Prognostic factors in pleuro-pulmonary blastoma

Patient Characteristics, Treatment, and Survival in Pleuropulmonary Blastoma: An Analysis from the National Cancer Database

Pleuropulmonary blastoma (PPB) is a rare childhood tumor originating from the lung or pleura, typically treated with surgery, chemotherapy (CTx), and/or radiation therapy (RTx). This study aimed to assess patient and tumor features, treatment methods, and survival rates in PPB. We retrospectively analyzed PPB patients under 18 from 2004 to 2019, using the National Cancer Database (NCDB). We assessed 5-year overall survival (OS) rates based on disease presentation and treatment regimens, using Kaplan-Meier curves and Cox proportional regression. Among 144 cases identified, 45.9% were female, with a median age of 2 years (interquartile range 1-3). In all, 62.5% of tumors originated from the lung, and 10.4% from the pleura. Moreover, 6.9% were bilateral, and the median tumor size was 8.9 cm, with 4.2% presenting with metastases. The 5-year OS rate was 79.6%, with no significant change over time (2004-2009, 77.6%; 2010-2014, 90.8%; 2015-2019, OS 75.3%; p = 0.08). In all, 5.6% received CTx alone, 31.3% surgery alone, 45.8% surgery/CTx, and 17.4% surgery/CTx/RTx. The OS rates were comparable between the surgery/CTx/RTx (80.0%) and surgery/CTx (76.5%) groups (adjusted Hazard Ratio, 1.72; 95% CI, 0.57-5.19; p = 0.34). Therefore, due to the unchanged survival rates over time, further prospective multicenter studies are needed to determine the optimal multimodal treatment regimens for this rare pediatric tumor.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry

PURPOSE

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis.

METHODS

Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort.

RESULTS

From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively.

CONCLUSION

The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.

A rare case of pleuropulmonary blastoma detected in fetus

Pleuropulmonary blastoma (PPB) is among the rarest malignant tumors diagnosed in children. PPBs can be histopathologically classified into 3 types: cystic tumor (type I), mixed cystic and solid tumor (type II), and pure solid tumor (type III). We describe a case of type III PPB that was detected in a prenatal fetus, confirmed using histopathological methods. To the best of our knowledge, this is the first case describing a type III PPB detected in a fetus. Prenatal ultrasonography is an excellent tool for detecting pulmonary lesions during the diagnostic phase, and the possibility of PPB should be considered when solid tumors are detected. Early detection can allow for the performance of full resection, leading to a better prognosis for this cancerous tumor.

Accuracy of Chest Computed Tomography in Distinguishing Cystic Pleuropulmonary Blastoma From Benign Congenital Lung Malformations in Children

IMPORTANCE

The ability of computed tomography (CT) to distinguish between benign congenital lung malformations and malignant cystic pleuropulmonary blastomas (PPBs) is unclear.

OBJECTIVE

To assess whether chest CT can detect malignant tumors among postnatally detected lung lesions in children.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective multicenter case-control study used a consortium database of 521 pathologically confirmed primary lung lesions from January 1, 2009, through December 31, 2015, to assess diagnostic accuracy. Preoperative CT scans of children with cystic PPB (cases) were selected and age-matched with CT scans from patients with postnatally detected congenital lung malformations (controls). Statistical analysis was performed from January 18 to September 6, 2020. Preoperative CT scans were interpreted independently by 9 experienced pediatric radiologists in a blinded fashion and analyzed from January 24, 2019, to September 6, 2020.

MAIN OUTCOMES AND MEASURES

Accuracy, sensitivity, and specificity of CT in correctly identifying children with malignant tumors.

RESULTS

Among 477 CT scans identified (282 boys [59%]; median age at CT, 3.6 months [IQR, 1.2-7.2 months]; median age at resection, 6.9 months [IQR, 4.2-12.8 months]), 40 cases were extensively reviewed; 9 cases (23%) had pathologically confirmed cystic PPB. The median age at CT was 7.3 months (IQR, 2.9-22.4 months), and median age at resection was 8.7 months (IQR, 5.0-24.4 months). The sensitivity of CT for detecting PPB was 58%, and the specificity was 83%. High suspicion for malignancy correlated with PPB pathology (odds ratio, 13.5; 95% CI, 2.7-67.3; P = .002). There was poor interrater reliability (κ = 0.36 [range, 0.06-0.64]; P < .001) and no significant difference in specific imaging characteristics between PPB and benign cystic lesions. The overall accuracy rate for distinguishing benign vs malignant lesions was 81%.

