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Congenital pulmonary airway malformations (CPAMs) have a range of morphologies with varying cyst sizes and histologic features (types 1 to 3). Evidence suggested they arise secondary to bronchial atresia, however, we recently showed that cases with type 1 and 3 morphology are driven by mosaic KRAS mutations. We hypothesized that 2 distinct mechanisms account for most CPAMs: one subset is secondary to KRAS mosaicism and another is due to bronchial atresia. Cases with type 2 histology, similar to sequestrations, would be related to obstruction and therefore negative for KRAS mutations regardless of cyst size. We sequenced KRAS exon 2 in type 2 CPAMs, cystic intralobar and extralobar sequestrations, and intrapulmonary bronchogenic cysts. All were negative. Most sequestrations had a large airway in the subpleural parenchyma adjacent to the systemic vessel, anatomically confirming bronchial obstruction. We compared morphology to type 1 and 3 CPAMs. On average, type 1 CPAMs had significantly larger cysts, but there remained substantial size overlap between KRAS mutant and wild-type lesions. Features of mucostasis were frequent in sequestrations and type 2 CPAMs, while their cysts were generally simple and round with flat epithelium. Features of cyst architectural and epithelial complexity were more common in type 1 and 3 CPAMs, which rarely showed mucostasis. Similarity in histologic features among cases that are negative for KRAS mutation support the hypothesis that, like sequestrations, the malformation of type 2 CPAMs is related to obstruction during development. A mechanistic approach to classification may improve existing subjective morphologic methods., Competing Interests: Conflicts of Interest and Source of Funding: Supported by the Society for Pediatric Pathology Young Investigator Grant (J.P.). The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Congenital malformations of the bronchopulmonary airway and related arterial blood supply are a complex group of lesions in which abnormalities of venous drainage and lung parenchyma may coexist. Twenty five cases have been analysed, by a method whereby each anatomical component is separately considered. All 25 patients had abnormalities of the tracheobronchial tree, with no connection to the abnormal segment in nine cases. The aberrant arterial blood supply was single in 16 cases and multiple in nine cases, one patient from the latter group having a mixed pulmonary and systemic arterial supply to a part of the abnormal segment. Seventeen patients had anomalous venous drainage. In nine of these the vein or veins (they were multiple in four cases) drained the major part or the whole of the lung, whereas the aberrant arterial supply was limited to the right lower zone--that is, mismatched anomalous venous drainage. Abnormalities of lung parenchyma included changes within the lesion (for example, cysts, foregut inclusions) and associated abnormalities of surrounding lung (for example, hypoplasia, abnormal lobation). This information, together with the clinical features and haemodynamic data, was found to be essential for decisions on appropriate management. Patients presenting in infancy with haemodynamic disturbance continue to present major management problems (50% mortality), particularly if there are associated congenital heart defects. The role of aberrant systemic artery occlusion or ligation as a first stage procedure is well established in patients with haemodynamic abnormalities. There may be a place for this procedure in selected patients who have no haemodynamic disturbance at presentation.

The pulmonary sequestration spectrum and related congenital lung anomalies present an extremely complex and varied group of bronchopulmonary-vascular malformations. Previous attempts at nomenclature and classification have proved inadequate. In this article we present a classification of the newly named pulmonary malinosculation spectrum, which includes all congenital lung anomalies where there is abnormal connection (that is, malinosculation) of one or more of the four major components of lung tissue--namely, tracheobronchial airway, lung parenchyma, arterial supply, and venous drainage, which in various combinations make up these lesions. We feel that this simple descriptive approach will improve our understanding and management of these complicated lesions and this is supported by the clinical experience we report in the next article.

Objective: Rare disease Background: Isolated systemic arterial supply to normal (unsequestered) lung (ISSNL) without associated pulmonary malformation is rare, and lies towards the milder end of the spectrum of congenital lung abnormalities. Aneurysmal dilatation of the anomalous artery is an infrequent complication, with only 5 published cases thus far. Case Report: We present the case of a 61-year-old man whose screening chest radiograph showed a retrocardiac mass. Further evaluation with axial imaging demonstrated an ISSNL, complicated by aneurysmal dilatation. The genesis of this condition has been postulated to be due to persistence of primitive aortic branches to the developing lung bud. Initially reported in 1777, this entity is now more accurately classified within the spectrum of pulmonary and bronchovascular abnormalities, with refinement of the latter. The origin of an aberrant artery from the aorta implies that a higher-pressure systemic circulation is being shunted into a lower-pressure pulmonary circulation. While these supplying arteries are known to be large, aneurysmal dilation is exceptionally rare. Here, we review the cases published in the literature and present a case of our own. We aim to describe its pathogenesis, and touch on the classification systems and management. Conclusions: ISSNL is usually first suspected on a screening chest radiograph, as many patients are asymptomatic. Based on contrast-enhanced axial imaging, the diagnosis can be established non-invasively. Definitive management includes surgical and endovascular techniques. [ABSTRACT FROM AUTHOR]

