Pleuropulmonary blastoma (pulmonary blastoma of childhood): genetic link with other embryonal malignancies?

Strong Expression and Amplification of IGF1R in Pleuropulmonary Blastomas

Pleuropulmonary blastoma (PPB) is a rare malignant intrathoracic tumor primarily affecting children under 5 years of age. PPBs are histologically divided into 3 subtypes: Type 1 PPBs are composed of multiple cysts, and type 3 is a solid lesion with a variable morphologic appearance. Type 2 has a mixed morphology consisting of cystic and solid areas. The genetics of PPB are poorly understood. We analyzed 16 cases of the Kiel Paediatric Tumor Registry with the diagnosis of PPB by comparative genomic hybridization and confirmed some genetic changes by fluorescence in situ hybridization. Furthermore, we performed immunohistochemistry to evaluate insulin-like growth factor type 1 (IGF1R) protein expression. Frequent findings by comparative genomic hybridization were losses on 4q, 5q, 9p and gains on chromosome 8, 17, and 20q. Genomic amplification was observed in 5 cases, 4 related to 15q25qter and 1 to 1p. Fluorescence in situ hybridization could confirm 7 gains of chromosome 8 (7/16, 44%) and 4 amplifications of the IGF1R-gene on 15q26 (4/16, 25%). All of the tumors with IGF1R amplification were type 3 PPBs. One of the PPBs with gain of chromosome 8 was a type 2 tumor and 6 tumors were type 3 PPBs. All but one PPB showed an IGF1R expression by immunohistochemistry. In our series of 16 PPBs, 25% of the tumors have an amplification of the IGF1R gene and 44% show a gain of chromosome 8. All of the tumors with IGF1R amplification were PPBs type 3, indicating that it is a later event in tumor progression, while the gain of chromosome 8 was found in both type 2 and type 3 tumors indicating that these changes are probably earlier events in tumor development. Furthermore, the strong IGF1R protein expression could be a possible therapeutic target in refractory chemoresistant PPBs.

Rhabdoid Tumor Predisposition Syndrome and Pleuropulmonary Blastoma Syndrome

In recent years, hereditary cancer syndromes have developed greater interest in the scientific community. Two such syndromes, rhabdoid tumor syndrome and pleuropulmonary blastoma (DICER1) syndrome, have appeared increasingly in the literature. This review will discuss these two syndromes in terms of clinical parameters, associated tumors, and genetic associations.

DICER1 mutations in embryonal rhabdomyosarcomas from children with and without familial PPB-tumor predisposition syndrome

Embryonal rhabdomyosarcoma (ERMS) is the most common childhood sarcoma and is a component of the familial pleuropulmonary blastoma (PPB)-predisposition syndrome. Using the PPB model, we hypothesized that DICER1 mutations would be found in familial and sporadic forms of ERMS. Blood samples from four children with familial PPB and ERMS, and 52 sporadic ERMS tumors were tested for DICER1 mutations. Germline DICER1 mutations were found in all four patients with familial PPB and 2 of 52 (3.8%) sporadic ERMS had somatic mutations. Our findings confirm the pathogenetic relationship between ERMS and PPB suggesting that ERMS may result from abnormal miRNA regulation.

High therapeutic effectiveness of postoperative irinotecan chemotherapy in a typical case of radiographically and pathologically diagnosed pleuropulmonary blastoma

A 2-year 9-month-old girl with a large mass in the right chest underwent middle and inferior lobectomy, after which the mass was pathologically diagnosed as a pleuropulmonary blastoma (PPB). The clinical, radiographic, and pathologic findings were typical. Three courses of postoperative chemotherapy with 2 different regimens were ineffective in preventing multiple metastases of the lung. We then instituted a protocol with irinotecan (CPT-11) and vincristine. After the third course of this protocol the metastases disappeared and there were no recurrences. PPB is a rare pediatric malignant tumor, and no adequate therapy has been defined. This is the only case reported to have been treated with vincristine/irinotecan therapy for the treatment of PPB.

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.

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.

Cerebral metastasis and other central nervous system complications of pleuropulmonary blastoma

BACKGROUND

Pleuropulmonary blastoma (PPB) is a rare tumor of pleura and lung in young children. Central nervous system (CNS) complications, particularly cerebral parenchymal metastases, occur in aggressive forms of PPB: Types II and III PPB. This article evaluates cerebral and meningeal metastases, cerebrovascular events (CVA) caused by tumor emboli, spinal cord complications, and intracranial second malignancies in PPB.

PROCEDURE

International PPB Registry and literature cases were evaluated for CNS events. Cerebral metastasis patients were evaluated for gender, side of origin of PPB, PPB Type, interval from diagnosis to metastasis, status of chest disease, treatment, and outcome. Standard statistical methods were used to calculate the cumulative probability of cerebral metastasis and survival following metastasis.

