Congenital masses of the lung: prenatal and postnatal imaging evaluation

Clinical features of atypical solid-type congenital pulmonary airway malformation (CPAM) type 1

INTRODUCTION

Type 1 congenital pulmonary airway malformation (CPAM) is characterized by large, dilated cysts that rapidly expand due to aeration immediately after birth, often necessitating surgical resection. In atypical cases of CPAM type 1, fetal T2-weighted magnetic resonance imaging (MRI) reveals a low-intensity solid lung mass containing multiple irregular T2 high-intensity areas.

METHODS

Data were retrospectively collected for infants with atypical CPAM type 1 born at our hospital between March 2002 and December 2022.

RESULTS

Four infants were identified, all presenting with a low-intensity solid lung mass on T2-weighted fetal MRI and requiring respiratory support after birth. Chest X-rays showed reduced aeration within the mass. Three infants with CPAM volume ratios (CVRs) ≥1.6 underwent emergency surgery on day 1 or 2 due to respiratory failure, while the fourth infant had elective surgery on day 9. Histological examination revealed small CPAM type 1 cysts (inner diameter [I.D.] 1-10 mm), lined by ciliated columnar epithelium and surrounded by a solid component composed of proliferative mucous cells and smaller cysts (I.D. 0.1-0.6 mm), lined by ciliated low-columnar or cuboidal epithelium resembling CPAM type 2 cysts.

CONCLUSION

We managed four cases of solid-type CPAM type 1 with consistent findings on fetal MRI, chest X-ray, and histology. Larger CVRs were associated with the need for early neonatal surgery. Given the volumetric effect on surrounding lung tissue, early surgical resection may be required for large lesions.

Congenital lung lesions: a radiographic pattern approach

Congenital lung malformations represent a spectrum of abnormalities that can overlap in imaging appearance and frequently coexist in the same child. Imaging diagnosis in the neonatal period can be challenging; however, the recognition of several archetypal radiographic patterns can aid in narrowing the differential diagnosis. Major radiographic archetypes include (1) hyperlucent lung, (2) pulmonary cysts, (3) focal opacity and (4) normal radiograph. Here we review the multimodality imaging appearances of the most commonly seen congenital lung malformations, categorized by their primary imaging archetypes. Along with the congenital lung malformations, we present several important imaging mimickers.

Elevated tumor markers in a benign lung disease

BACKGROUND

This study aimed to determine the underlying pathophysiologic mechanism of elevated carbohydrate antigen 19-9 (CA19-9) in pulmonary sequestration (PS) patients.

MATERIALS AND METHODS

Four pulmonary sequestration patients, 12 pneumonia patients and 12 healthy adult volunteers were prospectively studied. Specimens from another 34 pulmonary sequestration patients were retrospectively analyzed. Serum CA19-9 levels of 4 patients were tested before and 1 week, 1 month and 3 months after surgery. The CA19-9 levels of 12 pneumonia patients and 12 healthy adult volunteers were tested as controls. The expression and localization of CA19-9 in diseased lesions and corresponding normal lung tissues were analyzed by Immunohistochemical (IHC). Hematoxylin-eosin (HE) staining was performed to observe the pathological changes in pulmonary sequestration tissues.

RESULTS

Serum CA19-9 levels were significantly higher in the 4 patients (797.3 ± 316 IU/ml) than in the pneumonia patients (10.07 ± 5.01 IU/ml) and healthy volunteers (9.85 ± 4.12 IU/ml). In addition, serum CA19-9 levels decreased dramatically after the focus was removed. Positive staining of CA19-9 was found in 70% (24/34) of pulmonary sequestration tissues, and CA19-9 was mainly expressed in the bronchial mucus. In the 4 diseased lesions, deformed alveolar structure and inflammatory cell infiltration were observed, and the degree of damage was positively correlated with serum CA19-9 levels.

CONCLUSIONS

CA19-9 could be generated by abnormal columnar epithelia in pulmonary sequestration tissues and was transported into circulation after alveoli damage. CA19-9 could serve as an adjuvant diagnostic marker in pulmonary sequestration.

