Rhabdomyosarcoma arising within congenital pulmonary cysts: report of three cases

Congenital lung malformations: Dysregulated lung developmental processes and altered signaling pathways

Congenital lung malformations comprise a diverse group of anomalies including congenital pulmonary airway malformation (CPAM, previously known as congenital cystic adenomatoid malformation or CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema (CLE), bronchogenic cysts, and hybrid lesions. Little is known about the signaling pathways that underlie the pathophysiology of these lesions and the processes that may promote their malignant transformation. In the last decade, the use of transgenic/knockout animal models and the implementation of next generation sequencing on surgical lung specimens have increased our knowledge on the pathophysiology of these lesions. Herein, we provide an overview of normal lung development in humans and rodents, and we discuss the current state of knowledge on the pathophysiology and molecular pathways that are altered in each congenital lung malformation.

Primary Pulmonary Alveolar Rhabdomyosarcoma in a Pediatric Patient: A Case Report With Literature Review

Rhabdomyosarcoma (RMS) is a rare soft tissue tumor originating from skeletal muscle that is mostly reported in children. The most common sites of involvement are the head, neck, and extremities. The 2020 WHO classification divide RMS into four types: embryonal, alveolar, pleomorphic, and spindle cell/sclerosing. Reports of RMS with primary lung origin are rare. We present a case of RMS in a 16-month-old boy who presented with a lung mass and microscopic examination with fluorescence in situ hybridization confirmed the diagnosis of alveolar RMS. In conclusion, RMS should be considered in the differential diagnosis of any lung mass with small round blue cell morphology in the microscopic evaluation and should be distinguished from metastatic RMS of other sites, pleuropulmonary blastoma, lymphoma, neuroblastoma, primitive neuroectodermal tumor (PNET)/EWING, and malignant peripheral nerve sheet tumors (MPNST).

Congenital lung lesions

Diagnosis and management of congenital lung malformations has evolved dramatically over the past several decades. Advancement in imaging technology has enabled earlier, more definitive diagnoses and, consequently, more timely intervention in utero or after birth, when indicated. These advancements have increased overall survival rates to around 95% from historical rates of 60%. However, further refinement of diagnostic technique and standardization of treatment is needed, particularly as the increased sensitivity of diagnostic imaging results in more frequent diagnoses. In this article, we provide an updated review of the diagnostic strategies, management, and prognosis of congenital lung malformations.

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.

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.

Intradiaphragmatic hybrid lesion: surgical decision-making and value of minimal invasive surgery

Hybrid lesions (HLs) have elements of congenital pulmonary airway malformation and extrapulmonary sequestration (EPS) and belong to the congenital lung lesions. EPS usually arises in the thorax or the abdomen but rarely in the diaphragm. The preoperative diagnostic work-up based on chest radiograph, ultrasound (US) and CT often shows imprecise results. Therefore, the exact localisation of the lesion can only be ascertained intraoperatively. Here we present a patient, with an intradiaphragmatic HL, and demonstrate the difficulties of surgical decision making regarding the localisation of the lesion and discuss the value of minimal invasive surgery.

Association between Congenital Lung Malformations and Lung Tumors in Children and Adults: A Systematic Review

INTRODUCTION

The appropriate management of asymptomatic congenital pulmonary malformations (CPMs) remains controversial. Prophylactic surgery is recommended to avoid the risk for development of pulmonary infections and to prevent the highly debated development of malignancy. However, the true risk for development of malignancy remains unknown. A systematic review analyzed all cases in which lung tumors associated with CPMs in both the pediatric and adult populations were described.

METHODS

A comprehensive literature search was carried out; it included all the cases in which an association between CPMs and malignant pulmonary lesions was reported.

RESULTS

In all, 134 publications were eligible for inclusion. In 168 patients CPM was found associated with lung tumor. The diagnosis was made in 76 children at a mean age of 3.68 ± 3.4, whereas in the adult population (n = 92) it was made at a mean age of 44.62 ± 16.09. Cough was the most frequent presenting symptom both in children and in adults. Most of the patients underwent lobectomy. The tumor most often associated with CPM was pleuropulmonary bastoma in children (n = 31) and adenocarcinoma (n = 20) or bronchioloalveolar carcinoma (n = 20) in adults. The CPM most frequenty associated with tumors in children was congenital cystic adenomatoid malformation (n = 37), especially type 1 (n = 21), whereas in adults it was bronchogenic cyst (n = 25), followed by congenital cystic adenomatoid malformation (n = 21).

