Additive (often).Subtractive.

The most common major anomaly is a supernumerary right upper lobe bronchus, which may arise anywhere from the trachea or right main bronchus. [16] Absence of an upper lobe bronchus is the most common of the major subtractive abnormalities (0.3%). [16]

The most common segmental anomaly is a double-stem apical lower lobe segmental bronchus (7%), which common on the right side. [17]

Bronchial isomerism

Normal pattern of bronchial branching in either the left or the right lung is mirrored in the contralateral lung, resulting in a so-called bilateral left or right lung. [18]

Bronchial atresia

Result of a developmental interruption of normal bronchial continuity in which a length of bronchus, usually the apicoposterior segmental bronchus of the left upper lobe becomes sealed off from the larger proximal airways to which it may remain connected by thin, uncanalized, fibrous, vestigial strands. [19]

This sealed-off or atretic bronchus becomes distended by bronchial secretions, resulting in the formation of a cystic space or mucocele.

Asymptomatic and incidental finding in young adult. Diagnosis is by CT scan [Figure 3]. [20] {Figure 3}

Surgical excision of the atretic segment by lobectomy or segmentectomy. [21]

 Bronchogenic Cysts (syn. Bronchial Cysts)



Result of abnormal budding of the tracheobronchial tree during the course of its development between the 26 th day and 16 th week of intrauterine life, in which a tracheal or bronchial bud becomes detached from its parent, thereafter developing separately to produce a cystic structure. [22] Common in males and Yemenite Jews.

Classification:

Central (syn. mediastinal) - Arise earlier in the developmental. [23] Peripheral (syn. intraparenchymal, intralobar) - Arises at a later stage. [24]

Pathological features

Bronchogenic cysts vary in size and may reach 10 cm in diameter. [25] They are usually thin-walled, lined by ciliated respiratory epithelium and contain smooth muscle, elastic tissue, cartilaginous trabeculations, and mucous glands. The presence of cartilage in their walls serves to distinguish them from cysts of different origin. A fistulous communication with an adjacent airway with a ball-valve mechanism may cause it to enlarge and present in infancy or exceedingly rarely in young adult life by causing displacement of normal lung. [26] Intact and uninfected cysts contain clear fluid.

Clinical features

Frequently asymptomatic and may be an incidental finding. Symptoms occur from either a mass effect on adjacent structures or more frequently infection. Rhabdomyosarcoma may occur as a complication. [27]

Radiographic features

Chest X-ray and CT scan: A well-circumscribed, rounded, homogeneous opacity situated either in the mediastinum close to a major airway or in the lung periphery [Figure 4].{Figure 4}

Treatment

Elective surgical resection of the lesion is generally advised. Small asymptomatic cysts or in whom surgery is contra-indicated, cysts can be left in situ or needle aspirated. [28]

Congenital adenomatoid malformation of the lung

Congenital cystic adenomatoid malformation, congenital bronchiectasis or pulmonary cystic disease, accessory lung.

It may involve either a part or the whole of a lobe or rarely an entire lung. The affected lobe or lung derives its blood supply from the pulmonary circulation and comprises a firm and airless mass of disorganized pulmonary tissue that lacks a properly defined bronchial system but contains an excess of air passages resembling terminal bronchioles and often includes mucous cysts of varying sizes. [29]

Stocker et al. classification: [30]

Type I characterized by single or multiple large cysts, was the most common form, accounting for 50% and carrying a good prognosis [Figure 5].{Figure 5}

Type II consisting multiple small cysts of <1 cm in diameter, accounted for 40% of cases and carried a poor prognosis.

Type III carried a very poor prognosis and consisted of a solid airless mass of tissue.

Results from a developmental failure of the proximal bronchial system, arising from the epithelial laryngotracheal bud, to unite in a normal manner with mesodermally derived distal alveolated tissue. [31] About 50% of cases are born prematurely, and 25% are stillborn. [32] Many of those born alive die within a few hours, often with anasarca caused by vena caval compression due to the space-occupying effect of the abnormal tissue mass. Infection of the cysts commonly occurs if the infant survives beyond the neonatal period, although the onset of symptoms may be delayed for 2 or 3 years. [33] The condition may be complicated by pneumothorax. Can be diagnosed antenatally by ultrasound examination. Treatment by surgical resection of the affected parts of the lung. [34]

 Anomalies of The Lung Parenchyma



Agenesis and hypoplasia of the lung

Agenesis

Complete bilateral agenesis of the lungs is extremely rare. [35] Unilateral agenesis of the lung is much less rare and may be present to varying degrees of severity. [32] The left lung is affected more frequently and exhibit other congenital abnormalities, one of the most common being patent ductus arteriosus. [36] Occur in three forms. In the most common form of unilateral agenesis, there is rudimentary bronchus but a complete absence of lung tissue.