Fluid-filled Cystic Lesions of the Lungs

A pulmonary cyst usually refers to an air-filled space with a smooth, thin wall. Fluid-filled cystic lesions of the lungs include a range of etiologies such as true cysts, congenital malformations, infections, and benign and malignant neoplasms. With relatively little solid component, these lesions often have similar imaging appearances to one another. This article focuses on key imaging features and clinical characteristics that can be used to narrow the differential diagnosis.

Current operative management of congenital lobar emphysema in children: A report from the Midwest Pediatric Surgery Consortium

PURPOSE

The purpose of this study was to evaluate the clinical presentation and operative outcomes of patients with congenital lobar emphysema (CLE) within a large multicenter research consortium.

METHODS

After central reliance IRB-approval, a retrospective cohort study was performed on all operatively managed lung malformations at eleven participating children's hospitals (2009-2015).

RESULTS

Fifty-three (10.5%) children with pathology-confirmed CLE were identified among 506 lung malformations. A lung mass was detected prenatally in 13 (24.5%) compared to 331 (73.1%) in non-CLE cases (p < 0.0001). Thirty-two (60.4%) CLE patients presented with respiratory symptoms at birth compared to 102 (22.7%) in non-CLE (p < 0.0001). The most common locations for CLE were the left upper (n = 24, 45.3%), right middle (n = 16, 30.2%), and right upper (n = 10, 18.9%) lobes. Eighteen (34.0%) had resection as neonates, 30 (56.6%) had surgery at 1-12 months of age, and five (9.4%) had resections after 12 months. Six (11.3%) underwent thoracoscopic excision. Median hospital length of stay was 5.0 days (interquartile range, 4.0-13.0).

CONCLUSIONS

Among lung malformations, CLE is associated with several unique features, including a low prenatal detection rate, a predilection for the upper/middle lobes, and infrequent utilization of thoracoscopy. Although respiratory distress at birth is common, CLE often presents clinically in a delayed and more insidious fashion.

LEVEL OF EVIDENCE

Level III.

Congenital Lung Malformations: Unresolved Issues and Unanswered Questions

Advances in prenatal and postnatal diagnosis, perioperative management, and postoperative care have dramatically increased the number of scientific reports on congenital thoracic malformations (CTM). Nearly all CTM are detected prior to birth, generally by antenatal ultrasound. After delivery, most infants do well and remain asymptomatic for a long time. However, complications may occur beyond infancy, including in adolescence and adulthood. Prenatal diagnosis is sometimes missed and detection may occur later, either by chance or because of unexplained recurrent or persistent respiratory symptoms or signs, with difficult implications for family counseling and substantial delay in surgical planning. Although landmark studies have been published, postnatal management of asymptomatic children is still controversial and needs a resolution. Our aim is to provide a focused overview on a number of unresolved issues arising from the lack of an evidence-based consensus on the management of patients with CTM. We summarized findings from current literature, with a particular emphasis on the vigorous controversies on the type and timing of diagnostic procedures, treatments and the still obscure relationship between CTM and malignancies, a matter of great concern for both families and physicians. We also present an algorithm for the assessment and follow-up of CTM detected either in the antenatal or postnatal period. A standardized approach across Europe, based on a multidisciplinary team, is urgently needed for achieving an evidence-based management protocol for CTM.

The Use of Fetal Bronchoscopy in the Diagnosis and Management of a Suspected Obstructive Lung Mass

Etiologies of fetal lung anomalies include congenital pulmonary airway malformation (CPAM), intra- or extralobar pulmonary sequestration, congenital high airway obstruction syndrome (CHAOS), bronchogenic cyst, and bronchial atresia. Fetal tracheobronchoscopy has been reported both as a diagnostic and therapeutic procedure in the setting of severe congenital lung lesions. In this case report, prenatal imaging of a fetus with a large chest mass was suspicious for an obstructive bronchial lesion. The absence of visible normal lung tissue on the right side and mass effect on the left side raised the concern for pulmonary hypoplasia. After antenatal betamethasone and a period observation, hydropic changes developed. Fetal tracheobronchoscopy was then performed in an effort to identify and decompress the suspected obstructive bronchial lesion. Other than release of bronchial debris, no anatomical abnormalities were visualized. However, the right lung lesion and mediastinal shift both decreased after the fetal bronchoscopy. The newborn underwent postnatal resection of a CPAM Type II and is doing well. We hypothesize that fetal tracheobronchoscopy provided the following potential diagnostic and therapeutic benefits: (1) exclusion of an obstructive bronchial lesion; (2) disimpaction of bronchial debris from the saline lavage that we posit may have contributed to the rapid reduction in CPAM size.