CONCLUSIONS

CPMs should be followed up and never underestimated because they may conceal a tumor. Apparently, there is no age limit for malignant progression of CPMs and no limit of the interval between first detection of the CPM and appearance of the associated tumor.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

The argument for operative approach to asymptomatic lung lesions

Antenatal detection of congenital pulmonary airway malformations (CPAM) has improved immeasurably from its initial application in the 1980s and probably encompasses >80% of all such lesions. Accurate diagnosis still remains less reliable and definitive diagnosis requires detailed anatomical imaging (typically with CT scan) in the post-natal period. About 10% of all lesions will present with symptoms during the neonatal period and the choice of surgical intervention is then easy. For those that remain asymptomatic then there is still a degree of controversy about elective surgical resection. This article presents the case for elective surgery within the first year of life and aims to quantify the risks of non-intervention such as abscess, empyema, recurrent pneumonia, air-leak, and pneumothorax and various types of malignancy in such cases. The current surgical approach now includes both open muscle-sparing thoracotomy and thoracoscopic resection.

Multiple Bronchogenic and Gastroenteric Cysts Arising from the Stomach in a Patient with Abdominal Pain

Bronchogenic cysts arising from the stomach are uncommon. We discuss a young female patient with presumed enteric duplication cysts who was found to have three bronchogenic and gastroenteric cysts upon pathologic review. We discuss the pathophysiology of bronchogenic cysts and their malignant potential.

Congenital cystic lesions of the lung

Congenital cystic lesions of the lung are present in 1 in 10,000-35,000 births and present as a spectrum of anomalies. Majority of these cystic lesions comprise congenital cystic adenomatoid malformations, pulmonary sequestrations, congenital lobar emphysema, and bronchogenic cysts. Most of these lesions are nowadays detected antenatally, however some will present either in the newborn or during later childhood. A review of the aetiology, classification, natural history, investigations, and treatment of congenital cystic lung lesions is discussed.

Gastric bronchogenic cyst histologically diagnosed after laparoscopic excision: report of a case

Abdominal computed tomography of a 71-year-old man revealed a 3-cm mass in gastric cardia. Although the mass was widely attached to the gastric wall, no clear contrast enhancement was observed. Abdominal magnetic resonance imaging revealed the mass to have homogenous high intensity on T2W1 images and isointensity on T1W1 images. On diffusion-weighted imaging, no high intensity was observed. However, the mass had a smooth surface and was widely attached to the gastric wall, consistent with computed tomography findings. A gastric submucosal tumor was suspected. Laparoscopic tumor resection was performed. Histopathologic diagnosis of the mass was a bronchogenic cyst derived from the respiratory primordium originating in the foregut of the primitive intestine. Such cysts are mostly found in the mediastinum or thoracic cavity; their occurrence on the gastric wall is extremely rare. Despite this, we think that bronchogenic cysts should be considered in the differential diagnosis of abdominal unilocular cystic diseases.

Bronchogenic cyst of stomach: two cases report and review of the English literature

Bronchogenic cysts (BCs) are a rare clinical entity because of anomalism of foregut in the embryonic stage. They have been described mostly within the mediastinum and are uncommon reported arising from the stomach. In this article, we report two cases of BC of stomach identified by pathological examination after surgical resection. It is extremely difficult to make a definitive diagnosis preoperatively just based on imaging findings. Surgical resection may be indicated if malignancy is suspected, or the cyst is enlarging or infected or causing symptoms.

Antenatal and postnatal management of congenital cystic adenomatoid malformation

Congenital thoracic malformations (CTMs) are a heterogeneous group of rare disorders that may involve the airways or lung parenchyma. The authors have focused on the condition that causes the most controversy, namely, congenital cystic adenomatoid malformation (CCAM). The reported incidence is 3.5 and 0.94 per 10,000 live births for CTMs and CCAMs respectively. Ultrasound is the antenatal imaging modality of choice for screening for CCAMs whilst magnetic resonance imaging is complimentary for morphological and volumetric evaluation of the foetal lung. Most CCAMs are detected antenatally with only a small proportion presenting postnatally. Only a few CCAMs cause foetal problems, with foetal hydrops being the best predictor of death. Although many CCAMs regress during pregnancy, most remain detectable postnatally by CT scans. Surgical excision of symptomatic lesions is relatively straightforward, but management of asymptomatic lesions is controversial. Some surgeons adopt a "wait and see" approach operating only on those patients who develop symptoms, but others operate on asymptomatic patients usually within the first year of life. Due to the potential of malignant transformation, children should have long term follow up. There is an urgent need to delineate the natural history of antenatally detected CCAMs to guide future management.

