Rhabdomyosarcoma arising within congenital cystic adenomatoid malformation

Type II pleuropulmonary blastoma mistaken for rhabdomyosarcoma: A case report

INTRODUCTION

Pleuropulmonary blastoma (PPB) is rare, representing 0.3 % of all pediatric cancers. PPB is classified into three subtypes and may progress from type I to types II and III, with a worse prognosis. Given its rarity, the diagnosis is frequently challenging.

CASE PRESENTATION

We report an occurrence of PPB in a 3-year-old girl, who presented recurrent pneumopathy. Imaging investigations revealed a large solid lesion in the left hemithorax. Biopsy followed by histological analysis suggested rhabdomyosarcoma. The patient received neoadjuvant chemotherapy before proceeding to complete tumor excision. Surgical exploration revealed that the tumor was primitively related to parietal pleura and lower lobe of left lung. Histopathology of the tumor retained a definitive diagnosis of PPB type II. Postoperative course was uneventful, and a cerebral MRI ruled out brain metastasis. Adjuvant chemotherapy was administered.

DISCUSSION

Clinical expression of PPB is nonspecific and variable. It ranges from a dry cough to respiratory distress. Standard radiography is the first examination to perform and CT is the gold standard for characterization thoracic masses. Surgery and chemotherapy are the pillars of treatment. Indications depend on the tumor type, its extent and its resectability.

CONCLUSION

PPB is an aggressive tumor that occurs only in children. Due to the rarity of PPB, evidence on optimal treatment is still insufficient. Careful follow-up is necessary searching for local recurrence or metastasis.

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).

Multimodality treatment including whole pleura radiation therapy for DICER1-associated pediatric pleuropulmonary blastoma

Limited data are available regarding radiation therapy in pediatric pleuropulmonary blastoma (PPB). We report the case of a 3-year-old girl with type II PPB successfully treated with trimodality therapy including multiagent chemotherapy, resection, and whole pleura radiation therapy. While longer follow-up is required to confirm ultimate local tumor control and long-term post-treatment sequelae, currently 3.5 years following therapy, she is well, without recurrent disease or observable toxicity. The goal of this report is to add our experience to the literature regarding PPB, its management, and treatment, as prospective randomized controlled trials are not feasible due to the rarity of this disease.

Prenatal and Postnatal Management of Congenital Pulmonary Airway Malformation

Congenital pulmonary airway malformation (CPAM) is one of the most common lung lesions detected prenatally. Despite the research efforts made in the past few years, controversy and lack of clarity in the literature still exist regarding nomenclature, classification, pathogenesis and the management of CPAM. Therefore, it is of greatest importance to delineate the natural history of CPAMs and to create a consensus to guide the management and follow-up of these lesions. This review will focus on classification systems, highlighting the most recent advancements in pathogenesis, and current practice in the prenatal diagnosis of CPAM. Strategies of prenatal management and postnatal management will be reviewed. Long-term follow-up, including lung cancer risk, is discussed and an outcome perspective is presented.

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.

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.

FGF10 Signaling differences between type I pleuropulmonary blastoma and congenital cystic adenomatoid malformation

Background

Type I pleuropulmonary blastoma (PPB) and congenital cystic adenomatoid malformation of the lung (CCAM) are cystic lung diseases of childhood. Their clinical and radiological presentations are often similar, and pathologic discrimination remains difficult in many cases. As a consequence, type I PPB and CCAM are frequently confused, leading to delayed adequate management for type I PPB. Recent studies have suggested a role for fibroblast growth factor (FGF) 10 signal pathway in CCAM pathogenesis. The objective of our study was to determine whether FGF10 signaling differs between CCAM and type I PPB.

Methods

Immunohistochemical studies were performed for expression of FGF10, its receptor FGFR2b, and its inhibitor sonic hedgehog (SHH) in focal type I PPB (n=6), CCAM type I (n=7), CCAM type II (n=7), and control lungs (n=5).

Results

FGF10, FGFR2b, and SHH expressions differed markedly between type I PPB and both types of CCAM. Type I and type II CCAM cystic walls expressed FGF10, FGFR2b, and SHH, whereas staining was absent or poor in type I PBB cystic walls. Expression of FGF10, FGFR2b, and SHH did not differ between CCAM cystic walls and control airway walls.