CONCLUSIONS AND RELEVANCE

This study suggests that chest CT, the current criterion standard imaging modality to assess the lung parenchyma, may not accurately and reliably distinguish PPB from benign congenital lung malformations in children. In any cystic lung lesion without a prenatal diagnosis, operative management to confirm pathologic diagnosis is warranted.

Intraventricular topotecan in the successful treatment of recurrent CNS pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare pediatric tumor of the pleura and pulmonary mesenchyme, associated with pathogenic germline DICER1 mutations. Although the most common site of metastasis is the central nervous system (CNS), patients with CNS metastasis have dismal outcome. We report a case of a patient presenting with type II PPB and intracranial and bone metastases. We describe a multimodal therapy approach and highlight the use of intraventricular topotecan for isolated CNS recurrence. In addition, a new pathogenic germline mutation heterozygous for the c.1234delT of DICER1 was identified. Patient remains in remission 3 years after recurrence.

Pleuropulmonary Blastoma (PPB) in Child with DICER1 Mutation: The First Case Report in the State of Qatar

Pleuropulmonary blastoma (PPB) is a rare intrathoracic malignancy, which arises from the lung parenchyma and/or pleura. PPB has strong genetic association with mutations in DICER1 gene. Despite being rare, PPB is the most common lung tumor in children below 6 years of age. International registry of the disease has a total of 350 cases worldwide. We report the first case of PPB in the state of Qatar, which presented as a large cystic lung lesion. The patient was first thought to have benign congenital pulmonary airway malformation (CPAM) based on chest X-ray findings. The diagnosis of PPB was suspected based on chest CT scan findings and was confirmed after surgical resection of the cystic mass. The case highlights the need to consider PPB in the differential diagnosis of cystic lung lesions in children and the need for further radiological imaging (i.e., CT scan), genetic testing, and/or excisional biopsy to confirm the diagnosis.

Pleuropulmonary blastoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Pleuropulmonary blastoma (PPB) is a rare cancer occurring mainly during early childhood and often associated with germline DICER1 mutations. It is classified by the macroscopic appearance into three interrelated clinico-pathologic entities on a developmental continuum. Complete tumor resection is a main prognostic factor and can be performed at diagnosis or after neoadjuvant treatment that includes chemotherapy and in some cases radiotherapy. Optimal modalities of neo- or adjuvant treatments can be challenging taking into account potential long-term toxicities in this young population. This paper presents the recommendations for diagnosis and treatment of children and adolescents with PPB elaborated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the European Union-funded project PARTNER (Paediatric Rare Tumours Network - European Registry).

Type II Pleuropulmonary Blastoma in a 4 Month Old Infant with Negative Dicer1 Mutation on Next Generation Sequencing

INTRODUCTION

Pleuropulmonary blastoma (PPB) is a rare, but aggressive tumor in the pediatric population. PPB is a dysontogenetic neoplasm of childhood that involves the lungs and/or pleura. Young relatives of children with PPB have an increased incidence of neoplasias and dysplasias. According to tumor tissue histopathology, PPB evolves from a cystic to solid state over time. PPBs can be sub-classified as type I (purely cystic), type II (having both cystic and solid elements), and type III (completely solid). Type II and type III tumors may be associated with metastasis, with the brain being the most common metastatic site. Due to the primitive nature of cells in the tumor mass, PPBs are very aggressive tumors that are resistant to therapy. The prognosis depends on the histopathology content and tumor type. Respiratory problems are the main complaint and diagnosis can be made only after additional examinations. Genetic relations through family members are associated with mutations in the DICER1 gene; between 60-80% of patients with PPBs are positive for DICER1 mutations. Mosaicism has also been reported.

AIM

The aim was to present a case of a 4 month-old infant with type II PPB, who had a negative result for DICER1 mutation in next generation sequencing. To detail the clinical presentation of this patient, we present radiographic and ultrasound findings and results of histopathological analysis, as well as genetic and scintigraphic findings and chemotherapy treatment.

CASE REPORT

Here we describe the genetic analysis of a patient with PPB who was negative for mutations in DICER1 and who had no relatives with disease. This patient underwent radical resection of the tumor and began therapy, but subsequently died after developing leukopenia and sepsis.

CONCLUSION

This case provides an example of a patient with PPB who was negative for DICER1 mutation upon genetic analysis and emphasizes the potential for disease that does not involve mutation of this gene.

The Effect of Gross Total Resection on Patients with Pleuropulmonary Blastoma

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common primary lung cancer in children. While rare, these tumors are highly aggressive. Tumor recurrence and overall survival are dependent on histologic grade and extent of surgical resection. We sought to examine our institutional experience with PPB to determine the effect of gross total resection (GTR) on recurrence and patient outcomes.

