Extralobar Pulmonary Sequestration in Adrenal Mimicking Neuroblastoma: A Case Report.

Background: Extralobar pulmonary sequestration (ELS) is a malformation composed of bronchopulmonary tissue outside the lungs that is discontinuous from the main tracheobronchial tree. ELS can present as a suprarenal space occupying lesion. Case Report: A 1-day old girl presented with a right supra-adrenal mass, first detected in-utero at 34 weeks. The differential included congenital neuroblastoma, but the urinary VMA was normal. At resection, there was lung tissue composed of dilated and tortuous bronchioles lined by columnar epithelium present in a back- to- back arrangement along with thick-walled vessels, features of an ELS with congenital pulmonary airway malformation type II. Conclusion: ELS enters the differential diagnosis of neonatal suprarenal masses with normal urinary catecholamines, and can have the morphology of a type II congenital pulmonary airway malformation.

Global interpretation of novel alternative splicing events in human congenital pulmonary airway malformations: A pilot study.

Little is known about differentially expressed genes (DEGs) and alternative splicing (AS) landscapes in congenital lung malformations (CLMs). We applied reference-based assembly of sequencing reads from RNA sequencing (RNA-seq) libraries to identify DEGs and AS landscapes in the lesions and normal lung tissue from the most common types of CLMs, including congenital pulmonary airway malformation-Ⅰ (CPAM-Ⅰ), CPAM-Ⅱ, intralobar sequestration (ILS), and ILS with CPAM (ILS-CPAM). We analyzed the expression profiles and related biological functions of AS events (ASEs). We further constructed a co-expression regulatory network between RNA binding protein (RBP) genes and corresponding ASEs to explore the related pathways in the regulated network. Ten DEGs were identified in the four types of CLMs, including eight upregulated genes and two downregulated genes. Additionally, 16 differential ASEs were detected, including the genes MACF1, RFX2, and FBXL4. Gene ontology (GO) enrichment was mainly observed in embryonic visual malformation and apoptotic process, and the KEGG pathway mainly enriched in the PI3K/AKT signaling pathway. We also detected 13 differentially expressed RBPs among 1979 DEGs in CPAM-I, in which ASEs in the MACF1 gene and RBP genes TLR8 and PTRH1 were closely associated. Moreover, we confirmed that the expression levels of PTRH1, NSUN7, and DZIP1L abundantly increased and the expression levels of TLR8, MEF2A, and NIPBL decreased in the CPAM-I lung tissue compared with the controls. It is suggested that ASEs in different types of CLMs is prominently different from normal controls, and ASEs differences occurring in CPAM-I malformation tissue are dramatically different from other types, which demonstrates the complex pathogenesis of CLMs and provides foundations for future studies to elucidate the mechanisms of developing CLMs.

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.

Mucinous adenocarcinoma arising in congenital pulmonary airway malformation: clinicopathological analysis of 37 cases.

AIMS: Mucinous adenocarcinoma arising in congenital pulmonary airway malformation (CPAM) is a rare complication, with little being known about its natural course. The aims of this article are to describe a series of mucinous adenocarcinomas arising from CPAMs, and present their clinicopathological features, genetics, and clinical outcome. METHODS AND RESULTS: Thirty-seven cases were collected within a 34-year period, and the subtype of adenocarcinoma and CPAM, tumour location, stage, growth patterns, molecular data and follow-up were recorded. The cohort comprised CPAM type 1 (n = 33) and CPAM type 2 (n = 4). Morphologically, 34 cases were mucinous adenocarcinomas (21 in situ; 13 invasive), and three were mixed mucinous and non-mucinous adenocarcinoma. Seventeen cases showed purely extracystic (intra-alveolar) adenocarcinoma, 15 were mixed intracystic and extracystic, and five showed purely intracystic proliferation. Genetically, nine of 10 cases tested positive for KRAS mutations, four with exon 2 G12V mutation and five with exon 2 G12D mutation. Residual disease on completion lobectomy was observed in two cases, and three cases recurred 7, 15 and 32 years after the original diagnosis. Two patients died of metastatic invasive mucinous adenocarcinoma. CONCLUSIONS: Most adenocarcinoma that arise in type 1 CPAMs, are purely mucinous, and are early-stage disease. Intracystic proliferation is associated with lepidic growth, an absence of invasion, and indolent behaviour, whereas extracystic proliferation may be associated with more aggressive behaviour and advanced stage. Most cases are cured by lobectomy, and recurrence/residual disease seems to be associated with limited surgery. Long-term follow-up is needed, as recurrence can occur decades later.