Hypoplasia

Mostly etiology is unknown.

Unilateral hypoplasia Conditions that decrease intrathoracic space, [37] Congenital diaphragmatic hernia,Ipsilateral congenital vascular anomalies.Bilateral hypoplasia Oligohydramnios (renal tract disorders or by amniotic fluid leak), [38]Premature rupture of the membranes, Maternal treatment with ACE inhibitors. [39]

Clinical features

Recurrent episodes of lower respiratory tract infection resulting from either imperfect drainage of lung secretions or the spillover of pooled secretions from a blind bronchial stump into initially normal lung tissue. [40]

Chest X-ray

A hemithorax of diminished volume with crowded ribs, elevated hemidiaphragm, and mediastinal displacement to the affected side. The contralateral lung tends to overinflate and may expand across the midline [Figure 6].{Figure 6}

Diagnosis

Bronchoscopy, CT and occasionally pulmonary angiography. [41]

 Congenital Abnormalities of Lobulation



Most common is the azygos lobe. [42] Present in about 0.25% of chest radiographs An azygos lobe is really the medial portion of a bifurcated right upper lobe regarded as an anatomical variation. Normally, the entire right upper lobe lies lateral to the azygos vein. But in the case of this anomaly the right upper lobe assumes a bifid configuration so that a portion of the lung lies on either side of the venous arch formed by the azygos vein. [42] The azygos fissure is a supernumerary fissure and is bounded on each side by a layer of visceral and parietal pleura. CXR: Thin outwardly convex line ending in a small triangular shadow at its lower end [Figure 7].{Figure 7}

 Lung Sequestration



Characterized by the formation of an island of abnormal unventilated lung tissue that has no normal communication with the bronchial system and derives its arterial supply from the systemic rather than the pulmonary circulation.

Develops as a result of the formation of an accessory lung bud distal to the normal laryngotracheal bud on the ventral aspect of the primitive foregut. As this anomalous bronchial tissue grows, it becomes invested by primitive respiratory mesenchyme. The amount of mesenchyme determines the size of the sequestration and results in the development of its respiratory bronchioles and alveolar tissue. [43]

Two types [Table 3]:{Table 3}

Intralobar sequestration.

Extralobar sequestration. [44]

Intralobar sequestration: More common. The abnormal lung tissue is contained within the substance of normal lung tissue that completely surrounds it. [32]

Extralobar sequestration (accessory lung without a bronchial connection'). [32]

Abnormal lung tissue, although lying close to normal lung, is situated outside the pleural coverings of the lung and is indeed invested by its own separate pleural membranes.

Both forms occur more commonly in the left hemithorax. [32] Probably due to delayed closure of the primitive pleuroperitoneal canal on the left side and also the absence of hepatic tissue on the left provides additional space in which abnormal tissue may develop.

Clinical features

Extralobar sequestrations are frequently diagnosed in the first year of life because of associated multiple congenital abnormalities.

Manifest as nonspecific symptoms of lower respiratory tract infection or with recurrent pneumonic episodes, occasionally hemoptysis, which may be massive, mucocele, and fistula formation.

Chest X-ray

Intralobar

Persistent homogenous opacity situated in either of the posterior basal segments. Air-fluid level appears if the cysts get infected.

Extralobar

Small homogenous opacity contiguous with the left hemidiaphragmatic shadow.

Computed tomography scan confirms the diagnosis [Figure 8]. Retrograde thoracic aortography to demonstrate feeding vessel.{Figure 8}

Treatment

Resection of a symptomatic pulmonary sequestration is indicated. Any infection that might be present is first treated with appropriate antibiotics. [45]

Intralobar sequestrations: Segmental resection or lobectomy.

Extralobar sequestration: Resected without disturbing normal lung.