MATERIALS AND METHODS

After IRB approval, a retrospective chart review from 1998 to 2018 was performed. Cases were confirmed by histology and Dehner Grade (I to III). Data collection included demographics, treatment, extent of surgical resection, and patient outcomes.

RESULTS

Eight patients with nine procedures were identified. Histologically, three cases were type 1, 2 type 2, and four poor prognosis type 3. Three patients received neoadjuvant chemotherapy to facilitate surgical resection. The operative goal was to achieve GTR (>95%), and to this end, three partial lobectomies, five lobectomies, and one pneumonectomy were performed. All nine cases achieved GTR, of which eight had negative microscopic margins. Two patients with type III disease recurred (one locally, one distant) and died. One type 3 patient had a positive microscopic hilar margin not amenable to further resection. The patient recurred (distant) but is in remission. With respect to patient outcomes, the event-free survival was 2.3 y with an overall survival of 3.3 y.

CONCLUSIONS

From our experience, GTR of PPB is associated with minimal surgical morbidity and good overall survival. Multi-institutional studies are needed to determine if positive surgical margins affect outcomes given the morbidity of mediastinal dissection.

Pleuropulmonary blastoma: a report from the TREP (Tumori Rari in Età Pediatrica) Project

INTRODUCTION

Pleuropulmonary blastoma (PPB) is a rare, aggressive mesenchymal tumor of childhood. The Italian Tumori Rari in Età Pediatrica (TREP) Registry was the first in Europe dedicated to prospective data collection on rare pediatric tumors. We analyzed data from an Italian series of patients with PPB, focusing on the role of the TREP Project.

METHODS

We considered patients aged 0-14 with histologically confirmed diagnosis, registered in population-based cancer registries (before 2000) or the TREP Registry (2000 to 2014), and analyzed data on clinical characteristics, treatment, and outcome. Event-free survival (EFS) and overall survival (OS) were estimated. Relevant prognostic factors were identified performing a univariate analysis.

RESULTS

Thirty-seven cases were included (7 type I, 13 type II, 17 type III). The average diagnosis rate rose from 1.10 to 1.73 cases/year after the TREP Project started. All patients underwent surgery, 33 received chemotherapy, and 9 had radiotherapy. The median follow-up was 8.7 years. For type I, II, and III, respectively, the 5-year OS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 57.8% (31.1-77.3); the 5-year EFS was 85.7% (33.4-97.9), 52.7% (23.4-75.5), and 52.9% (27.6-73.0). Favorable prognostic factors for EFS were Intergroup Rhabdomyosarcoma Study (IRS) stage I (p = 0.03) and T1 tumor (p = 0.05). A total of 78.3% of patients who had chemotherapy after 2000 received a standardized treatment.

CONCLUSIONS

The TREP Registry showed an excellent capacity for registering cases of PPB. Patients received homogeneous treatment after the TREP Project started. Long-term outcomes were excellent for type I and unsatisfactory for type II and III. Tumor invasiveness and IRS stage were of prognostic value.

Diagnosis and treatment of pleuropulmonary blastoma-single center experience

Pleuropulmonary blastoma (PPB) is a rare and potentially aggressive intrathoracic disembryonic neoplasm typically occurring in children less than 6 years of age. We assessed the relative incidence, clinical characteristics, treatment outcome, and the prognostic factors for long-term survival in patients with PPB treated at our institution over a 25-year period, and compared these data with reports in the literature. From 1985 to 2010, 11 children (4 males and 7 females), with a median age of 5.4 years (range, 1-12 years) were treated at our hospital. Here we described the main characteristics of these patients, the diagnostic methods, and treatment modalities used. During a median follow-up period of 80, 9 months, the overall survival (OS) and disease-free survival (DFS) rates were 54, 6% and 45, 5%, respectively. Two patients survived for more than 20 years. The main prognostic factors for long-term survival were the diseases type I and II and treatment with radical surgery. Our results show that in order to improve the prognosis of patients with PPB a timely in our opinion and accurate diagnosis needs to be established and treatment should be offered according to the disease type and extend of dissemination.

Pleuropulmonary blastoma: a report on 350 central pathology-confirmed pleuropulmonary blastoma cases by the International Pleuropulmonary Blastoma Registry

BACKGROUND

Pleuropulmonary blastoma (PPB) has 3 subtypes on a tumor progression pathway ranging from type I (cystic) to type II (cystic/solid) and type III (completely solid). A germline mutation in DICER1 is the genetic cause in the majority of PPB cases.

