The continuum of pulmonary developmental anomalies

Congenital lung malformations

Congenital lung malformations (CLMs) are rare developmental anomalies of the lung, including congenital pulmonary airway malformations (CPAM), bronchopulmonary sequestration, congenital lobar overinflation, bronchogenic cyst and isolated congenital bronchial atresia. CLMs occur in 4 out of 10,000 live births. Postnatal presentation ranges from an asymptomatic infant to respiratory failure. CLMs are typically diagnosed with antenatal ultrasonography and confirmed by chest CT angiography in the first few months of life. Although surgical treatment is the gold standard for symptomatic CLMs, a consensus on asymptomatic cases has not been reached. Resection, either thoracoscopically or through thoracotomy, minimizes the risk of local morbidity, including recurrent infections and pneumothorax, and avoids the risk of malignancies that have been associated with CPAM, bronchopulmonary sequestration and bronchogenic cyst. However, some surgeons suggest expectant management as the incidence of adverse outcomes, including malignancy, remains unknown. In either case, a planned follow-up and a proper transition to adult care are needed. The biological mechanisms through which some CLMs may trigger malignant transformation are under investigation. KRAS has already been confirmed to be somatically mutated in CPAM and other genetic susceptibilities linked to tumour development have been explored. By summarizing current progress in CLM diagnosis, management and molecular understanding we hope to highlight open questions that require urgent attention.

Fetal imaging of congenital lung lesions with postnatal correlation

Congenital lung lesions are a rare group of developmental pulmonary abnormalities that are often first identified prenatally on routine second-trimester US. Congenital pulmonary airway malformation (CPAM) is the most common anomaly while others include bronchopulmonary sequestration, congenital lobar overinflation, bronchogenic cyst and bronchial atresia. Clinical presentation is highly variable, ranging from apparent in utero resolution to severe mass effect with resultant hydrops fetalis and fetal demise. Differentiation among these lesions can be challenging because overlapping imaging features are often present. The roles of the radiologist are to identify key imaging findings that help in diagnosing congenital lung lesions and to recognize any ominous features that might require prenatal or perinatal intervention. High-resolution US and complementary rapid-acquisition fetal MRI provide valuable information necessary for lesion characterization. Postnatal US and CT angiography are helpful for lesion evaluation and for possible surgical planning. This article reviews the embryology of the lungs, the normal prenatal imaging appearance of the thorax and its contents, and the prenatal and neonatal imaging characteristics, prognosis and management of various congenital lung lesions.

Pulmonary Sequestration

The purpose of this study was to determine the prevalence of enlargement of the azygos system in the case of lung sequestration and its potential usefulness in the differential diagnosis of lower lobe opacities. Seven consecutive adult cases of pulmonary sequestrations were retrospectively enrolled; 4 sequestrations were proved surgically and all 7 angiographically. A group of 50 consecutive patients with a normal chest CT were used as controls. Another group consisted of 25 consecutive patients identified on the basis of an opacity in a posterobasal location on chest CT. For the 3 groups, the maximum diameter of the azygos and hemiazygos veins was measured, the level of measurement located between the upper poles of the kidneys and the confluence of inferior pulmonary veins into the left atrium. The diameter of the azygos veins (mean 10.4±5.1 mm) and of the hemiazygos veins (mean 7.1±3.0 mm) in the sequestration group was significantly larger than the diameter of the azygos and hemiazygos veins in the control group (mean 5.7±2.5 mm, and 3.4±2.4 mm, respectively), as well as in the study group (mean 5.9±2.6 mm and 3.3±2.6 mm, respectively). Our results suggest that enlargement of the azygos system in association with a posterobasal chest opacity, although nonspecific, may be a useful additional CT sign of sequestration.

A Pulmonary Sequestered Segment with an Aberrant Pulmonary Arterial Supply: A Case of Unique Anomaly

We presented a rare case of a 64-year-old man with a combined anomaly of the bronchus and pulmonary artery that was detected incidentally. Computed tomography showed a hyperlucent, aerated sequestered segment of the right lower lung with an independent ectopic bronchus, which had no connection to the other airway. The affected segment was supplied by its own aberrant pulmonary artery branch from the right pulmonary trunk. This anomaly cannot be classified with any of the previously reported anomalies.