 Anomalies of The Pulmonary Vasculature



Persistent pulmonary hypertension of new-born

Due to disturbances of remodeling that result in the excessive muscularization of intra-acinar arteries. Disturbances are due to maternal ingestion of aspirin which leads to the premature closure of ductus arteriosus. [46]

Absent pulmonary artery trunk

The pulmonary artery trunk may be completely absent as a result of agenesis of the primitive sixth branchial arch or of developmental failure of the septum that normally divides the truncus arteriosus into the aorta and pulmonary artery trunk. [47]

Absent unilateral pulmonary artery

Consequence of the failure of either the left or right side of the primitive sixth branchial arch to develop in the embryo. The lung parenchyma on the affected side receives its blood supply systemically, most frequently from enlarged bronchial vessels. The left and right pulmonary arteries are affected with equal frequency but the right-sided lesion is more common in adult life because absence of the left pulmonary artery is strongly associated with congenital heart disease and therefore with increased early mortality. [48],[49]

Pulmonary artery stenosis [50]

Whereas patients who present in infancy usually due to pulmonary hypertension as a result of associated cardiac disease. Adults may be asymptomatic, the diagnosis being made following a chest radiograph requested for some other reason. The chest radiograph shows a small hilar shadow and a small hyperlucent lung on the involved side. The diagnosis may be confirmed and differentiated from Macleod's syndrome by a perfusion lung scan or pulmonary angiogram, both of which show a complete lack of perfusion on the affected side.

 Anomalous Origin of The Left Pulmonary Artery



The failure of the pulmonary arterial plexus of the left lung and the left part of the sixth primitive branchial arch to connect in the normal way may result in the left pulmonary artery arising in anomalous fashion from the right pulmonary artery.

Course

This aberrant left pulmonary artery loops around the right main bronchus like a sling and runs a peculiar course between the lower end of the trachea anteriorly and the esophagus posteriorly, thereby crossing the midline to enter the left hilum. A condition known as "sling" pulmonary artery syndrome. [51]

Symptoms are due to the pressure on the left main bronchus, trachea, and esophagus.

Chest X-ray

On the lateral view appears as a rounded opacity between the air-filled trachea and esophagus at the level of the carina. A barium swallow may provide supportive evidence.

The diagnosis is confirmed by pulmonary angiography.

 Anomalous Systemic Pulmonary Perfusion



Anomalous venous drainage of a lung arises as a result of persistent communications between the embryonic system of cardinal veins and the pulmonary venous plexus. These communications develop into aberrant pulmonary veins that drain systemically, usually into the inferior vena cava that creates a left-to-right shunt. [52]

Scimitar syndrome: (Syn: Congenital pulmonary venolobar syndrome/vena cava bronchovascular syndrome).

The most consistent feature is the drainage of part of the right lung by an anomalous scimitar-shaped pulmonary vein that passes through the lung running parallel to, but separate from, the mediastinal structures before joining the inferior vena cava, usually below the diaphragm. [53]

Other features:

An anomalous systemic arterial supply to the territory drained by the scimitar veinHypoplasia of the right lung [54] Cardiac dextropositionDiaphragmatic abnormalities.

The condition is most frequently diagnosed in adult life in asymptomatic subjects following a routine chest radiograph.

Chest X-ray

Shows a characteristic curvilinear vascular density in the right lower lung with features of ipsilateral loss of lung volume [Figure 9].{Figure 9}

Pulmonary arteriovenous malformations and telangiectasia

(Syn: Pulmonary arteriovenous fistula/pulmonary arteriovenous aneurysm/pulmonary angioma/pulmonary haemangioma/pulmonary cavernous angioma).

Probably originate during the development of the primitive pulmonary vascular plexus, when an anastomotic vessel arises which presents a significantly lower resistance to flow than that provided by the surrounding pulmonary vascular bed. [31] About 95% of arteriovenous malformations derive their blood supply from branches of the pulmonary artery and drain into the pulmonary venous circulation. [55]

Pulmonary telangiectasis results if there is a fistulous communication between a small peripheral arteriole and venule. If large numbers of these defects are present and if they are diffusely distributed, then the condition may be referred to as pulmonary telangiectasia. [56]

Arteriovenous malformations are slightly more common in women than men. [52]

Clinical features

Mean age at diagnosis was 40 years. [55] Occasionally, the condition is detected in infancy, especially in patients with hereditary telangiectasia. More than half of all patients have no symptoms. [57]

The respiratory symptom most commonly present at the time of diagnosis is dyspnea, haemoptysis being less frequent. [55] A bruit is audible over the lesion in more than half of all patients with arteriovenous malformations. [55] Cyanosis may be present as a result of right-to-left shunting and, when this is present, finger clubbing is a frequent accompaniment.