Long term respiratory outcomes of congenital thoracic malformations

The advent of universal antenatal ultrasonography in many countries has revealed the full spectrum of congenital thoracic malformations (CTMs) and presented clinicians with a number of practical dilemmas to do with diagnosis and management. We present a review of the most common forms of CTMs, including congenital cystic adenomatoid malformation, bronchopulmonary sequestration, and lobar and segmental emphysema.

Congenital cystic adenomatoid malformation: is there a need for pregnancy termination?

Aim. Congenital cystic adenomatoid lung malformation is a rare unilateral dysplasia of the lung. Three pathologic types are described in the literature: type I with cysts >2 cm, type II with cysts <1 cm, and type III with microcysts. The aim of this paper is to present a case of a fetus with congenital cystic adenomatoid lung malformation and discuss the necessity for pregnancy termination according to its prognosis and future mortality. Case. A 36-year-old pregnant woman (para: 1, gravida: 1) presented in our department for anatomy ultrasound screening at 20 + 1 weeks of gestation. The ultrasound detected a cystic adenomatoid right lung malformation measuring 1.45 × 1.67 cm which caused mediastinal shift of the heart and the lung to the left side. Other findings were cysts of the choroid plexus and echogenic intracardiac foci. The parents after genetic counseling decided pregnancy termination. The pregnant received cabergoline for ablactation. Conclusion. Congenital cystic adenomatoid lung malformation has different prognosis according to the type (69% in type I, 0% in types II and III). Fetal hydrops, cardiac and skeletal anomalies, Potter's syndrome, and gastrointestinal atresia are common cofindings. Genetic counseling is necessary, and pregnancy termination is proposed to the cases with poor prognosis.

[Congenital lung malformations--when to operate?]

Advances in antenatal imaging over the past 10 years have completely changed diagnosis and management of congenital lung disease, especially for congenital cystic adenomatoid malformations and sequestrations that are the two lesions most commonly detected. If early surgical excision is required for symptomatic cases, management of asymptomatic malformations is still discussed. The natural evolution and consequences of later complications of congenital lung malformations need to be compared with the benefits of elective resection and surgical morbidity. Complete regression of sequestrations or clinical and morphological improvement in congenital lobar emphysema pleads for clinical watching. On the other hand, resection is advocated for cystic malformations, because of an increased risk of acute respiratory distress, later infections and the possibility of malignant transformation. Even though the proportion of asymptomatic patients that go on to develop symptoms is hard to evaluate, an argument for elective surgery is a better outcome than emergency surgery. Further studies and long term follow-up are still needed to understand the natural history of congenital lung malformations precisely and help to define the optimal way in which to manage them.

Open resections for congenital lung malformations

AIM

Pediatric lung resection is a relatively uncommon procedure that is usually performed for congenital lesions. In recent years, thoracoscopic resection has become increasingly popular, particularly for small peripheral lesions. The aim of this study was to review our experience with traditional open lung resection in order to evaluate the existing "gold standard."

MATERIALS AND METHODS

We carried out a retrospective analysis of all children having lung resection for congenital lesions at our institution between 1997 and 2004. Data were collected from analysis of case notes, operative records and clinical consultation. The mean follow-up was 37.95 months. The data were analyzed using SPSS.

RESULTS

Forty-one children (13 F/28 M) underwent major lung resections during the study period. Their median age was 4.66 months (1 day-9 years). The resected lesions included 21 congenital cystic adenomatoid malformations, 14 congenital lobar emphysema, four sequestrations and one bronchogenic cyst. Fifty percent of the lesions were diagnosed antenatally. Twenty-six patients had a complete lobectomy while 15 patients had parenchymal sparing resection of the lesion alone. Mean postoperative stay was 5.7 days. There have been no complications in any of the patients. All patients are currently alive, asymptomatic and well. None of the patients have any significant chest deformity.

CONCLUSIONS

We conclude that open lung resection enables parenchymal sparing surgery, is versatile, has few complications and produces very good long-term results. It remains the "gold standard" against which minimally invasive techniques may be judged.