Treatment of congenital pulmonary airway malformations: a systematic review from the APSA outcomes and evidence based practice committee

PURPOSE

Variation in management characterizes treatment of infants with a congenital pulmonary airway malformation (CPAM). This review addresses six clinically applicable questions using available evidence to provide recommendations for the treatment of these patients.

METHODS

Questions regarding the management of a pediatric patient with a CPAM were generated. English language articles published between 1960 and 2014 were compiled after searching Medline and OvidSP. The articles were divided by subject area and by the question asked, then reviewed and included if they specifically addressed the proposed question.

RESULTS

1040 articles were identified on initial search. After screening abstracts per eligibility criteria, 130 articles were used to answer the proposed questions. Based on the available literature, resection of an asymptomatic CPAM is controversial, and when performed is usually completed within the first six months of life. Lobectomy remains the standard resection method for CPAM, and can be performed thoracoscopically or via thoracotomy. There is no consensus regarding a monitoring protocol for observing asymptomatic lesions, although at least one chest computerized tomogram (CT) should be performed postnatally for lesion characterization. An antenatally identified CPAM can be evaluated with MRI if fetal intervention is being considered, but is not required for the fetus with a lesion not at risk for hydrops. Prenatal consultation should be offered for infants with CPAM and encouraged for those infants in whom characteristics indicate risk of hydrops.

CONCLUSIONS

Very few articles provided definitive recommendations for care of the patient with a CPAM and none reported Level I or II evidence. Based on available information, CPAMs are usually resected early in life if at all. A prenatally diagnosed congenital lung lesion should be evaluated postnatally with CT, and prenatal counseling should be undertaken in patients at risk for hydrops.

Prenatal imaging and postnatal presentation, diagnosis and management of congenital lung malformations

PURPOSE OF REVIEW

Congenital lung malformations (CLMs) vary in their clinical presentation and severity. Increases in prenatal diagnosis, observed regression of certain lesions, and prognostic uncertainty are driving an evolution in management.

RECENT FINDINGS

There has been an increase in the early diagnosis of these malformations, a change that is attributable to the routine use of prenatal ultrasound. Although prenatal diagnosis of CLMs using ultrasound and MRI has increased, chest radiography and computed tomography still play important roles in diagnosis. The management of these lesions depends on the type of malformation and symptoms. The treatment of asymptomatic patients with lung malformations is controversial, because the prognosis of these lesions is largely unknown. Proponents of early intervention argue that the complications of CLM, which may include infection, pneumothorax, bleeding and malignant transformation, justify surgery. Advocates of conservative management note that some CLMs disappear postnatally, and that the long-term complication rate following surgery is unknown. There is a need to obtain natural history data regardless of the therapeutic recommendations.

SUMMARY

This article reviews the prenatal radiographic features and postnatal clinical findings of various CLMs and the dilemmas regarding treatment.

Miller-dieker syndrome associated with congenital lobar emphysema

Miller-Dieker syndrome (MDS) is a rare genetic syndrome associated with lissencephaly, developmental delay, and high mortality. We describe a patient who was diagnosed postnatally with both MDS and congenital lobar emphysema. We believe that this is the first reported case of the two conditions presenting in the same patient.

Congenital lung malformations: radiological findings and clues for differential diagnosis

Congenital lung malformations encompass a wide spectrum of conditions with a broadly varying clinical presentation. They are often a source of morbidity in infants and children. Their management depends on the type of malformation and its clinical presentation. Usually, the diagnosis requires an imaging evaluation. Classifications of bronchopulmonary malformations have undergone significant revision in recent years and several theories have attempted to explain their confusing pathogenesis. There are considerable degrees of overlapping and hybrid conditions are common, with interrelated malformations showing various radiologic and pathologic features. Attending to the pathophysiological mechanisms and structures involved, lung malformations can be divided into three categories: bronchopulmonary anomalies, combined lung and vascular abnormalities, and vascular anomalies. The purpose of this article is to review the current imaging techniques for evaluating lung malformations in pediatric patients and their characteristic imaging findings. Moreover, this review discusses a useful classification and offers some clues to facilitate the differential diagnosis.