METHODS

Patients confirmed to have PPB by central pathology review were included, and their clinical characteristics and outcomes were reported. Germline DICER1 mutations were sought with Sanger sequencing.

RESULTS

There were 435 cases, and a central review confirmed 350 cases to be PPB; 85 cases (20%) were another entity. Thirty-three percent of the 350 PPB cases were type I or type I regressed (type Ir), 35% were type II, and 32% were type III or type II/III. The median ages at diagnosis for type I, type II, and type III patients were 8, 35, and 41 months, respectively. The 5-year overall survival (OS) rate for type I/Ir patients was 91%; all deaths in this group were due to progression to type II or III. OS was significantly better for type II versus type III (P = .0061); the 5-year OS rates were 71% and 53%, respectively. Disease-free survival (DFS) was also significantly better for type II versus type III (P = .0002); the 5-year DFS rates were 59% and 37%, respectively. The PPB type was the strongest predictor of outcome. Metastatic disease at the diagnosis of types II and III was also an independent unfavorable prognostic factor. Sixty-six percent of the 97 patients tested had a heterozygous germline DICER1 mutation. In this subset, the DICER1 germline mutation status was not related to the outcome.

CONCLUSIONS

Cystic type I/Ir PPB has a better prognosis than type II, and type II has a better outcome than type III. Surveillance of DICER1 carriers may allow the earlier detection of cystic PPB before its progression to type II or III PPB and thereby improve outcomes.

Type III pleuropulmonary blastoma in a 7-month-old female baby with impending respiratory failure: a case report

Introduction

Pleuropulmonary blastoma is a very rare, aggressive, embryonal pulmonary neoplasm which mostly affects children under the age of 5. According to the histopathological features, three subtypes of pleuropulmonary blastoma have been recognized: type I (purely cystic), type II (grossly visible cystic and solid elements) and type III (purely solid). Characteristics of type I and type II blastoma allow an earlier diagnosis compared with type III. Here we present a case report of an unusual presentation of type III pleuropulmonary blastoma.

Case presentation

We describe the case of a 7-month-old female baby of Italian mother and Kurdish father who was diagnosed with type III pleuropulmonary blastoma, which entirely occupied her right hemithorax.

Conclusions

The reported case is an unusual presentation because type III pleuropulmonary blastoma typically occurs in older children. The complete re-expansion of her residual, previously totally compressed, right lung observed immediately after the resection of the lesion suggests an atypical rapid growth of this embryonal tumor in the late phase of gestation or after delivery. This case report suggests that, in addition to other childhood tumors, type III pleuropulmonary blastoma should be included in the differential diagnosis of solid nonhomogeneous thoracic large masses, compressing the mediastinal and chest wall structures in infants. This is an original case report of interest for several specialities such us pediatrics, radiology, surgery and oncology.

Thoracoscopic lobectomy for type I pleuropulmonary blastoma in an infant

Pleuropulmonary blastoma (PPB) is a rare, aggressive, intrathoracic mesenchymal neoplasm associated with cystic lung lesions. The authors describe an 8-month-old male who underwent thoracoscopic left upper lobectomy for a cystic lung lesion initially diagnosed as congenital pulmonary airway malformation. Pathology revealed type I PPB.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

Pleuropulmonary blastoma as characteristic cause of pneumothorax

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common lung neoplasms in childhood. Usually presents as recurrent respiratory infections and in some cases as pneumothorax.

CASE REPORT

We report the case of a 2-year-old patient that was diagnosed with PPB, that first manifested as recurrent pneumothorax. Three chest computed tomography were necessary for the diagnosis. The first 2 tomographies showed no abnormalities suggestive of malignancy. The patient had a family history of both PPB and leukemia. Three years and a half after completion of treatment, the patient is in complete remission.

CONCLUSIONS

PPB is an uncommon disease but is the most common pulmonary neoplasms in childhood. We must suspect it in patients with a suggestive family history and recurrent pneumothorax in the same location.

[Child pleuropulmonary blastoma]

Pleuropulmonary blastoma is an extremely rare and aggressive thoracic tumour seen exclusively in children. The initial symptoms are respiratory and non specific and the chest X-ray done in that context reveals a thoracic mass. The chest CT scan then leads to the diagnosis of a cystic, mixt or solid mass. The diagnosis will be affirmed on anatomopathology of the tumour or biopsy. There are three different histological types: type I, cystic, type II, cystic and solid and type III, solid exclusively. Type I is less aggressive and its treatment is essentially surgical. Types II and III are highly aggressive and require surgery associated to polychemotherapy. In all cases, surgery is essential and should be the most complete possible. Extension and follow-up exams will include bone scan and brain imagery searching for metastasis as well as abdominal ultrasound searching associated renal lesions because 30% of pleuropulmonary blastoma are part of a familial predisposition syndrome.