Symptoms are unlikely to occur in the case of single discrete lesions provided that the radiographic diameter of the malformation is <2 cm.

Radiographic features

Chest X-ray

One or more rounded lobulated or tortuous opacities, frequently occupying the periphery of the lower lung fields [Figure 10]. [58] Serial radiographs may show gradual enlargement of the malformations with the passage of time. The shadows are often well-defined, and the radiograph may be misinterpreted as indicating metastatic tumor. [59] {Figure 10}

The radiographic size of the discrete lesion may be shown to vary according to intrathoracic pressure, increasing in size during a Muller maneuver and becoming smaller with a valsalva maneuver. [60]

Computed tomography chest

Useful method for identification and delineation of lesions and for identification of feeding or draining the vessel. [61]

Bilateral pulmonary angiography

Confirms the diagnosis in all but a few cases. This investigation, together with CT, should always be undertaken if surgical treatment is being considered. [62]

Treatment

Active treatment is desirable for lesions with feeding vessels >3 mm in diameter. [63]

Discrete peripheral arteriovenous malformations may be removed by local resection with ligation of the afferent and efferent vessels. Deeper and more extensive lesions may be removed by wedge resection, segmental resection or lobectomy with the general aim of conserving as much lung tissue as possible. [59]

When the arteriovenous malformations are multiple or bilateral, selective treatment is indicated and embolization or occlusion techniques, using balloons or steel coils, have been used with success. [63] In some cases of multiple lesions and telangiectasia with cyanosis, lung transplantation can be tried. [64]