Developmental lung malformations in children: recent advances in imaging techniques, classification system, and imaging findings

Congenital lung anomalies represent a diverse group of developmental malformations of the lung parenchyma, arterial supply, and venous drainage, which may present anywhere from the prenatal period through adulthood. It is imperative for radiologists to be aware of imaging techniques and imaging appearance of these anomalies across the pediatric age range. This review presents the spectrum of these lesions that are often encountered in daily clinical practice. Each anomaly is discussed in terms of underlying etiology, clinical presentation, and imaging characterization with emphasis on the most up-to-date research and treatment. Knowledge of these areas is essential for accurate, timely diagnosis, which aids in optimizing patient outcomes.

Multislice CT in congenital bronchopulmonary malformations in children

Congenital bronchopulmonary malformations encompass a wide spectrum of pathologies involving the lungs, trachea and bronchi, pulmonary vessels, and oesophagus. These developmental lesions are often isolated, but the association of two or more anomalies is not infrequent. Contrast-enhanced multidetector computed tomography (MDCT), thanks to multiplanar and 3D reconstructions, allows for detailed studies of these malformations, achieving better accuracy compared with conventional techniques such as chest X-ray, fluoroscopy, ventilation and perfusion scintigraphy and ultrasonography. MDCT is characterised by fast data acquisition and does not require sedation in the majority of cases. The main drawbacks of MDCT are the use of ionising radiation and - in many cases -contrast media. Recently, improved CT scanners and optimised CT protocols have made available to children all the benefits of MDCT, thanks to a significant reduction in radiation dose and an improved risk-benefit ratio. The aim of our paper was to evaluate MDCT in children with bronchopulmonary malformations by reporting our experience (about 2,400 studies in 30 months with a 64-slice MDCT scanner) and comparing it with the available literature.

Pulmonary venous malformation in a 4-year-old boy: a case report

We report a case of a pulmonary venous malformation in a 4-year-old boy who presented with recurrent pneumonia. A radiograph revealed a right infrahilar mass and a hyperlucent right lung. Computed tomography (CT) demonstrated a mass containing intensely enhancing areas and multiple phleboliths located in the right lower lobe and encasing the right bronchus and right inferior pulmonary vein. Magnetic resonance imaging (MRI) precisely revealed the mass demarcation. A right lower lobectomy was performed and a pathological examination confirmed the diagnosis of a venous malformation. To the best of our knowledge, a venous malformation in pulmonary tissue has not been reported in the English literature. Herein, we report a case of a pulmonary venous malformation, with the radiograph, CT, MRI, and blood pool scan findings, along with its pathologic correlation.

Multidetector CT evaluation of congenital lung anomalies

Congenital lung anomalies vary widely in their clinical manifestation and imaging appearance. Although radiographs play a role in the incidental detection and initial imaging evaluation in patients with clinical suspicion of congenital lung anomalies, cross-sectional imaging such as computer tomography (CT) is frequently required for confirmation of diagnosis, further characterization, and preoperative evaluation in the case of surgical lesions. Recently, with the development and widespread availability of multidetector CT scanners, CT has assumed a greater role in the noninvasive evaluation of congenital lung anomalies. The combination of fast speed, high spatial resolution, and enhanced quality of multiplanar reformation and three-dimensional reconstructions makes multidetector CT an ideal noninvasive method for evaluating congenital lung anomalies. In this article, the authors review the multidetector CT technique for evaluation of congenital lung anomalies. Important clinical aspects, characteristic imaging features, and key points that allow differentiation among various anomalies are highlighted for a variety of common and uncommon conditions.

A systematic classification of the congenital bronchopulmonary vascular malformations: dysmorphogeneses of the primitive foregut system and the primitive aortic arch system

PURPOSE

We reviewed the cases of 33 patients from our clinic and 142 patients from the literature with congenital bronchopulmonary vascular malformations (BPVM), systematically analyzed the bronchopulmonary airways, pulmonary arterial supplies, and pulmonary venous drainages, and classified these patients by pulmonary malinosculation (PM).