Single-cell transcriptome profiling reveals the mechanism of abnormal proliferation of epithelial cells in congenital cystic adenomatoid malformation.

OBJECTIVES: Congenital cystic adenomatoid malformation (CCAM) is the most common congenital pulmonary anomaly with unknown etiology. Here, single-cell RNA sequencing (scRNA-seq) was used to map its cellular landscape and identify the underlying cellular and molecular events related to CCAM. METHODS: This study involved a 4.25 year old patient with grade Ⅱ-Ⅲ CCAM at the Children's Hospital of Fudan University. Samples of lesioned and non-lesioned areas were collected during surgery for scRNA-seq. RESULTS: In total, 19,904 cells were obtained with median UMI counts of 7032 per cell and 1995 median genes per cell. In terms of lesioned and non-lesioned areas, epithelial cells accounted for 27.23% and 17.85%, respectively, while mesenchymal cells accounted for 2.67% and 16.06%, respectively (P < 0.0001). Further clustering of epithelial cells revealed that the fractions of alveolar type 1 cells (AT1, N: 23.65%; L: 49.81%), AT2(N: 2.02%; L: 5.26%), club-1(N: 9.02%; L: 17.57%), club-3(N: 1.18%; L: 4.15%), and basal cells (N: 0.34%; L: 2.93%) were increased in lesioned samples (P < 0.0001). Pseudotime trajectory analysis showed tracks of club-1/basal cells→AT2→club-3→AT1 and club-1,2/basal→AT2. Mast cells (N: 0.63%; L: 2.48%) were also increased in lesioned samples and interactions of CD44 with HBEGF and FGFR2 were detected between mast and epithelial cells. CONCLUSIONS: AT1, AT2, club, and basal cells were increased in CCAM patients, and newly defined club-1/3 and basal cells might be the origin of proliferating AT1 and AT2 cells. Increased mast cells might promote epithelial cell proliferation through interactions of CD44 with HBEGF and FGFR2.

An Incidental Finding of Congenital Pulmonary Airway Malformation Type 3 During a Forensic Autopsy for a Sudden Infant Death: A Case Report With a Brief Literature Review.

ABSTRACT: Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic airway malformation, is a developmental disorder of the lower respiratory tract. It is subdivided into 5 types based on clinical and pathologic features. Type 3, an adenomatoid type of CPAM, is the second rarest form of CPAM, occurring in approximately 5% of all CPAM cases. This article reports an autopsy of a nearly 11-week-old male infant, found unresponsive in bed with his mother. She had fallen asleep after breastfeeding a few hours prior. Although the autopsy and additional technical examinations did not uncover the exact cause of death, CPAM type 3 was eventually identified on histological examination. Taking into account the context of this case, in which accidental asphyxia/neglect could not be ruled out, it is thought that the presence of CPAM might have contributed to the demise of the infant. As CPAM is a rare congenital disorder, the diagnosis could easily be missed. Therefore, this article aims to raise awareness of this diagnosis and points out the clinical and pathologic features of this disorder.

The prenatal ultrasonic character and postnatal follow-up of 227 microcystic and macrocystic congenital cystic adenomatoid malformations.