References

1Fishman AP, Alfred P. Fishman, Elias JA, Fishman JA, Grippi MA, Senior RM, Pack AI . Development and Growth of the lung. Fishman's Pulmonary Diseases and Disorders. 4 th ed., Vol. 5. 2008. p. 91-114.
2Kotecha S. Lung growth: Implications for the newborn infant. Arch Dis Child Fetal Neonatal Ed 2000;82:F69-74.
3Hislop AA, Pierce CM. Growth of the vascular tree. Paediatr Respir Rev 2000;1:321-7.
4Kotecha S. Lung growth for beginners. Paediatr Respir Rev 2000;1:308-13.
5Merkus PJ, ten Have-Opbroek AA, Quanjer PH. Human lung growth: A review. Pediatr Pulmonol 1996;21:383-97.
6Dankert-Roelse JE, te Meerman GJ. Long term prognosis of patients with cystic fibrosis in relation to early detection by neonatal screening and treatment in a cystic fibrosis centre. Thorax 1995;50:712-8.
7Altman RP, Randolph JG, Shearin RB. Tracheal agenesis: Recognition and management. J Pediatr Surg 1972;7:112-8.
8Hiyama E, Yokoyama T, Ichikawa T, Matsuura Y. Surgical management of tracheal agenesis. J Thorac Cardiovasc Surg 1994;108:830-3.
9Mullard KS. Congenital tracheoesophageal fistula without atresia of the esophagus. J Thorac Surg 1954;28:39-54.
10Schneider KM, Becker JM. The 'H type tracheo-esophageal fistula in infants and children. Surgery 1962;51:677.
11Andrews TM, Cotton RT, Bailey WW, Myer CM 3 rd , Vester SR. Tracheoplasty for congenital complete tracheal rings. Arch Otolaryngol Head Neck Surg 1994;120:1363-9.
12Landing BH. Syndromes of congenital heart disease with tracheobronchial anomalies. Edward B. D. Neuhauser Lecture, 1974. Am J Roentgenol Radium Ther Nucl Med 1975;123:679-86.
13Filler RM, Messineo A, Vinograd I. Severe tracheomalacia associated with esophageal atresia: Results of surgical treatment. J Pediatr Surg 1992;27:1136-40.
14Guest JL Jr, Anderson JN. Tracheobronchomegaly (Mounier-Kuhn syndrome). JAMA 1977;238:1754-5.
15Smith DL, Withers N, Holloway B, Collins JV. Tracheobronchomegaly: An unusual presentation of a rare condition. Thorax 1994;49:840-1.
16Mehta AC, Ahmad M, Golish JA, Buonocore E. Congenital anomalies of the lung in the adult. Cleve Clin Q 1983;50:401-16.
17Atwell SW. Major anomalies of the tracheobronchial tree: With a list of the minor anomalies. Dis Chest 1967;52:611-5.
18Landing BH, Lawrence TY, Payne VC Jr, Wells TR. Bronchial anatomy in syndromes with abnormal visceral situs, abnormal spleen and congenital heart disease. Am J Cardiol 1971;28:456-62.
19Warner JO, Rubin S, Heard BE. Congenital lobar emphysema: A case with bronchial atresia and abnormal bronchial cartilages. Br J Dis Chest 1982;76:177-84.
20Jederlinic PJ, Sicilian LS, Baigelman W, Gaensler EA. Congenital bronchial atresia. A report of 4 cases and a review of the literature. Medicine (Baltimore) 1987;66:73-83.
21Meng RL, Jensik RJ, Faber LP, Matthew GR, Kittle CF. Bronchial atresia. Ann Thorac Surg 1978;25:184-92.
22Bucher U, Reid L. Development of the intrasegmental bronchial tree: The pattern of branching and development of cartilage at various stages of intra-uterine life. Thorax 1961;16:207-18.
23Schmidt FE. Drapanas annals of thoracic surgery, Bronchial cysts. Br M J 1973;2: 501-2.
24Rogers LF, Osmer JC. Bronchogenic cyst. A review of 46 cases. Am J Roentgenol Radium Ther Nucl Med 1964;91:273-90.
25Mayo P, Saha SP, Long GA, Powell C. Surgical management of congenital lung cysts: A 16-year review. J Ky Med Assoc 1984;82:327-30.
26Tarpy SP, Kornfeld H, Moroz K, Lazar HL. Unusual presentation of a large tension bronchogenic cyst in an adult. Thorax 1993;48:951-2.
27Murphy JJ, Blair GK, Fraser GC, Ashmore PG, LeBlanc JG, Sett SS, et al. Rhabdomyosarcoma arising within congenital pulmonary cysts: Report of three cases. J Pediatr Surg 1992;27:1364-7.
28Bolton JW, Shahian DM. Asymptomatic bronchogenic cysts: What is the best management? Ann Thorac Surg 1992;53:1134-7.
29Parodi-Hueck L, Densler JF, Reed RC, Poulos P, Shulman MW. Congenital cystic adenomatoid malformation of the lung. Case report and review of the literature. Clin Pediatr (Phila) 1969;8:327-30.
30Stocker JT, Drake RM, Madwell JE. Cystic and congenital lung disease in the newborn. In: Rosenberg H, Blonde R, editors. Prospectives in Pediatric Pathology. Vol 4. Chicago: Year Book Medical Publishers; 1978, p. 93-154.
31Spencer H. Pathology of lung, 4 th Ed. Oxford, UK: Pergamon Press, 1985, p. 778-9.
32Landing BH, Dixon LG. Congenital malformations and genetic disorders of the respiratory tract (larynx, trachea, bronchi, and lungs). Am Rev Respir Dis 1979;120:151-85.
33Wexler HA, Dapena MV. Congenital cystic adenomatoid malformation. A report of three unusual cases. Radiology 1978;126:737-41.