Imaging of fetal chest masses

Prenatal imaging with high-resolution US and rapid acquisition MRI plays a key role in the accurate diagnosis of congenital chest masses. Imaging has enhanced our understanding of the natural history of fetal lung masses, allowing for accurate prediction of outcome, parental counseling, and planning of pregnancy and newborn management. This paper will focus on congenital bronchopulmonary malformations, which account for the vast majority of primary lung masses in the fetus. In addition, anomalies that mimic masses and less common causes of lung masses will be discussed.

Prenatal interventions for fetal lung lesions

The widespread availability of high resolution ultrasound equipment and almost universal routine anatomy scanning in all pregnant women in the developed world has lead to increased detection of abnormalities in the fetal thorax. Already in the 1980s, large pleural effusions and significant macrocystic lesions in the fetus were easily detected on ultrasound. However, smaller lung tumours were often missed. Nowadays, fetal medicine centres receive many referrals for evaluation of fetal lung lesions, of which the most common are congenital cystic adenomatoid malformation and bronchopulmonary sequestration. Almost invariably, both the parents and the referring physicians experience anxiety after detection of large lung masses in the fetus. However, the vast majority of the currently detected fetal lung lesions have an excellent prognosis without the need for prenatal intervention. In the small group of fetuses in which the prognosis is poor, almost exclusively those with concomitant fetal hydrops and cardiac failure, several options for fetal therapy exist, often with a more than 50% survival rate. Indications, techniques, complications and outcomes of these interventions will be described in this review.

Fetal cystic lung lesions: evaluation with magnetic resonance imaging

OBJECTIVES

To investigate the contribution of magnetic resonance imaging (MRI) to the diagnosis of fetal cystic lung lesions found on routine prenatal ultrasound (US).

STUDY DESIGN

Experienced radiologists retrospectively reviewed 34 fetal MRI studies performed in 20 fetuses (from 20 to 35 gestational weeks; including 14 repeat studies 10 weeks after the initial MRI), focusing on shape, signal characteristics, feeding artery, volume change, and location of the cystic lesions. Diagnoses were confirmed after birth by postnatal multidetector computed tomography (MDCT) and/or surgery.

RESULTS

Bronchopulmonary sequestration (BPS) in the second trimester appeared as a well-defined, homogeneous, hyperintense mass (pure BPS) in eight cases or as a lobulated, inhomogeneous hyperintense mass (BPS mixed with congenital cystic adenomatoid malformation (CCAM)) in three cases. The feeding artery was visible in all 11 cases in the initial MRI, and regression of the mass was seen in 7 cases. As the mass regressed in the third trimester, the signal intensity decreased, becoming inhomogeneous, and the margins became lobulated. The mean initial ratio of the volume of the BPS lesion to the ipsilateral lung in lesions with partial regression was 82%; the mean initial ratio in lesions with nearly complete regression was 61%. CCAM (6) cases also appeared as a hyperintense lobulated mass, and as the lesions regressed, they decreased in size and signal intensity. As with BPS, the larger the lesion on initial MRI, the less likely it was to regress completely. Congenital lobar fluid overload in three cases appeared as a hyperintense, homogeneous lobe with stretched hilar vessels.

CONCLUSION

Prenatal MRI is useful as a diagnostic tool complementary to US for evaluating fetal cystic lung lesions. Smaller lung lesions (<60%) may regress completely.

Management of congenital cystic adenomatoid malformation and bronchopulmonary sequestration in newborns

BACKGROUND

Congenital cystic adenomatoid malformation (CCAM) and bronchopulmonary sequestration (BPS) are major embryonic pulmonary developmental anomalies. Early surgical excision is becoming an increasingly common option. We investigated the clinical features and management of patients with CCAM and BPS at the National Taiwan University Hospital.

METHODS

We conducted a retrospective review of neonates diagnosed with CCAM and/or BPS at the Hospital from July 1995 to January 2008. Prenatal examination, postnatal presentation, management and patient outcome were analyzed. We also propose a concise algorithm for the practical management of these conditions.