The objective of our study was to compare microcystic and macrocystic congenital cystic adenomatoid malformation (CCAMs) through prenatal characteristics, perinatal outcome, postnatal management and development after consultation in our prenatal diagnosis centre. We conducted a retrospective cohort study of 227 cases prenatally diagnosed as CCAM in our hospital within three years. One hundred and eighty-one cases continued their pregnancy and 46 pregnancies were terminated. One hundred and fifteen of 227 cases were microcystic and 112 were macrocystic. The prenatal ultrasound characteristics of two types showed no statistically significant differences, despite that CVR of macrocystic CCAMs was mildly greater than microcystic. None of recorded cases received surgical intervention in utero. Compared with healthy foetuses, CCAMs presented with higher percentage of polyhydramnios and male foetuses, larger amount of postpartum blood loss and longer duration of NICU hospitalisation. Compared with 46 legal abortions, continued pregnancy cases had a smaller CVR, less polyhydramnios, cardiac shift and hydrops. One hundred and seventy-nine cases were followed up after birth and 174 babies were asymptomatic. Thirty one cases received successful surgical resection. In conclusion, the prenatally diagnosed CCAMs have a good short-term prognosis and conservative management is a reasonable option in asymptomatic fetuses. Microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management, prenatally and postnatally, could be accepted in selected cases.Impact statementWhat is already known on this subject? Congenital cystic adenomatoid malformation is a well-known developmental abnormality of the lung. The prognosis for most CCAMs is good, but the prenatal and postnatal management remains controversial.What do the results of this study add? This study is one of the largest case cohorts to conclude that microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management is a reasonable option in asymptomatic babies.What are the implications of these findings for clinical practice and/or further research? A comprehensive assessment by an experienced multidisciplinary team is necessary to forbid blinding abortions of CCAMs. Conservative management prenatally and postnatally could be accepted in most asymptomatic cases.

Congenital cystic adenomatoid malformations of the lung: an epithelial transcriptomic approach.

BACKGROUND: The pathophysiology of congenital cystic adenomatoid malformations (CCAM) of the lung remains poorly understood. AIM: This study aimed to identify more precisely the molecular mechanisms limited to a compartment of lung tissue, through a transcriptomic analysis of the epithelium of macrocystic forms. METHODS: Tissue fragments displaying CCAM were obtained during planned surgical resections. Epithelial mRNA was obtained from cystic and normal areas after laser capture microdissection (LCM). Transcriptomic analyses were performed and the results were confirmed by RT-PCR and immunohistochemistry in independent samples. RESULTS: After controlling for RNA quality, we analysed the transcriptomes of six cystic areas and five control areas. In total, 393 transcripts were differentially expressed in the epithelium, between CCAM and control areas. The most highly redundant genes involved in biological functions and signalling pathways differentially expressed between CCAM and control epithelium included TGFB2, TGFBR1, and MAP 2 K1. These genes were considered particularly relevant as they have been implicated in branching morphogenesis. RT-qPCR analysis confirmed in independent samples that TGFBR1 was more strongly expressed in CCAM than in control tissues (p < 0.03). Immunohistochemistry analysis showed TGFBR1 (p = 0.0007) and TGFB2 (p < 0.02) levels to be significantly higher in the epithelium of CCAM than in that of control tissues. CONCLUSIONS: This compartmentalised transcriptomic analysis of the epithelium of macrocystic lung malformations identified a dysregulation of TGFB signalling at the mRNA and protein levels, suggesting a possible role of this pathway in CCAM pathogenesis. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01732185.

Cystic and pseudocystic pulmonary malformations in children: Clinico-pathological correlation.

Pulmonary malformations are rare disorders, with cystic and pseudocystic pulmonary malformations (CPPM) the most frequent, and constitute the first cause of lobectomy in children <1 year of age. Morphological overlap of congenital cystic pulmonary lesions might correspond to a spectrum of lesions in which bronchial atresia is a common etiopathogenetic mechanism. We aimed to report the frequency of CPPM resected in a tertiary-level hospital and to evaluate the degree of agreement between presurgical and anatomopathological diagnoses. We studied 44 surgical pieces with a diagnosis of CPPM received at the Pathology Service from 2009 to 2014, resected from 39 patients, 51.3 % males, with a median age of 16.8 months. Up to 69.2% of the patients had adenomatoid malformation of pulmonary airway (AMPA), with type 2 the most frequent (55.5%). Pulmonary sequestration was present in 15.4% of patients; in two cases the diagnosis was an incidental finding during surgery for the repair of a diaphragmatic hernia. Congenital lobar hyperinflation (CLH) occurred in 7.6% cases. Bronchogenic cyst (BC) was present in 7.6% cases. Presurgical and anatomopathological diagnoses in all patients coincided in 71.8% of cases. Kappa coefficient was 0.56 for global concordance in patients with AMPA, and 0.72, 0.64, 0.37 and 0.33 for CLH, BC, and types 1 and 2 AMPA, respectively. This relatively low interobserver agreement could reflect the low reproducibility of diagnoses used in the current nomenclature. Thus, the new nomenclature must be promoted in order to allow for better reproducibility and greater clinico-pathological concordance. The anatomopathological analysis must include the intentional search for bronchial atresia.