Radical resection of pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare intrathoracic neoplasm of early childhood that occurs in the lung or visceral pleura. We present a case of a 5-year-old boy with a cough, left-sided chest pain and progressive dyspnea on exertion. The patient had had an operation for a congenital lung cyst of the left lower lobe, six months prior to the present admission. A CT showed a heterogeneously enhancing mass lesion filling the left hemithorax. CT-guided fine needle aspiration cytology of the mass was inconclusive. En bloc resection of the mass along with left lower lobe, the involved ribs and left diaphragm was performed. The diaphragmatic defect was repaired using prolene mesh. Histopathology of the resected specimen showed solid and cystic areas consistent with type II PPB. The patient received adjuvent chemotherapy and was doing well 23 months after surgery. Radical resection of the tumor followed by adjuvent chemotherapy provides the only hope of salvaging cases of type II or type III PPB.

Open fetal surgery for life-threatening fetal anomalies

After more than two decades of experimental and clinical work, fetal surgery is an accepted treatment option for highly selected fetuses with life-threatening anomalies. Fetal lung masses associated with hydrops are usually fatal. These lesions can be resected in utero if they are predominantly solid or multicystic. Fetal sacrococcygeal teratoma complicated with progressive high output cardiac failure may benefit from in-utero resection of the tumor. Important lessons have been learned about perioperative management and maternal, fetal, and neonatal outcomes after open fetal surgery.

Management of fetal lung lesions

Prenatal diagnosis provides insight into the in utero evolution of fetal thoracic lesions such as congenital cystic adenomatoid malformation (CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema, and mediastinal teratoma. Serial sonographic study of fetuses with thoracic lesions has helped define the natural history of these lesions, determine the pathophysiologic features that affect clinical outcome, and formulate management based on prognosis.

Fetal and placental malignancies: prenatal diagnosis and management

Fetal and placental malignancies are rare complications during pregnancy, but when they occur they may present significant challenges for the perinatology team. Owing to their rarity, there is limited information on many of these entities, with much data derived from individual case reports or small case series. Prenatal diagnosis of these entities is rare and inconsistent, usually in the form of isolated case reports. In the majority of fetal tumors, prenatal features are those of a mass lesion, with or without other non-specific features of fetal compromise such as polyhydramnios, fetal hydrops or intrauterine death, the final diagnosis in most cases being based on postnatal pathological examination.Expectant management is almost always indicated antenatally, with serial ultrasound examinations performed to detect rapid enlargement, metastasis or secondary fetal complications, such as non-immune hydrops, which may require intervention. Delivery should be planned in a specialist center in conjunction with pediatric surgeons and oncologists to allow appropriate neonatal management. Placental malignancy is most commonly in the form of gestatational trophoblastic disease, which requires assessment and management in specialist centers.

Pulmonary cysts in early childhood and the risk of malignancy

Surgery for congenital and early childhood lung cysts is often dictated by symptoms such as respiratory distress, infection or pneumothorax. Asymptomatic cysts present a therapeutic dilemma: surgical intervention and "conservative" observation have advocates. The risk of malignancy in such cysts is considered by some an indication for surgical intervention and is reviewed in this paper. Pleuropulmonary blastoma (PPB) is the most frequent malignancy associated with childhood lung cysts. Although rare, PPB occurs predictably in certain clinical and familial situations. This unique biology of PPB can inform the cyst management decision. The earliest manifestation of PPB is a malignant lung cyst in young children, clinically and radiographically indistinguishable from benign congenital lung cysts. Histopathologic examination differentiates cystic PPB from the benign cystic variants. Surgical excision of cystic PPB (with or without chemotherapy) cures approximately 85-90% of children. If not excised, cystic PPB evolves to cystic/solid or solid high-grade sarcoma (cure rate 45-60%) by age 2-6 years. Numerous reports of "malignancy in a congenital lung cyst" are now understood as the characteristic progression of cystic PPB. PPB is genetically determined in many cases. Detailed family history may reveal the hallmarks of PPB in the patient or young relatives: a unique constellation of diseases including lung cysts, cystic nephroma, childhood cancers, stromal sex-chord ovarian tumors, seminomas or dysgerminomas, intestinal polyps, thyroid hyperplasias, and hamartomas. Pneumothorax and multifocal/bilateral lung cysts also characterize PPB. These diagnoses predict that a lung cyst is more likely PPB than a benign congenital cyst. Patients fitting this pattern deserve histologic diagnosis. The genetic basis for this heritable syndrome is unknown but is being actively investigated.