Conclusions

These findings show that immunohistochemistry with FGF10, FGFR2b, or SHH could be useful in differentiating CCAM from type I PPB, when a child presents with a focal cystic lung lesion. The absence of strong expression of FGF10, FGFR2b, and/or SHH makes the diagnosis of CCAM very doubtful.

Shall all congenital cystic lung malformations be removed? the case in favour

The need to systematically remove congenital cystic lung lesions is based on three main arguments. First, cystic malformations are often considered as congenital cystic adenomatoid malformations (CCAM), while other less favorable diagnoses are possible, such as pleuropulmonary blastoma. Only postsurgical pathological analysis allows diagnosis. Second, there are clinical and biological arguments for considering macrocystic lesions as likely to degenerate. The only prevention is surgical removal. Finally, there is no recommendation on how to follow these children, in the absence of removal, causing unnecessary family stress. This seems unjustified, compared to a feasibility of thoracoscopic removal in most cases.

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.

Pleuropulmonary blastoma: a single-institution experience

Pleuropulmonary blastoma (PPB) is a rare primary intrathoracic mesenchymal malignancy that occurs exclusively in early childhood. Twelve patients were diagnosed with PPB (1 type I, 5 type II, and 6 type III) between 1979 and 2009 at our institution. Upfront complete tumor resection was successful in 5 of 6 patients. Six patients had biopsy followed by neoadjuvant chemotherapy, 2 had complete tumor resection, and 2 had microscopic residual disease after surgery. All patients received vincristine, dactinomycin, and cyclophosphamide chemotherapy. Eight received additional chemotherapy with doxorubicin, cisplatin, etoposide, or ifosfamide. Three patients received local irradiation. The 5-year event-free and overall survivals were 33% ± 14% and 42% ± 14%, respectively. Median time to progression was 8 months. Five of 9 patients with gross total resection survived, whereas all 3 with gross residual disease died. Three of 5 survivors did not receive radiation. A high index of suspicion for PPB must be maintained in all patients diagnosed with intrathoracic sarcoma in early childhood. Gross total resection is necessary for cure, and selected patients do not require radiation therapy.

Is radical lobectomy required in congenital cystic adenomatoid malformation?

BACKGROUND

The extent of surgical resection in the management of congenital cystic adenomatoid malformation (CCAM) located in 1 pulmonary lobe remains controversial. Although lobectomy seems to be the best treatment to avoid recurrent pulmonary infection and neoplasia, neither retrospective nor prospective studies have been done to our knowledge. Besides, many reports claim that there are advantages of parenchyma-saving resections. The aim of our study was to determine whether it was necessary to perform an extended resection in these cases.

MATERIALS AND METHODS

We retrospectively reviewed all patients who had undergone a thoracoscopic lobectomy for CCAM located to 1 pulmonary lobe between January 2007 and January 2009. A thoracic radiologist performed a single blind review of all preoperative computed tomographic (CT) scans, mentioning the presence or absence of distant lesions from the main cysts of CCAM within the pulmonary lobe. The pathologist who analyzed the pulmonary lobectomy specimen was aware of the diagnosis but not the CT report.

RESULTS

Twenty-five patients underwent thoracoscopic lobectomy for congenital lung malformations, including 12 with CCAM. All had a positive prenatal sonogram. The median age at surgery was 12 months (range, 2-24 months). The preoperative CT showed only 2 cases with distant lesions within the affected pulmonary lobe, whereas the histologic study of the surgical specimen identified 6 cases. The sensitivity of the CT scan was low, 33%, whereas its specificity was high, 100%. Furthermore, the preoperative CT negative predictive value was 60%. The median time of follow-up was 7.5 months.

CONCLUSION

Adequate treatment of CCAM in children requires a lobectomy because of poor sensitivity and very poor negative predictive value (60%) of the preoperative CT to determine distal adjacent lesions. A prospective study on a larger number of patients is required to confirm these observations.

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.