RESULTS

Sixteen patients were recruited including eight (50%) with CCAM, five (31%) with BPS and three (19%) with mixed-type lesions (CCAM with BPS). Thirteen (81%) patients were diagnosed antenatally at a median gestational age of 20 weeks. Eleven (69%) patients underwent surgical resection before 6 months of age because of respiratory distress or repeated pulmonary infection. There were no surgery-related complications among the seven patients who underwent early surgery within 1 month of age. Five (31%) patients remained asymptomatic and did not undergo surgery. All patients survived with no limitations to daily activity during follow-up periods of 1-8 years.

CONCLUSION

The high proportion of mixed-type lesions suggests that CCAM and BPS may share the same developmental ancestry. Early surgical resection within 1 month of age is safe in symptomatic patients.

Congenital cystic adenomatoid malformation of lung type 1

Congenital cystic adenomatoid malformation, a rare developmental, hamartomatous abnormality of the lung, usually is unilateral, is localized, and presents in early infancy. Delayed occurrence in older children and multilobar involvement are rare. We describe a case of congenital cystic adenomatoid malformation type 1 with multilobar involvement, associated emphysema, and coexistent tracheobronchopathia osteochondroplastica in an adolescent girl for whom the correct diagnosis was achieved only on histologic examination. The importance of an accurate diagnosis of this entity enables proper subtyping, management to minimize the risk of infections and malignancy, and exclusion of associated malformations.

Imaging of the pediatric airway

Airway compromise can be fixed, dynamic (with varying degrees of collapse during the respiratory cycle), or exhibit both components. The location of the abnormality can be classified as extrinsic (located outside but exerting mass effect on the airway) or intrinsic (intramural and/or intraluminal). The etiologies of airway compromise are categorized as: congenital, infectious, inflammatory, traumatic, vascular, or neoplastic (1). The role of imaging of the airway is to determine the presence, nature and anatomic level of airway compromise, categorize it as intrinsic or extrinsic, provide a differential diagnosis, and guide further imaging or management (1). The differential diagnosis of a lesion takes into account the patient's age and gender, location of the lesion, clinical presentation, and imaging appearance.

Fetal pleural effusions

The clinical course of primary fetal hydrothorax is unpredictable. Whereas smaller unilateral effusions might remain stable or even regress, this is rarely the case with larger collections. Bilateral effusions, hydrops, preterm delivery and the lack of antenatal therapy are all associated with poor outcome. Once structural and chromosomal anomalies have been excluded, optimal management depends on gestational age, rate of progression, the development of hydrops and associated maternal symptoms. For very large effusions with mediastinal shift, hydrops and/or hydramnios, or when there is rapid enlargement of the effusion, fetal intervention is warranted. Survival can be maximized by pleuroamniotic shunting, which can reverse hydrops and hydramnios and prevent pulmonary hypoplasia. Pleuroamniotic shunting can also be used for the treatment of other large cystic lung lesions, such as a macrocystic congenital cystic adenomatoid malformation or bronchopulmonary sequestration, especially when associated with hydrops.

Type I pleuropulmonary blastoma: pathology and biology study of 51 cases from the international pleuropulmonary blastoma registry

Pleuropulmonary blastoma (PPB) is a malignant neoplasm of the lung that presents in early childhood. The early form of the disease, cystic type I PPB, can be clinically and pathologically deceptive because of its resemblance to some developmental lung cysts. This study reviews 51 cases of type I PPB and 6 lung cysts from relatives of children with PPB. Type I PPB is a delicate multilocular cyst with variable numbers of primitive mesenchymal cells beneath a benign epithelial surface. Rhabdomyoblasts and cartilage nodules are seen in 49% and 40% of cases, respectively. Tumors in the youngest subset of patients, from birth to 2 months of age, are more uniform in composition and cellularity compared with those in older groups. Early tumors have a subtle transition between normal developing lung and tumor, showing bland interstitial mesenchymal cells uniformly expanding the alveolar septa. Presumed regressive changes including cyst wall necrosis are common. This phenomenon may explain the variable and sometimes sparse tumor cellularity seen in some type I PPBs. On a biologic level, this process supports the concept that not all type I PPBs are fated to progress to a type II or III PPB. Factors that control the balance between progression and regression may be important in predicting tumor behavior and determining which patients will benefit from adjuvant chemotherapy. In the meantime, recognition of this lesion as a neoplasm with malignant potential rather than a developmental cystic malformation is vital so the child can receive complete excision and appropriate follow-up care.