[Pleuropulmonary blastoma: a clinicopathological analysis]

背景与目的

胸膜肺母细胞瘤是一种罕见的且有其独特临床病理特征的恶性肿瘤，本文旨在探讨胸膜肺母细胞瘤的临床病理学特点及鉴别诊断等。

方法

收集5例胸膜肺母细胞瘤，复习患者临床资料，进行组织学及免疫组化观察，并结合文献复习分析。

结果

5例胸膜肺母细胞瘤患者年龄为21个月-47个月，平均为32.8个月；肿瘤主要位于胸腔，4例伴有胸腔积液。组织学观察：Ⅰ型胸膜肺母细胞瘤1例，呈单纯囊性；Ⅱ型胸膜肺母细胞瘤2例，呈囊实性，实性区伴横纹肌分化及灶性软骨样结节；Ⅲ型胸膜肺母细胞瘤2例，完全呈实性，可见间变性未分化肉瘤样成分。免疫组化染色显示肿瘤细胞呈Vimentin（+），部分肿瘤细胞呈Desmin和Myogenin（+），软骨样结节呈S-100（+）；PCK、EMA、CD99等均（-）。

结论

胸膜肺母细胞瘤是一种罕见的主要发生于婴幼儿肺和胸膜的高侵袭性恶性肿瘤，各亚型均有其临床病理学特点。诊断方面应与肺先天性囊性腺瘤样畸形、胚胎性横纹肌肉瘤等良恶性病变鉴别。

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.

Thirteen-year-old child with a malignant chest tumor: clinicopathologic conference

A case of pleuropulmonary blastoma in a 13-year-old child, exposed to the Chernobyl disaster while in-utero, is presented and discussed by both clinician and pathologist, in this traditional clinical-pathologic conference. The discussion includes the differential diagnoses of chest mass in children.

Pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a dysontogenetic neoplasm of childhood that involves lung and/or pleura. There is an increased incidence of neoplasias and dysplasias among young relatives of children with PPB. Pathophysiologically, PPB evolves from a cystic to solid state over time. It is subclassified as type I (purely cystic), type II (both cystic and solid elements), and type III (completely solid). Type II and type III may be associated with metastasis, with the brain being the most common metastatic site. The absence of epithelial malignancy in PPB is a feature that distinguishes it from the adult-type pulmonary blastoma. The clinical presentation includes signs and symptoms associated with various respiratory disorders. To make a definitive diagnosis of PPB, an examination of the cystic fluid or solid tumor is required. Treatment for PPB consists primarily of surgery and chemotherapy. Nursing care is directed toward maintaining normal respiratory and neurological function, maintaining normal fluid and electrolyte balance, minimizing side effects associated with treatment, and providing education for the family.

Gain of chromosome 8q is a frequent finding in pleuropulmonary blastoma

Pleuropulmonary blastomas are rare malignant intrathoracic tumors of early childhood. They appear as a pulmonary- and/or pleural-based mass and their pathogenesis and relationship to other pediatric solid tumors is not well understood. In this study, paraffin-embedded material of five cases of pleuropulmonary blastoma was analyzed for genetic alterations by comparative genomic hybridization and five genetic loci by fluorescence in situ hybridization. Comparative genomic hybridization identified aberrations in all pleuropulmonary blastomas, including four amplifications in three tumors at chromosomes 5q33-34, 11q22.2-ter, 15q25-ter, and 19q11-13.2. The most frequent DNA gains involved 8q11-22.2 (four cases) and 20q (two cases), whereas the most common losses included 9p21-24 (two cases) and 11p14 (three cases). Chromosome 8 gains were confirmed by fluorescent in situ hybridization, resulting in the detection of up to five copies of chromosome 8 centromeres per nucleus. In the two surviving patients, chromosome 8 gains were the only genetic abnormality, suggesting that this might be an early event in pleuropulmonary blastoma carcinogenesis. The identification of new genetic alterations as well as the confirmation of previously reported ones (especially 8q gains) in pleuropulmonary blastoma should help to improve our understanding of both the molecular mechanisms underlying the tumorigenesis of pleuropulmonary blastoma and the relationship of pleuropulmonary blastoma with other pediatric tumors.