Bronchogenic cyst of the stomach involved with gastric adenocarcinoma

Bronchogenic cyst, a congenital anomaly mostly found in the mediastinum, rarely arises in the stomach. A 43-year-old man had epigastric pain and was diagnosed as having gastric adenocarcinoma. Abdominal ultrasonography showed hepatic cyst, and computed tomography and magnetic resonance imaging revealed a cystic lesion near the stomach. At surgery, the cystic lesion was found to be located at the lesser curvature of the stomach where the cancer invasion was seen. Total gastrectomy with combined resection of the cystic lesion was performed. Pathologically, the cyst wall was lined by pseudostratified ciliated columnar epithelium, subepithelial mixed seromucinous glands and smooth muscle bundles. The pathological diagnosis was bronchogenic cyst of the stomach involved with gastric adenocarcinoma. Based on a similar association between gastric diffuse submucosal cysts and gastric cancer in the previous reports, it is possible that chronic inflammation from bronchogenic cysts to the gastric mucosa may cause adenocarcinoma in the stomach. At surgery, complete combined resection without rupture of the bronchogenic cyst involved with the gastric adenocarcinoma is needed for treatment of gastric cancer to prevent dissemination of cancer cells considering when cancer cells have invaded beyond the pseudostratified ciliated columnar epithelium and within the bronchogenic cyst.

Prognostic factors in pleuro-pulmonary blastoma

PURPOSE

To evaluate the prognostic factors in a series of children affected by pleuropulmonary blastoma (PPB).

PATIENTS AND METHODS

Clinicopathological findings, treatment, and outcome of 22 PPB cases observed in 13 Italian Associations for Pediatric Hematology and Oncology centers are reported. Clinical data, surgical notes, pathologic findings, and summaries of treatment were taken from the charts and correlated with outcome by standard statistical methods.

RESULTS

The series included 22 patients (14 males) with a median age of 30.5 months followed up for a median of 22 months (range 2-176 months). In nine patients the PPB developed with lung involvement only. Congenital lung cysts were recorded in five cases. Nine patients had recurrences. Gender, side, tumor size, pre-existing lung cysts, and extent of surgical resection at diagnosis did not significantly affect survival by univariate analysis. Achieving total resection of the tumor at any time of treatment resulted in a significantly better prognosis (P = 0.01), whereas extrapulmonary involvement at diagnosis resulted in a significantly worse prognosis (P = 0.01). Estimated 15-year event-free and overall survival rates were 44 and 49% for all patients, respectively.

CONCLUSIONS

PPB is an aggressive neoplasm. Total resection of PPB performed at any time of treatment appears to provide a better outcome, whereas extrapulmonary involvement at diagnosis worsens the prognosis.

Pleuropulmonary blastoma: cytogenetic and spectral karyotype analysis

Pleuropulmonary blastoma (PPB) is a rare neoplasm of the pleuropulmonary mesenchyme. The molecular mechanisms underlying the genesis of this tumor are of particular interest as a large number of affected patients as well as their relatives have concurrent disease including additional dysplasia or neoplasia. To date, detailed karyotypes have been published on a limited number of cases. We report clinical, pathologic, and cytogenetic data in 2 cases of PPB including spectral karyotyping in 1 of them. Additionally, we conducted a review of the literature and compiled 15 published karyotypes of this tumor. Gain of chromosome 8 material was a highly prevalent finding in PPB, most times occurring as trisomy, but tetrasomy of the long arm was also frequent. Other occurring abnormalities, in order of observed frequency, included loss of 17p, loss of chromosome 10 or 10q, rearrangement of 11p, loss of chromosome X or Xp, gain of chromosomes/arms 1q, 2, and 7q, and loss of 6q and 18p. Loss of 10q has not been previously emphasized in PPB. The significance of these chromosome findings is discussed in relation to tumorigenesis.