Multimodality imaging of tracheobronchial disorders in children

The trachea and bronchial airways in children are subject to compromise by a number of extrinsic and intrinsic conditions, including congenital, inflammatory, infectious, traumatic, and neoplastic processes. Stridor, wheezing, and respiratory distress are the most common indications for imaging of the airway in children. Frontal and lateral chest and/or neck radiography constitute the initial investigations of choice in most cases. Options for additional imaging include airway fluoroscopy, contrast esophagography, computed tomography (CT), and magnetic resonance (MR) imaging. Advanced imaging techniques such as dynamic airway CT, CT angiography, MR angiography, and cine MR imaging are valuable for providing relevant vascular and functional information in certain settings. Postprocessing techniques such as multiplanar reformatting, volume rendering, and virtual bronchoscopy assist in surgical planning by providing a better representation of three-dimensional anatomy. A systematic approach to imaging the airway based on clinical symptoms and signs is essential for the prompt, safe, and accurate diagnosis of tracheobronchial disorders in children.

Intralobar pulmonary sequestration associated with a congenital pulmonary airway malformation type II

Intralobar pulmonary sequestration (ILPS) is a rare congenital malformation of the lung. It is described as a segment of lung parenchyma with normal pleura and systemic blood supply and it has poor communication with the tracheobronchial tree. Patients usually present in later childhood or adulthood with a history of recurrent pneumonias. The malformation is rarely associated with other congenital anomalies such as a congenital pulmonary airway malformation (CPAM). A CPAM is a congenital cystic lesion of the lung that presents usually in the newborn period as respiratory distress. We describe the case of a 2-month-old female who presented to the local emergency room with the initial diagnosis of pneumonia, surgical diagnosis of ILPS, and a final pathological diagnosis of ILPS with an associated CPAM.

Congenital Pulmonary Airway Malformation

OBJECTIVES

Congenital pulmonary airway malformation (CPAM) is classified into 5 subtypes (types 0 to 4). We attempted to correlate computed tomography (CT) findings with those of pathologic examination and evaluated the predictability of the CPAM subtype.

SUBJECTS AND METHODS

We retrospectively reviewed CT findings in 13 pathologically proven cases of CPAM seen between 1981 and 2005. Patient's age ranged from 4 days to 5 years and 10 months. Six were boys and 7 were girls. According to CT findings, lesions with a cyst larger than 2.5 cm, lesions with cysts 2.5 cm or less and solid lesions were classified into groups A, B, and C, respectively. We assumed that Stocker's types 1 and 4, type 2, and types 0 and 3 would correspond to CT groups A, B, and C, respectively. Then, we assessed whether this assumption is correct or not.

RESULTS

Eight, 3, and 2 cases were diagnosed as groups A, B, and C, respectively. All of the 8 cases diagnosed as group A were Stocker's type 1. One of the 3 cases diagnosed as group B was type 2, but the remaining 2 were type 1 and type 4, respectively. One of the 2 cases diagnosed as group C was type 3 but the other was type 2.

CONCLUSIONS

Lesions with the largest cyst being larger than 2.5 cm was type 1. It seemed, however, difficult to distinguish among types 1, 2, and 4 when they consisted of small cystic components and between types 2 and 3 when they appeared as a solid lesion.

Management of congenital lung lesions

Antenatally diagnosed lung lesions are most commonly congenital cystic adenomatiod malformations (CCAMs) or bronchopulmonary sequestrations (BPS). Congenital lobar emphysema and bronchogenic cysts occur rarely. CCAMs and BPS can only be truly distinguished on histopathological assessment. CCAMs can be defined using either Stocker's histological classification, or the clinically more useful 'macrocystic' and 'microcystic' subtypes introduced by Adzick. Adverse pathophysiological effects (e.g. lung hypoplasia, mediastinal shift, caval obstruction and hydrops) can occur with those of larger volume in the developing fetus and are associated with a poor outcome ( approximately 5%). In centres with appropriate expertise, antenatal intervention (e.g. thoracoamniotic shunting) should be considered for such cases. In the postnatal period, early radiological evaluation (e.g. CT scan) is essential as many cases which apparently 'regress' antenatally are still detectable and may be a cause of later morbidity. Early surgical excision is required for symptomatic cases and should also be considered for asymptomatic antenatally diagnosed lesions, because of the risks of later infection and the possibility of malignant transformation. An excellent outcome following surgery can be expected.