Congenital Pulmonary Airway Malformation - 19-Year Experience from a Tertiary Care Center in India.

Background: Congenital pulmonary airway malformation (CPAM) is a collection of non-hereditary, developmental anomalies. Our aim was to analyze the histological profiles and prevalence of CPAMs diagnosed in our center. Methods: A retrospective study of all CPAMs diagnosed from January 1999 to May 2018 from a general hospital pathology service was performed. Results: There were 79 cystic lesions encountered in fetuses, neonates, and children, 15 of which were CPAMs {5/2372 (0.21%) autopsies and 10/216026 (0.0046%) surgical resections}. The male:female ratio was 1:1.14. Gestational age of antenatal cases ranged from 22 to 32 weeks, postnatal ages ranged from 7 days to 15 years (mean 2.9 years). The cases were right-sided (8/15;53.3%), left-sided (4/15;26.7%) and bilateral (3/15,20%). Seven (46.7%), 4 (26.7%),3 (20%) and 1 (6.7%) were types 1, 2, 3 and 4, respectively. None of the surgical cases had postoperative mortality or morbidity. Conclusions: Prompt recognition and surgical resectability resulted in normal growth and symptom free survival in our postnatally diagnosed patients. Mortality in antenatally diagnosed fetuses remains high (5/11;45%).

Pleuropulmonary Blastoma Developing in a Case of Misinterpreted Congenital Pulmonary Airway Malformation: a Case Report.

BACKGROUND: Pleuropulmonary blastoma (PPB) is a childhood malignancy known to be associated with congenital pulmonary airway malformation (CPAM). CASE REPORT: An 18 months boy presented with respiratory distress. Computed tomography (CT) scans revealed a large right-sided lung mass. Fine needle aspiration cytology (FNAC) showed sheets and clusters of small round to oval cells with scanty cytoplasm. The possibility of PPB was suggested. Trucut biopsy from the mass confirmed the diagnosis of PPB, of at least type II. The child had earlier been diagnosed as CPAM for which he had undergone lobectomy at six months, which on review was diagnosed as PPB I. CONCLUSION: We describe the cytological and histological findings of a case of PPBII/III evolving from a PPB I originally thought to be a CPAM type IV. This supports the theory that PPB I may progress to a more aggressive type II with time, and highlights the importance of the adequately treating the PPB I to prevent this transformation.

Lack of epithelial PPARγ causes cystic adenomatoid malformations in mouse fetal lung.

Peroxisome proliferator-activated receptor-γ (PPARγ) plays an important role in lipid and glucose metabolism. In this study, the function of PPARγ on lung development was investigated. Lung-specific Pparg conditional knockout mice (PpargΔLuEpC) were developed using Cre-Lox system. PpargΔLuEpC mice showed abnormal lung development with enlarged airspaces and followed by increase of apoptotic cells at E14.5 to E18.5. Gene analysis revealed that expression of Pmaip1, a gene related to apoptosis, was significantly increased while expression of Retnla, a gene related to anti-apoptosis, was dramatically decreased in the fetal lung (E14.5) of PpargΔLuEpC mice. In addition, expression of Pthlh, a gene phenotypically expressed in the congenital cystic adenomatoid malformation (CCAM), was increased at E14.5 to E18.5 in the lung of PpargΔLuEpC mice. Cell culture studies revealed that PPARγ could bind to promoter region of Pthlh gene as a repressor in the immortalized mouse lung epithelial cell line MLE-15. Surprisingly, phenotypic changes in MLE-15-shPparg cells, stably transfected with shPparg plasmid, were similar to the PpargΔLuEpC mice model. In addition, MLE-15-shPparg cells were easily detached from the cultured plate when cold phosphate buffered saline was applied. Furthermore, expression of Cdh1, a gene related to cell adhesion, was significantly reduced in the MLE-15-shPparg cells. Taken together, PPARγ may play an important role in fetal lung development via alveolar cell-to-cell adhesion system.