MATERIALS AND METHODS

From January 1990 to January 2007, a total of 33 patients (17 men or boys and 16 women or girls), aged 1 day to 24 years (median, 2.5 months), with congenital BPVM were included in this study. Profiles of clinical manifestations, chest radiographs, echocardiographs, esophagographs, computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), cardiac catheterizations with angiography, contrast bronchographs, bronchoscopies, chromosomal studies, surgeries, and autopsies of these patients were analyzed to confirm the diagnosis of congenital BPVM. A total of 142 cases from the literature were also reviewed and classified similarly.

RESULTS

The malformations of our 33 patients can be classified as type A isolated bronchial PM in 13 patients, type B isolated arterial PM in three, type C isolated venous PM in two, type D mixed bronchoarterial PM in five, type F mixed arteriovenous PM in one, and type G mixed bronchoarteriovenous PM in nine.

CONCLUSION

Dysmorphogeneses of the primitive foregut system and the primitive aortic arch system may lead to haphazard malinosculations of the airways, arteries, and veins of the lung. A systematic classification of patients with congenital BPVM is clinically feasible by assessing the three basic bronchovascular systems of the lung independently.

Cystic adenomatoid malformation in children: CT histopathological correlation

PURPOSE

This study was performed to assess the accuracy of computed tomography (CT) in classifying the various types of cystic adenomatoid malformation (CAM) of the lung, as described by Stocker et al., taking histopathology as the gold standard.

MATERIALS AND METHODS

We retrospectively reviewed six cases of histologically proven CAM. Chest radiography, chest CT and histopathology results were available for all patients. The CT images were reviewed blinded to the histological findings, and attention was paid to the number and size of cysts so as to classify the lesions into the three groups described by Stocker et al. The classification of lesions based on the CT images was then correlated to the histopathological findings.

RESULTS

Areas with small-sized cysts (<2 cm) were detected by CT in two patients (33.3%), areas with large cysts (>2 cm) were seen in three cases (50%) whereas in the remaining case, the diagnosis was mixed type I and type II CAM. In one patient with type I CAM, an area of low-density consolidation around the cysts was interpreted as CAM in a context of pulmonary sequestration. The CT classification based on Stocker et al.'s categories was in agreement with the histopathological findings in four cases, whereas in the remaining two cases, the lesions were classed as type I or II on CT and as mixed (type I and II) lesions at histopathology. In one case, the CT classification was correct, but the histopathology revealed the coexistence of pulmonary sequestration.

CONCLUSIONS

In our study, there was concordance between CT and histopathology in 66.7% of cases, whereas in 33.3% histopathology revealed areas with mixed grade lesions. CT proved to be accurate in identifying and characterising CAM and provided important information on lesion site and extension.

Congenital bronchopulmonary foregut malformations: concepts and controversies

This article addresses the scope, etiology, important associations and imaging features of congenital bronchopulmonary foregut malformations. Etiologic concepts, including airway obstruction and vascular anomalies, are highlighted. Technical imaging advances, especially CT and MR, have greatly enhanced our diagnostic abilities in evaluating these lesions; however, thorough and careful assessment of all aspects of the malformation is still necessary. Several specific lesions are discussed in more detail, particularly regarding controversial issues in classification, understanding, imaging and management.

Aumento da transparência pulmonar na infância: ensaio iconográfico

Assimetrias torácicas representadas pelo aumento da transparência pulmonar são causas importantes de morbidade na população pediátrica. A avaliação dos pacientes afetados freqüentemente requer múltiplas modalidades de imagem para diagnosticar a anomalia e planejar a correção cirúrgica. Os autores analisam e ilustram os aspectos de assimetrias torácicas comuns e raras, com ênfase nas manifestações radiológicas. A aplicabilidade das diversas modalidades de imagem no diagnóstico e tratamento é avaliada. Diagnósticos diferenciais, assim como armadilhas e dificuldades diagnósticas, são incluídas.

Imaging Evaluation of Congenital Lung Abnormalities in Infants and Children

Congenital lung abnormalities include a wide spectrum of conditions and are an important cause of morbidity and mortality in infants and children. This article discusses focal lung abnormalities and the dysmorphic lung. Pulmonary arteriovenous malformations have been included at the end of the article. Anomalies affecting the pulmonary parenchyma, its arterial supply, and venous drainage are thus discussed.