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.

Asymptomatic congenital lung malformations

Congenital lung malformations are often discovered incidentally on routine prenatal sonography or postnatal imaging. Lesions such as congenital cystic adenomatoid malformations (CCAM), sequestrations, bronchogenic cysts and congenital lobar emphysema may be asymptomatic at birth or at the time of discovery later in life. Some authors advocate simple observation because of the lack of data on the incidence of long-term complications. However, there are very few described cases where CCAM and intralobar sequestration have remained asymptomatic throughout life; complications eventually develop in virtually all patients. The most common complication is pneumonia, which may respond poorly to medical treatment. Other complications include the development of malignancies (carcinomas and pleuropulmonary blastomas), pneumothorax and hemoptysis or hemothorax. Since lung resection will be required sooner or later for CCAM, intralobar sequestration and intrapulmonary bronchogenic cysts it is best not to wait for complications to occur. For patients diagnosed prenatally, we recommend surgery at 3 to 6 months of life at the latest, so that compensatory lung growth can occur. At this age the postoperative course is usually smooth and long-term follow-up has shown normal respiratory function. Mediastinal bronchogenic cysts also tend to become symptomatic and elective resection is recommended. On the other hand, asymptomatic congenital lobar emphysema may regress spontaneously and observation is warranted. The management of small noncommunicating extralobar sequestrations is more controversial; it is known that these lesions can remain asymptomatic throughout life but complications may develop and they are sometimes difficult to differentiate from neuroblastoma.

Prenatal diagnosis of pulmonary sequestration using three-dimensional power Doppler ultrasound

OBJECTIVE

To investigate the contribution of three-dimensional power Doppler ultrasound to the prenatal diagnosis of pulmonary sequestration.

METHODS

Prenatal three-dimensional power Doppler ultrasound was used to screen for an abnormal pulmonary blood supply in eight fetuses with hyperechogenic lung lesions and to image the pulmonary blood supply in 50 normal controls. A comparison was made with postnatal findings.

RESULTS

Postnatally the eight pulmonary lesions were found to be an isolated pulmonary sequestration (n = 3), a microcystic congenital adenomatoid malformation (n = 4), and a mixed (macrocystic and microcystic) congenital adenomatoid malformation (n = 1). Prenatal three-dimensional power Doppler ultrasound demonstrated an abnormal blood supply in all cases of pulmonary sequestration and in none of the other cases. Among the three cases that turned out to be pulmonary sequestrations, conventional two-dimensional ultrasound failed to identify the feeding vessel in one case and identified it at a later stage of gestation than did three-dimensional power Doppler in the other two.

CONCLUSION

Prenatal three-dimensional power Doppler ultrasound may be useful in identifying the feeding vessel and thus establishing the diagnosis of pulmonary sequestration in the presence of a hyperechogenic pulmonary lesion, allowing its differentiation from congenital cystic adenomatoid malformation.

Volume contrast imaging: A new approach to identify fetal thoracic structures

OBJECTIVE

To assess the potential of volume contrast imaging for evaluation of fetal intrathoracic structures.

METHODS

Volume contrast imaging is a new ultrasonographic method that increases the contrast between tissues. It consists of a 5- to 10-mm-thick slice-shaped volume image projected on a 2-dimensional screen. The rendering process applied on the slice smoothens the speckle pattern of the image by filling up the gaps with tissue information from the adjacent layers. To evaluate the potential of volume contrast imaging for enhancing the contrast between fetal lungs and surrounding tissues, we compared the ability of volume contrast imaging and conventional ultrasonography to image the fetal thymus in 50 controls. We also applied volume contrast imaging to prenatal imaging of 6 thoracic abnormalities (2 left congenital diaphragmatic hernias, 1 right diaphragmatic hernia, 2 congenital adenomatoid lung malformations, and 1 lung sequestration).

RESULTS

In controls, the thymus was identified in all cases by volume contrast imaging and in 42 cases (84%) by conventional 2-dimensional ultrasonography. Clear images of macrocystic and microcystic congenital adenomatoid malformations were obtained by volume contrast imaging, which provided precise contouring of the lesions. In cases with congenital diaphragmatic hernias, volume contrast imaging provided clear images of the limits of the lungs ipsilateral to the hernia.