Cytogenetic and p53 profiles in congenital cystic adenomatoid malformation: insights into its relationship with pleuropulmonary blastoma

Congenital cystic adenomatoid malformation (CCAM), a developmental anomaly of lung, shares many features with the pediatric tumor pleuropulmonary blastoma (PPB). Both may show benign epithelium-lined cysts and mesenchymal proliferation, often with skeletal muscle differentiation. Before its recognition as a distinct entity, PPB was described in several reports as "rhabdomyosarcoma arising in CCAM." Abnormal karyotypes in PPB often show excess material from chromosome 8. It has also been suggested that PPB may harbor p53 mutations. We examined the karyotype and searched for p53 mutations (via immunostaining and single-strand conformation polymorphism analysis) in 11 CCAM and in 2 PPB. Karyotypes were normal in all CCAM and showed clonal abnormalities in both PPB. There was marked and diffuse immunopositivity for nuclear p53 in the epithelial cells of CCAM and PPB. Strong staining was also observed in approximately 50% of the stromal cells in all PPB, but was seen in the stroma of only 2 of 10 CCAM, where it was faint and focal. TP53 mutations were not identified in CCAM or PPB. We conclude that CCAM does not contain the clonal chromosomal aberrations reported in PPB and shows less stromal p53 immunostaining than PPB. Since p53 mutations were not identified in either entity, the observed p53 immunoreactivity may be caused by another mechanism; its role in PPB and CCAM pathogenesis remains to be determined. Overall, these findings provide evidence that CCAM is nonneoplastic. Although some may view CCAM as a PPB precursor, it remains biologically distinct in terms of karyotype and p53 status.

Rhabdomyosarcoma arising within congenital cystic adenomatoid malformation

Rhabdomyosarcoma arising within a congenital cystic adenomatoid malformation (CCAM) is an unusual entity. The patient underwent a lobectomy of his right lower lobe of lung due to a CCAM at the age of two. One year later, he developed a solid embryonal rhabdomyosarcoma at the same location. He received 1-year period chemotherapy and when the tumor reduced to a resectable size, surgical excision was done. The tumor cells appeared more differentiated after chemotherapy. The patient remains disease free to date, 16 months after surgery.

Primary rhabdomyosarcoma of the lung arising over cystic pulmonary adenomatoid malformation

The authors report the case of a 2-year-old girl with pulmonary cystic adenomatoid malformation type II who presented with a mass on the lower lobe of the left lung. Resection and histological examination revealed pleomorphic rhabdomyosarcoma. Chemotherapy and radiotherapy followed the operation and the girl is alive and in perfect condition 10 years after the operation. The literature on primary rhabdomyosarcoma of the lung in children is reviewed.

Postnatal spontaneous resolution of congenital cystic adenomatoid malformations

PURPOSE

Although antenatal resolution of congenital cystic adenomatoid malformations (CCAMs) is well documented, complete spontaneous postnatal resolution is rare, its existence even questioned by some.

METHODS

All cases of antenatally diagnosed CCAMs over 7 years were retrospectively reviewed. Inclusion criteria were the following: (1) antenatal diagnosis of CCAM, (2) persistence on postnatal imaging, and (3) subsequent spontaneous resolution on postnatal imaging.

RESULTS

Of 56 antenatally diagnosed CCAMs, 2 patients were identified. Both had macrocystic lesions. In case 1, the CCAM that filled the hemithorax on antenatal ultrasound was smaller on postnatal chest radiograph and disappeared by age 37 months on computed tomography. Case 2 had significant reduction of the CCAM at birth (persistence of the lesion on initial radiographs and ultrasound was documented). By 5 months, the lesion was not evident on computed tomography. Neither case was associated with symptoms, polyhydramnios, hydrops, or other abnormalities.

CONCLUSIONS

In patients with an antenatal diagnosis of CCAM, spontaneous resolution may occur postnatally in 4% of cases. Significant reduction in CCAM size may portend possible disappearance and therefore warrants an observational period before resection.

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.

The management of asymptomatic congenital lung malformations

Congenital Pulmonary Airway Malformation (CPAM) and lung sequestration are often discovered on routine prenatal sonography. While some lesions may be large and cause serious complications in the fetus or newborn, many will be asymptomatic at birth. 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 CPAM and intralobar sequestration (ILS) 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 CPAM and ILS, it is best not to wait for complications to occur. We recommend surgery at 3 to 6 months of life at the latest, to allow compensatory lung growth to occur. At this age the postoperative course is usually smooth and long-term follow- up has shown normal respiratory function. The management of small non- communicating extralobar sequestrations is more controversial; it is known that these can remain asymptomatic throughout life but complications may develop and they are sometimes difficult to differentiate from neuroblastoma.