Congenital pulmonary airway malformations: state-of-the-art review for pediatrician's use.

Congenital pulmonary airway malformations or CPAM are rare developmental lung malformations, leading to cystic and/or adenomatous pulmonary areas. Nowadays, CPAM are diagnosed prenatally, improving the prenatal and immediate postnatal care and ultimately the knowledge on CPAM pathophysiology. CPAM natural evolution can lead to infections or malignancies, whose exact prevalence is still difficult to assess. The aim of this "state-of-the-art" review is to cover the recently published literature on CPAM management whether the pulmonary lesion was detected during pregnancy or after birth, the current indications of surgery or surveillance and finally its potential evolution to pleuro-pulmonary blastoma. CONCLUSION: Surgery remains the cornerstone treatment of symptomatic lesions but the postnatal management of asymptomatic CPAM remains controversial. There are pros and cons of surgical resection, as increasing rate of infections over time renders the surgery more difficult after months or years of evolution, as well as risk of malignancy, though exact incidence is still unknown. What is known: • Congenital pulmonary airway malformations (CPAM) are rare developmental lung malformations mainly antenatally diagnosed. • While the neonatal management of symptomatic CPAM is clear and includes prompt surgery, controversies remain for asymptomatic CPAM due to risk of infections and malignancies. What is new: • Increased rate of infection over time renders the surgery more difficult after months or years of evolution and pushes for recommendation of early elective surgery. • New molecular or pathological pathways may help in the distinction of type 4 CPAM from type I pleuropulmonary blastoma.

Congenital cystic adenomatoid malformation of the lung (CCAM), a retrospective clinical audit and literature review in a tertiary centre in Scotland over a period of 14 years.

This work was a retrospective audit of CCAM - 1994 to 2008. A total of 26 cases were identified. Mean gestational age at diagnosis was 20 weeks. All were unilateral and had serial scans. In 31% the lesion resolved, 8% decreased, 42% were unchanged and 4% increased in size. Only one foetus developed hydrops. All were born alive. Of 8 foetuses where the CCAM was thought to have resolved, 6 had persistent lesions (overall sensitivity and PPV of US 64% and 69%, respectively). Computerised tomography performed better than chest X-ray in detecting lesions postnatally (sensitivity 100% vs 88%, PPV 95% vs 78%). Seventeen cases required surgery, 4 conservative management and 2 were discharged following negative CXR; 12% had associated anomalies. Four babies had recurrent chest infections. CCAMs have a good overall prognosis. CT scan rather than CXR should be performed to confirm the resolution of antenatally diagnosed lesions. Surgical management is the preferred option over conservative management.

Pathomechanisms of Congenital Cystic Lung Diseases: Focus on Congenital Cystic Adenomatoid Malformation and Pleuropulmonary Blastoma.

It is well established that a number of birth defects are associated with improper formation of the respiratory tract. Important progress has been made in the identification of components of the regulatory networks controlling lung morphogenesis. They comprise a variety of soluble factors, receptors, transcription factors, and miRNAs. However, the underlying molecular mechanisms remain unsolved and fundamental questions, such as those related to lung branching are still unanswered. Congenital cystic lung diseases consist of a heterogeneous group of rare lung diseases mainly detected prenatally and characterized by airway dilatation. Despite their apparent phenotypic heterogeneity, these malformations are proposed to be related to a common malformation sequence occurring during lung branching morphogenesis.

Retrospective Evaluation of Children with Congenital Pulmonary Airway Malformation: A Single Center Experience of 20 Years.