CONCLUSIONS

Volume contrast imaging may enhance the contrast between fetal lungs and surrounding organs and can be applied to prenatal imaging of intrathoracic structures in cases with thoracic fetal abnormalities.

Intra-abdominal sequestration of the lung and elevated serum levels of CA 19-9: a diagnostic pitfall

BACKGROUND

Extralobar pulmonary sequestration is an uncommon congenital abnormality that is rarely diagnosed after the age of 40 years. We describe a 64-year-old woman with an intra-abdominal sequestration of the lung and elevated carbohydrate antigen (CA) 19-9 serum levels.

CASE OUTLINE

On abdominal ultrasound a semi-solid cystic tumour was demonstrated that showed tight connection to the tail of the pancreas according to computed tomography. Cytological examination of the percutaneous biopsy did not lead to a definitive diagnosis. CA 19-9 serum levels were repeatedly elevated >250 IU/ml. With a tentative diagnosis of a tumour of the tail of pancreas the semi-solid cystic mass was resected. Frozen section histology suggested the diagnosis of pulmonary sequestration, which was confirmed by definitive histological examination. Immunohistochemical staining of the specimen with a specific monoclonal antibody against CA 19-9 showed strong immunoreactivity. Three months later the elevated CA 19-9 serum levels returned to normal.

DISCUSSION

Elevated CA 19-9 serum levels have been described in benign pulmonary and mediastinal cystic lesions and in one case of extralobar intrathoracic lung sequestration. Although there is evidence that malignancies may arise in congenital lung cysts, CA 19-9 serum levels have not been investigated in such cases. Based on our results elevated serum values of CA 19-9 in combination with a cystic semi-solid mass in the left subphrenic space should include the differential diagnosis of extralobar pulmonary sequestration.

Congenital anomalies of the tracheobronchial tree, lung, and mediastinum: embryology, radiology, and pathology

Congenital anomalies of the chest are an important cause of morbidity in infants, children, and even adults. The evaluation of affected patients frequently requires multiple imaging modalities to diagnose the anomaly and plan surgical correction. The authors analyze and illustrate practical aspects of certain common and uncommon congenital anomalies affecting the tracheobronchial tree, lung, and mediastinum, with emphasis on radiologic manifestations. Other thoracic anomalies such as rib anomalies and vascular rings are discussed when they are associated with anomalies of the tracheobronchial tree. The usefulness of the various imaging modalities in the diagnosis and treatment of these conditions is also evaluated. Specific topics addressed include tracheal conditions such as tracheal stenosis, tracheomalacia, tracheal bronchus, tracheal atresia, and bronchogenic cyst; anomalies of the lung such as lung underdevelopment (agenesis and hypoplasia), scimitar syndrome, congenital cystic adenomatoid malformation, congenital lobar emphysema, and pulmonary sequestration; esophageal anomalies such as esophageal atresia, tracheoesophageal fistula, and esophageal duplications; and vascular rings. The embryologic and pathologic basis of the radiologic findings are discussed in appropriate cases. Differential diagnoses, as well as pitfalls and diagnostic difficulties, are included.

Malformação adenomatóide quística congénita do pulmão ou malformação congénita das vias aéreas pulmonares

The cystic adenomatoid malformation of the lung is an hamartomatous lesion, easily identifiable by its morphology through the application of Stocker's et al (1977) classification (type 1, 2 and 3) and also following the criteria of Yousem, to understand the five types dependent on the level of malformation in the airway and lung. The three morphological types described by Stocker were identified in 6 cases of the archive of the Department of Pathology of Coimbra's University Hospital, studied morphologically by the use of Movat's pentachromic stain and the application of the antibody anti-CK7 and anti-body anti-TTF1. In the three morphological types the elastic alveolar net is absent. The CK7 identifies the epithelial distribution and is useful to evaluate the extension of the inflammatory lesion. The antibody anti-TTF1, apparently absent in type 3 cases, is easily identified in type 1 and 2 cases and overexpressed in inflammatory areas. It seems that the absence of cells identified by the antibody anti-TTF1 prevents overdiagnosing of type 4 in Yousem's classification of congenital pulmonary airway malformation (CPAM).