Congenital anomalies of the fetal/neonatal chest

The ability to identify and confidently diagnose a wide range of congenital fetal thoracic lesions has increased tremendously in the past 2 decades with the emergence of high-resolution sonography and ultrafast MRI sequences. Imaging studies constitute a vital component in the diagnosis of these lesions, whether in the fetal, neonatal or childhood periods. In addition to providing a road map for potential intervention, imaging techniques have provided important information about normal development, natural history, and prognosis. In the prenatal stage, these features aid in family counseling, pregnancy management, and the identification of a subgroup of patients who may benefit from fetal intervention. In the neonatal and childhood periods, imaging studies facilitate timely diagnosis and institution of appropriate therapeutic strategies.

Current outcome of antenally diagnosed cystic lung disease

BACKGROUND/PURPOSE

The natural history of parenchymal lung lesions such as congenital cystic adenomatoid malformation (CCAM) and pulmonary sequestration (PS) has been altered by the advent of antenatal ultrasonography. Initial reports were characterized by a high (about 30%) incidence of adverse features (eg, hydrops) and a poor outcome and did not accord with our recent experience. The authors have reviewed the outcome of fetuses that had been diagnosed in a large tertiary referral fetal medicine unit with the aim of delineating current experience. The term cystic lung disease was used throughout to avoid unjustifiable histologic precision.

METHODS

The scans of all fetuses that had been diagnosed with cystic lung disease between January 1995 and July 2001 were reviewed. The outcome of each pregnancy was established, and, where possible, all infants underwent appropriate investigations, including thoracic computed tomography (CT) scans.

RESULTS

Sixty-seven fetuses had a cystic lung abnormality diagnosed from January 1995 to July 2001. The median (range) age at diagnosis was 21 (19 to 28) weeks. The lesion was right sided in 29 (43%), left in 36 (54%), and bilateral in 2 (3%); it was characterized as dominantly macrocystic in 27 (40%), microcystic in 35 (52%), and mixed in 5 (8%). Mediastinal shift was present in 30 fetuses (45%). Severe signs of fetal distress (eg, hydrops) were present in 5 fetuses (7%). Antenatal intervention was performed in 4 fetuses (thoraco-amniotic shunts [n = 3] and percutaneous intrauterine laser therapy [n = 1]). Sixty-four (96%) of the fetuses were born alive. There was 1 termination of pregnancy and 2 intrauterine deaths (all severe microcystic lesions). Forty-two infants (63%) underwent thoracotomy and appropriate excisional surgery at a median of 7.5 months (range, 1 day to 34 months). Two infants (which included the fetus having intrauterine laser therapy) died early in the postnatal period. Both were large microcystic lesions and had antenatal features of severe fetal distress. Twelve infants were investigated in the postnatal period but did not undergo surgery. Ten infants were not appropriately investigated or were lost to follow-up. Histologic examination showed definitive diagnostic features of CCAM (n = 25) or PS (n = 6). Other lesions with hybrid features of both were also seen (n = 11). There was a degree of correlation between antenatal ultrasound features (size of cyst [P =.03], in-utero behavior [P =.06], mediastinal shift [P = 0.05]) and the need for surgery but not with the final histologic diagnosis. Surgical excision was required in 45% of lesions showing late-gestation "resolution."

CONCLUSIONS

Antenatally diagnosed "cystic lung disease" has an excellent prognosis in the absence of signs of severe fetal distress. The need for surgery should be based on appropriate postnatal investigations (eg, CT scans), rather than on antenatal behavior.