Minimally invasive surgery in the neonate

The advent of minimally invasive surgical techniques in the neonate has been delayed due to the limited working space and the unique physiology of the newborn. In the last decade, with the introduction of new instruments and techniques, many of the initial problems have been solved making minimally invasive surgery feasible for a variety of indications in the neonate and a favored approach in specialized centers around the world. Although an increasing number of reports document the feasibility of this exciting technique, data demonstrating its benefit compared to conventional surgery is limited. This review focuses on recent developments in minimally invasive surgery in neonates and the evidence for its use.

Commonly encountered surgical problems in the fetus and neonate

Neonatal surgical care requires a current understanding of pre- and postnatal intervention for a myriad of congenital anomalies. This article includes an update of the recent information on commonly encountered fetal and neonatal surgical problems, highlighting specific areas of controversy and challenges in diagnosis. The authors hope that this article is useful for trainees and practitioners involved in any aspect of fetal and neonatal care.

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.

Primary pulmonary rhabdomyosarcoma in a 5-month-old boy: a case report

Primary pulmonary rhabdomyosarcoma (RMS) in the pediatric population is a rare entity. A 5-month-old boy initially treated for pneumonia was proven to have a primary pulmonary RMS, which was resected via thoracotomy. After a course of chemotherapy following the Children's Oncology Group low-risk RMS protocol (ARST0331), a restaging chest computerized tomography scan showed local recurrence, which was also resected by open thoracotomy. The patient is currently undergoing local radiotherapy and salvage chemotherapy regimen. This patient is the youngest reported to date with this entity. The prognostic significance of his young age and the morphologic findings of his tumor are unclear.

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.

A neonate with coexisting congenital cystic adenomatoid malformation of the lung and alveolar capillary dysplasia: a case report with review of literature

OBJECTIVE

First report of a term neonate with coexistent congenital cystic adenomatoid malformation (CCAM) of the lung and alveolar capillary dysplasia (ACD).

METHODS AND DESIGN

Case report and literature review. Our institutional review board waived the need for consent.

SETTING

We describe a term neonate with antenatally diagnosed CCAM and persistent pulmonary hypertension of the newborn (PPHN) who underwent right upper lobe resection on day 9 of life. Histology confirmed CCAM but closer examination also showed ACD. Postoperatively pulmonary hypertension persisted despite high-frequency oscillation and inhaled nitric oxide, and she was placed on extracorporeal membrane oxygenation. Due to the lack of any improvement, intensive care treatment was withdrawn 4 days later.

CONCLUSIONS

This is the first description of an association between these two rare malformations. Although a causative link between CCAM and ACD is possible, it is unlikely. ACD should always be considered as a cause of severe PPHN when persistent beyond 10 days, even if another etiology of PPHN is present.

Cystic adenomatoid malformation in children: CT histopathological correlation

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Type I pleuropulmonary blastoma: a report from the International Pleuropulmonary Blastoma Registry

PURPOSE

Type I pleuropulmonary blastoma (PPB) is a rare, cystic lung neoplasm in infants characterized by subtle malignant changes and a good prognosis. Recurrences after type I PPB are usually advanced type II or type III neoplasms with a poor prognosis. This article describes the first collection of type I PPB cases, analyzes outcome based on treatments of surgery or surgery plus chemotherapy, and presents type I PPB management recommendations.

PATIENTS AND METHODS

Type I PPB cases from the International PPB Registry and literature were evaluated using standard statistical methods for outcomes based on age at diagnosis, sex, thoracic side, surgical extent, length of follow-up, constitutional/familial disease, pre-existing lung cysts, intrathoracic findings, and treatments (surgery or surgery and chemotherapy).

RESULTS

Thirty-eight type I PPB cases were identified: Registry (n = 30) and literature (n = 8). Twenty children had surgery alone; eight (40%) experienced recurrence; and four died. Eighteen children had surgery and adjuvant chemotherapy; one experienced recurrence and died. All recurrences were type II or III PPB. Recurrence-free survival was higher in the surgery + chemotherapy group (P = .01); overall survival did not differ (P = .18). The improved recurrence-free survival was found only in males. Four of nine children with recurrence survived.

CONCLUSION

Adjuvant chemotherapy appears to benefit type I PPB patients. Benefit limited to males requires broader substantiation. Salvage after types II and III recurrence is poor (four of nine; 44%). A rigorous surveillance schedule after type I PPB diagnosis might detect early recurrence and be an acceptable alternative to adjuvant chemotherapy.