34Ng KJ, Hasan N, Gray ES, Jeffrey RR, Youngson GG. Intralobar bronchopulmonary sequestration: Antenatal diagnosis. Thorax 1994;49:379-80.
35DeBuse PJ, Morris G. Bilateral pulmonary agenesis, oesophageal atresia, and the first arch syndrome. Thorax 1973;28:526-8.
36WIER JA. Congenital anomalies of the lung. Ann Intern Med 1960;52:330-48.
37Wigglesworth JS, Desai R, Guerrini P. Fetal lung hypoplasia: Biochemical and structural variations and their possible significance. Arch Dis Child 1981;56:606-15.
38Husain AN, Hessel RG. Neonatal pulmonary hypoplasia: An autopsy study of 25 cases. Pediatr Pathol 1993;13:475-84.
39Shotan A, Widerhorn J, Hurst A, Elkayam U. Risks of angiotensin-converting enzyme inhibition during pregnancy: Experimental and clinical evidence, potential mechanisms, and recommendations for use. Am J Med 1994;96:451-6.
40Borja AR, Ransdell HT Jr, Villa S. Congenital developmental arrest of the lung. Ann Thorac Surg 1970;10:317-26.
41Daves ML, Walsh JA. Minihemithorax. Am J Roentgenol Radium Ther Nucl Med 1970;109:528-30.
42Grant JC. An Atlas of Anatomy. Baltimore: Williams & Wilkins; 1962.
43Stovin PG. Early lung development. Thorax 1985;40:401.
44Smith RA. A theory of the origin of intralobar sequestration of lung. Thorax 1956;11:10-24.
45Haller JA Jr, Golladay ES, Pickard LR, Tepas JJ 3 rd , Shorter NA, Shermeta DW. Surgical management of lung bud anomalies: Lobar emphysema, bronchogenic cyst, cystic adenomatoid malformation, and intralobar pulmonary sequestration. Ann Thorac Surg 1979;28:33-43.
46Murphy JD, Rabinovitch M, Goldstein JD, Reid LM. The structural basis of persistent pulmonary hypertension of the newborn infant. J Pediatr 1981;98:962-7.
47Manhoff LJ Jr, Howe JS. Absence of the pulmonary artery; a new classification for pulmonary arteries of anomalous origin; report of a case of absence of the pulmonary artery with hypertrophied branchial arteries. Arch Pathol (Chic) 1949;48:155-70.
48Steinberg I. Congenital absence of a main branch of the pulmonary artery; report of three new cases associated respectively with bronchiectasis, atrial septal defect and Eisenmenger's complex. Am J Med 1958;24:559-67.
49Pool PE, Vogel JH, Blount SG Jr. Congenital unilateral absence of a pulmonary artery. The importance of flow in pulmonary hypertension. Am J Cardiol 1962;10:706-32.
50Liggins GC, Phillips LI. Rubella embryopathy. An interim report on a New Zealand epidemic. Br Med J 1963;1:711-3.
51Philp T, Sumerling MD, Fleming J, Grainger RG. Aberrant left pulmonary artery. Clin Radiol 1972;23:153-9.
52Ellis K, Seaman WB, Griffith SP, Berdon WE, Baker DH. Some congenital abnormalities of the pulmonary arteries. Semin Roentgenol 1967;2:325.
53Kiely B, Filler J, Stone S, Doyle EF. Syndrome of anomalous venous drainage of the right lung to the infenor vena cava: A review of 67 reported cases and three new cases in children. Am J Cardiol 1967;20:102.
54Mathey J, Galey JJ, Logeais Y, Santoro E, Vanetti A, Maurel A, Wuerflein R. Anomalous pulmonary venous return into inferior vena cava and associated bronchovascular anomalies (the scimitar syndrome): Report of three cases and review of the literature. Thorax 1968;23:398.
55Dines DE, Arms RA, Bernatz PE, Gomes MR. Pulmonary arteriovenous fistulas. Mayo Clin Proc 1974;49:460-5.
56Currarino G, Willis KW, Johnson AF Jr, Miller WW. Pulmonary telangiectasia. AJR Am J Roentgenol 1976;127:775-9.
57Mitchell RO, Austin EH 3 rd . Pulmonary arteriovenous malformation in the neonate. J Pediatr Surg 1993;28:1536-8.
58Leroux BT. Pulmonary "hamartomata. Thorax 1964;19:236-43.
59Dines DE, Seward JB, Bernatz PE. Pulmonary arteriovenous fistulas. Mayo Clin Proc 1983;58:176-81.
60Steinberg I. Diagnosis and surgical treatment of pulmonary arteriovenous fistula. Report of three new and review of nineteen consecutive cases. Surg Clin North Am 1961;41:523.
61Remy J, Remy-Jardin M, Wattinne L, Deffontaines C. Pulmonary arteriovenous malformations: Evaluation with CT of the chest before and after treatment. Radiology 1992;182:809-16.
62Flower CD. Imaging pulmonary arteriovenous malformations. Br Med J (Clin Res Ed) 1987;294:1633-4.
63White RI Jr, Lynch-Nyhan A, Terry P, Buescher PC, Farmlett EJ, Charnas L, et al. Pulmonary arteriovenous malformations: Techniques and long-term outcome of embolotherapy. Radiology 1988;169:663-9.
64Armitage JM, Fricker FJ, Kurland G, Hardesty RL, Michaels M, Morita S, et al. Pediatric lung transplantation. The years 1985 to 1992 and the clinical trial of FK 506. J Thorac Cardiovasc Surg 1993;105:337-45.