Background Bronchopulmonary sequestration (BPS) and congenital cystic adenomatoid malformation (CCAM) represent rare hamartomatous abnormalities of the lung. Dysregulation of cytokines that influence pulmonary vasculogenesis and epithelial growth, both known to be altered in BPS and CCAM, may play a role in their pathogenesis. Objective We hypothesized that expression of vascular endothelial growth factor (VEGF) or its receptors might be altered in CCAM and BPS, possibly distinguishing CCAM from BPS, or from controls. Methods Lung biopsy specimens obtained from infants who had undergone surgery for BPS (n = 4) or CCAM (n = 5) within the first month of life and normal lung autopsy samples (n = 4) serving as controls were investigated immunohistochemically for the protein expression levels of VEGF and its corresponding receptors. Results VEGF, vascular endothelial growth factor receptor 1 (VEGFR1), vascular endothelial growth factor receptor 2 (VEGFR2), and vascular endothelial growth factor receptor 3 (VEGFR3) staining was detected in CCAM and BPS specimens, as well as in control samples. VEGFR2 expression increased from controls to CCAM and from CCAM to BPS, the difference between controls and BPS being significant. The expression of VEGF, VEGFR1, and VEGFR3 was similar among the three groups. Consistent with a possible involvement of VEGFR2 in altered vasculogenesis-bronchiogenesis interaction, its expression was predominantly found in bronchial but not alveolar regions. Conclusions The data suggest a possible role of VEGF-VEGFR2 interaction in the pathogenesis of congenital bronchopulmonary cysticmalformations. However, VEGFR2 does not represent a suitable histochemical marker to distinguish between BPS and CCAM. [ABSTRACT FROM AUTHOR]

Bronchopulmonary sequestration is a lung malformation characterized by nonfunctioning lung tissue without primary communication with the tracheobronchial tree. Intrauterine complications such as mediastinal shift, pleural effusion or fetal hydrothorax can be present. We present the case of a newborn with bilateral intralobar pulmonary sequestration. Prenatal ultrasonography in a primigravida at 20 weeks of gestation revealed echogenic masses in the right fetal hemithorax with mediastinal shift towards the left side. Serial ultrasound confirmed persistence of the lesion with otherwise appropriate fetal development. Delivery was uneventful and physical examination revealed an isolated intermittent tachypnea. Chest CT scan and CT angiography showed a bilateral intrathoracic lesion with arterial supply from the aorta. Baby lung function testing suggested possible multiple functional compartments. Right and left thoracotomy was performed at the age of 7 months. A bilateral intralobar sequestration with vascularisation from the aorta was resected. Pathological and histological examination of the resected tissue confirmed the surgical diagnosis. At the age of 24 months, the child was doing well without pulmonary complications. Bilateral pulmonary sequestration requires intensive prenatal and postnatal surveillance. Though given the fact of a bilateral pulmonary sequestration, postnatal outcome showed similar favourable characteristics to an unilateral presentation. Baby lung function testing could provide additional information for optimal postnatal management and timing of surgical intervention. [ABSTRACT FROM AUTHOR]

Congenital cystic lung disease comprises a broad spectrum of rare but clinically significant developmental abnormalities, including congenital pulmonary adenomatoid malformations, bronchopulmonary sequestrations, bronchogenic cysts, and congenital lobar emphysema that result from perturbations in lung and airway embryogenesis. As congenital lung lesions are now more commonly recognized antenatally, mothers require accurate prenatal counseling and appropriate perinatal management. In light of long-term complications of infection and malignancy, there is growing consensus that infants with asymptomatic lesions should undergo elective excision of congenital pulmonary adenomatoid malformation (CPAM) or bronchopulmonary sequestration (BPS). This review will focus on advancements and current practice in the diagnosis and management of CPAM and BPS, identifying aspects of the literature that are confusing or controversial. Although our knowledge and pre- and postnatal management of lung lesions will continue to evolve and improve, there is a compelling need for a unified clinical and pathological classification system that creates a common platform for discussion, clinical management, and research. [ABSTRACT FROM AUTHOR]

Bronchopulmonary foregut malformations (BPFM) are a heterogeneous group of pulmonary developmental anomalies that present at varying ages and with overlapping symptoms, signs and radiology. This article discusses the embryology of these lesions with reference to possible common origins and the link between aetiology and radiological appearance. The radiology of each lesion, both antenatally and postnatally, is described and illustrated. A number of quandaries exist in the prediction of prognosis and subsequent treatment of BPFM. We discuss the radiological features that may help to elucidate an individual prognosis and aid in the planning of treatment. The treatment options available for BPFM are briefly discussed. Finally, the link between BPFM, in particular cystic adenomatoid malformations and malignancy, is discussed. We aim to provide a comprehensive overview of the embryology, radiology, prognosis and treatment highlighting contentious issues of BPFM. [ABSTRACT FROM AUTHOR]

Pulmonary sequestration and mediastinal bronchogenic cysts are rare but well known to thoracic surgeons. However, their association is exceptional. We report such a case in a young adult. The common origin of these 2 malformations is discussed. [ABSTRACT FROM AUTHOR]