OBJECTIVES: Congenital pulmonary airway malformation (CPAM) is an uncommon congenital abnormality of the lungs that generally presents during prenatal period or early childhood. In this study, we aimed to evaluate clinical and pathologic findings of the children with CPAMs who were referred to our center between 1992 and 2011. MATERIAL AND METHODS: We reviewed 19 children with CPAM, who were diagnosed and treated at the Izmir Dr. Behçet Uz Children's Hospital between 1992 and 2011. All of them are alive and have been still followed up by our center. RESULTS: The study population consisted of 9 boys (47.4%) and 10 girls (52.6%) with a mean age of 3.26 (1 month - 13 years). Most newborns had respiratory distress, while recurrent pulmonary infections were detected in older children. Surgical treatment was performed on patients with subtypes I (n = 4; 21.1%), II (n = 8; 42.1%), III (n = 5; 26.3%), and IV (n = 2; 10.5%). In 13 cases (63.4%), lesions were located in the right lung and in almost all cases lesions were confined to one lobe. A one-month- old child with type I CPAM had multiple lesions involving two lobes and in only a newborn with type II CPAM, lesions were located bilaterally. There was no type 0 cases in this series. All cases were treated with lobectomy without any complication. CONCLUSION: In the present study, a realistic comprehensive picture of CPAM in a central children's hospital has been provided. In addition, we want to emphasize that complications and unnecessary medical treatment could be reduced with early surgery.

Unusual signal intensity of congenital pulmonary airway malformation on fetal magnetic resonance imaging.

Congenital pulmonary airway malformation (CPAM) is classified into pathologically different types. These types are sometimes distinguishable by fetal lung MRI and are usually observed as higher-signal lesions on T2-weighted images than normal lung. We describe a case of unusual CPAM resembling neoplasms, with a lower signal than is found in normal lung. Histopathology showed a large number of mucogenic cells but found no evidence that could explain this feature on fetal MRI. An unusual low-signal mass associated with a pulmonary cyst in fetal lung on MRI may suggest an unusual type 1 CPAM.

Sox2 regulates the emergence of lung basal cells by directly activating the transcription of Trp63.

Lung development is determined by the coordinated expression of several key genes. Previously, we and others have shown the importance of the sex determining region Y-box 2 (Sox2) gene in lung development. Transgenic expression of Sox2 during lung development resulted in cystic airways, and here we show that modulating the timing of ectopic Sox2 expression in the branching regions of the developing lung results in variable cystic lesions resembling the spectrum of the human congenital disorder congenital cystic adenomatoid malformation (CCAM). Sox2 dominantly differentiated naive epithelial cells into the proximal lineage irrespective of the presence of Fgf10. Sox2 directly induced the expression of Trp63, the master switch toward the basal cell lineage and induced the expression of Gata6, a factor involved in the emergence of bronchoalveolar stem cells. We showed that SOX2 and TRP63 are coexpressed in the lungs of human patients with type II CCAM. The combination of premature differentiation toward the proximal cell lineage and the induction of proliferation resulted in the cyst-like structures. Thus, we show that Sox2 is directly responsible for the emergence of two lung progenitor cells: basal cells by regulating the master gene Trp63 and bronchoalveolar stem cells by regulating Gata6.

EGFR mutation of adenocarcinoma in congenital cystic adenomatoid malformation/congenital pulmonary airway malformation: a case report.

An 80-year-old man underwent right upper lobectomy for the resection of multiple cysts accompanied by a nodule. The pathological diagnosis was adenocarcinoma with surrounding atypical epithelial cell proliferation in a Type 1 congenital cystic adenomatoid malformation/congenital pulmonary airway malformation. There was epidermal growth factor receptor mutation in the adenocarcinoma and surrounding atypical epithelial cells that had proliferated. Malignant transformation of congenital cystic adenomatoid malformation/congenital pulmonary airway malformation may be related to the epidermal growth factor receptor pathway in this case, with atypical epithelial cell proliferation as a precursor. We emphasize the importance of complete resection of congenital cystic adenomatoid malformation/congenital pulmonary airway malformation and the possibility of treatment with epidermal growth factor receptor tyrosine kinase inhibitors in epidermal growth factor receptor-mutated cases.

Congenital cystic adenomatoid malformation with associated mucinous bronchioloalveolar carcinoma in a neonate.

Congenital cystic adenomatoid malformation (CCAM) of lung is a rare hamartomatous disorder characterized by abnormal branching morphogenesis of the lung. We report an unusual case of a 2-day-old male newborn with a pulmonary cystic lesion and lobectomy revealed a CCAM of the lung that has overlapping features of type 1 and type 2, complicating with multifocal mucinous bronchioloalveolar carcinoma (BAC). The case indicates that malignant transformation can occur in very early stage of the infancy in the patients with CCAM of lung.