Contrast-enhanced three-dimensional MR angiography of the pulmonary vascular tree

Contrast-enhanced three-dimensional MR angiography has evolved into a promising technique in the study of the pulmonary vasculature. Both congenital and acquired entities can be now morphologically demonstrated in a non-invasive manner obviating the need for conventional pulmonary angiography. Due to spatial resolution limitations, however, it is still premature to routinely apply the method in the detection of small subsegmental emboli, in cases of suspected pulmonary embolism, and further technical developments will be required. In this paper we present a spectrum of congenital and acquired disorders affecting the pulmonary vascular tree as demonstrated with contrast-enhanced three-dimensional MR angiography.

Congenital masses of the lung: prenatal and postnatal imaging evaluation

Congenital masses of the lung are a spectrum of interrelated abnormalities that includes congenital lobar overinflation, bronchogenic cyst, congenital cystic adenomatoid malformation (CCAM) and sequestration. The prenatal and postnatal imaging features of these lesions are reviewed, emphasizing the importance of serial prenatal sonograms and postnatal imaging studies, including radiography and computed tomography. Masses that become inconspicuous, or disappear on serial prenatal sonograms are discussed, as well as the importance of postnatal imaging studies in the evaluation of these lesions. Finally, the management of congenital masses of the lung is reviewed, emphasizing the importance of imaging studies in the preoperative evaluation.

Bronchial diseases and lung aeration in children

Bronchial diseases are common in children, and are usually associated with disturbances of aeration. This article briefly summarizes the embryological development and respiratory physiology pertinent to pediatric bronchial diseases. Current diagnostic imaging tools are discussed, with an emphasis on CT, which can demonstrate bronchial pathology such as bronchial obstruction and bronchiectasis in larger bronchi, as well as indirectly show the peripheral physiologic consequences of bronchial disease, such as alterations in aeration. Computed tomography measurements of lung attenuation may aid in diagnosis in problematic cases. Diseases that affect the pediatric airways at different ages are reviewed. Knowledge of these entities is important for accurate interpretation of imaging studies.

Current concepts on imaging of thoracic vascular abnormalities

Pediatric thoracic vascular abnormalities include many anatomic variants and pathologic conditions. Although some vascular variants are inconsequential and are discovered incidentally on imaging studies, several anomalies have profound effects on the airway and pulmonary parenchyma. Imaging plays a key role in evaluating the chest and its vasculature. The chest radiograph is usually the first screening study performed during the course of evaluation for a vascular abnormality. Cross-sectional imaging with CT and magnetic resonance imaging provides precise anatomic information and has in most cases replaced invasive diagnostic angiographic procedures. We describe common thoracic vascular abnormalities that occur in children and the imaging techniques currently used in their evaluation.

An approach to the asymmetric neonatal chest radiograph

Conditions causing respiratory distress in the neonate, which may require surgery or an interventional procedure, typically have asymmetric radiographic findings. The findings are conveniently categorized from the plain radiographs as those producing a large lucent-appearing hemithorax, those producing a large cystic-appearing hemithorax, and those producing a large opaque-appearing hemithorax. Additional imaging with ultrasound, CT, MR imaging, or fluoroscopy can be planned based on the initial radiographic appearance.

Scimitar syndrome with pulmonary arteriovenous fistulas

Right abnormal pulmonary venous return into the inferior vena cava associated with abnormal fissure, dextrocardia, and systemic arterial supply of a variable degree, are the characteristics of the scimitar syndrome. We report on a patient in whom this rare syndrome was associated with pulmonary arteriovenous fistulas within the involved lung.

Intralobar pulmonary sequestration and mediastinal bronchogenic cyst

A patient with a bronchogenic cyst and intralobar pulmonary sequestration is presented. Chest radiography showed a posterior mediastinal mass and a computed tomographic scan of the chest revealed, in addition, an abnormality suggestive of pulmonary sequestration. This was confirmed by an aortogram. It is important to be aware of the coexistence of these anomalies to make a diagnosis preoperatively.

Scimitar sign with normal pulmonary venous drainage and systemic arterial supply. Scimitar syndrome or bronchopulmonary sequestration?

The classic definition of the scimitar syndrome is a triad of hypoplasia of the right lung with anomalous venous drainage and a systemic arterial supply of a variable degree. We report a case in which a scimitar-shaped anomalous vein was observed on the plain chest radiograph, but subsequently a pulmonary angiogram showed that it drained normally into the left atrium.