Management of fetal lung lesions

We have learned from prenatal diagnosis that there is a wide spectrum of clinical severity for fetuses that have a lung mass. Accurate prognostic information is necessary for providing appropriate management and parental counseling. If an associated life-threatening anomaly is present or if the mother is ill with the mirror syndrome, then the family might choose to terminate the pregnancy. If the fetus is not hydropic and an isolated fetal lung lesion is present, the mother is followed by serial ultrasound and arrangements are made for the best possible care after birth. Some CCAMs and many BPSs will shrink in size, so it is important to try to differentiate these lesions using prenatal diagnostic criteria, although this technique is not always possible. All fetuses that had fetal thoracic masses without hydrops in our series survived in the setting of maternal transport, planned delivery, and postnatal evaluation at a facility with ECMO capability. Many of the babies that had large lesions at our center required ventilatory support, and six babies needed treatment with ECMO. Our impression is that these nonhydropic fetuses that had lung masses had less lung hypoplasia and a much better prognosis than those that had diaphragmatic hernia despite a similar degree of mediastinal shift as judged by prenatal sonography. In asymptomatic neonates that have a cystic lung lesion, we believe that elective resection is warranted because of the risks of infection and occult malignant transformation. Malignancies consist mainly of pleuropulmonary blastoma in infants and young children and bronchioloalveolar carcinoma in older children and adults. After confirmation of CCAM location by postnatal chest CT scan with intravenous contrast, we recommend elective resection at 1 month of age or older. This age has been chosen because anesthetic risk in babies decreases after 4 weeks of age. An experienced pediatric surgeon can safely perform a lobectomy in infants with minimal morbidity. Early resection also maximizes compensatory lung growth. In contrast, we have usually followed patients with a tiny, asymptomatic, noncystic BPS if we are confident of the diagnosis based on postnatal imaging studies. We do not favor the approach of catheterization and embolization for the treatment of larger BPS lesions. If the fetus is hydropic at presentation or if hydrops develops during serial follow-up, management depends upon the gestational age. For hydropic fetuses of greater than 32 weeks' gestation, early delivery should be considered so that the lesion can be resected ex utero, but the neonatal outcome is dismal. We recently managed two such cases using an ex utero intrapartum therapy (EXIT) strategy with resection of the mass during the EXIT procedure. Both fetuses survived and one required the use of ECMO. For hydropic fetuses of less than 32 weeks' gestation, there is now a new therapeutic option, treating the lesion before birth.

Fetal surgery for lung lesions, congenital diaphragmatic hernia, and sacrococcygeal teratoma

After more than 2 decades of experimental and clinical work, fetal surgery is an accepted treatment option for highly selected fetuses with life-threatening anomalies. Fetal lung masses associated with hydrops are nearly 100% fatal. These lesions can be resected in utero if they are predominantly solid or multicystic. Thoracoamniotic shunt placement may be effective in the setting of a single large cyst. Fetuses diagnosed with left congenital diaphragmatic hernia before 26 weeks' gestation with associated liver herniation and a low right lung to head circumference ratio have a relatively poor prognosis with conventional therapy after birth, but in utero therapeutic approaches have yet to show a comparative survival benefit. A prospective randomized trial is required to critically evaluate the efficacy of fetal tracheal occlusion for severe diaphragmatic hernia. Fetal sacrococcygeal teratoma complicated with progressive high output cardiac failure may benefit from in utero resection of the tumor.

Thoracoscopic lobectomy for prenatally diagnosed lung lesions

PURPOSE

The aim of this report is to assess the technique and outcome of thoracoscopic lobectomy for asymptomatic prenatally diagnosed lung lesions.

METHODS

From June 1999 to March 2002, 14 consecutive asymptomatic patients with a prenatal diagnosis of congenital cystic adenomatoid malformation or pulmonary sequestration, ages 3 to 15 months, underwent postnatal thoracoscopic lobectomy. Single-lung ventilation and controlled pneumothorax with low pressure (4 torr) and low flow (1.0 L/min) were used in all. Follow-up ranged from 4 to 35 months.

RESULTS

All procedures were completed successfully using 3 ports. Rather than using stapling devices or clips, pulmonary vessels were sealed and the fissure completed (when necessary) with the Ligasure thermal energy device. Eleven lesions were on the left (10 lower lobe), and 3 were in the right lower lobe. The mean operating time was 110 minutes. The average hospital stay was 38 hours. There were no intraoperative or postoperative complications.

CONCLUSIONS

This is the first report of a completely thoracoscopic technique for pulmonary lobectomy in small children. Thoracoscopic lobectomy is a relatively quick and safe procedure, and the cosmetic result is excellent. Early resection obviates the risk of infection in these lesions.

Congenital cystic lung disease: diagnostic and therapeutic considerations

Congenital lung cysts such as congenital cystic adenomatoid malformation, pulmonary sequestration, congenital lobar emphysema, and bronchogenic cysts are rare but fascinating anomalies of lung development. While there are many similarities in terms of their presenting features, there are particular differences between the diagnostic groups that are important to highlight, especially in relationship to approaches to imaging and long-term outcome. A case of each entity is presented with an emphasis on the contemporary approach to diagnostic investigations and therapeutic options.