RESULTS

Thirty-nine cases of cerebral metastasis were identified in 5/53 Registry Type II cases, 15/44 Registry Type III cases, and 19/143 literature Type II/III cases. Metastases occurred 1-60, median 11.5 months after diagnosis. Chest disease was controlled in 50% of children at time of metastasis. The cumulative probability of cerebral metastasis by 5 years from diagnosis was 11% for Type II patients (95%CI (confidence interval): 2-20%) and 54% for Type III patients (95%CI: 31-76%). Seven children survive cerebral metastasis. Other CNS complications were post-operative CVA (five cases), spinal cord invasion or compression (six), leptomeningeal disease (three), and second intracranial malignancies (two).

CONCLUSIONS

Cerebral metastasis is more frequent in PPB than in other childhood sarcomas. Clinicians should screen for this complication. Diverse other CNS complications are less common and require careful diagnosis.

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.

Hidden chromosomal abnormalities in pleuropulmonary blastomas identified by multiplex FISH

Background

Pleuropulmonary blastoma (PPB) is a rare childhood dysontogenetic intrathoracic neoplasm associated with an unfavourable clinical behaviour.

Cases presentation

We report pathological and cytogenetic findings in two cases of PPB at initial diagnosis and recurrence. Both tumors were classified as type III pneumoblastoma and histological findings were similar at diagnosis and relapse. In both cases, conventional cytogenetic techniques revealed complex numerical and structural chromosomal abnormalities. Molecular cytogenetic analysis (interphase/metaphase FISH and multicolor FISH) identified accurately chromosomal aberrations. In one case, TP53 gene deletion was detected on metaphase FISH. To date, only few cytogenetic data have been published about PPB.

Conclusion

The PPB genetic profile remains to be established and compared to others embryonal neoplasia. Our cytogenetic data are discussed reviewing cytogenetics PPBs published cases, illustrating the contribution of multicolor FISH in order to identify pathogenetically important recurrent aberrations in PPB.

Comparative genomic hybridization analysis of a pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare, aggressive dysontogenetic tumor of childhood. We report the comparative genomic hybridization (CGH) study performed on a case of PPB in a 3-year-old-boy. The tumor was characterized by several chromosomal imbalances. Gains observed affected regions: 1q12-q23, 3q23-qter, 8pter-q24.1, 9p13-q21, 17p12-p11, 17q11-q22, 17q23-q25, 19pter-p11, and 19q11-q13.3. Whole chromosome gains were detected at 2 and 7. Loss of genetic material was found at regions: 6q13-qter, 10pter-p13, 10q22-qter, and 20p13. To our knowledge, there have been no CGH reports on PPB, but it is interesting to note that 1) the alterations found confirm previous cytogenetic reports describing gains of chromosomes 2 and 8 as recurrent abnormalities in this type of tumor, suggesting that a gene or genes of putative relevance in PPB pathogenesis are mapped at 8p11-p12, and 2) the CGH profile of this case is very similar to those observed in embryonal rhabdomyosarcomas, in which gains of 2 or 2q, 7 or 7q, and 8 or 8p and loss of 10q22-qter are consistently found. This finding supports the hypothesis that PPB may be tumorigenetically related with embryonal rhabdomyosarcoma.

Molecular cytogenetic analysis of a pleuropulmonary blastoma

We report a case of pleuropulmonary blastoma with complex cytogenetic abnormalities, including trisomy 2, trisomy 8, dup(7), der(10) t(8; 10)(q13; q22), add(17), and double minutes (dmin). Fluorescence in situ hybridization FISH analysis demonstrated TP53 deletion and amplification of MYCN; the latter has not been reported in PPB.

Use of multicolor spectral karyotyping in genetic analysis of pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare, malignant intrathoracic pediatric tumor. It arises from the lung, pleura, or mediastinum and its pathogenesis and relationship to other pediatric solid tumors is not well understood. In this study, a case of PPB in a 3-year-old girl was studied using a combination of molecular genetic methods and cytogenetics. Molecular analysis of the commonly encountered fusion translocation gene products of pediatric solid tumors failed to detect a rearrangement. Cytogenetic analysis, supplemented by multicolor spectral karyotyping (SKY), identified an unbalanced translocation between chromosomes 1 and X, resulting in additional copies of 1q, an extra copy of Xq, and loss of part of Xp. In addition, trisomy 8 was detected. The identification of new chromosomal alterations and confirmation of previously reported ones in this rare neoplasm helps to improve our understanding of its pathogenesis and association with other pediatric tumors.

Survival with combined modality therapy after intracerebral recurrence of pleuropulmonary blastoma

BACKGROUND

We present and discuss the successful treatment of pleuropulmonary blastoma metastatic to the brain using a multimodality regimen with surgery, high-dose chemotherapy and radiation therapy.

PROCEDURE

A 3-year-old boy referred to our institution with bilateral pulmonary cysts was diagnosed with pleuropulmonary blastoma (PPB). Initial treatment included surgery and multiagent chemotherapy with vincristine, dactinomycin, cyclophosphamide, cisplatin, and doxorubicin. One year after the completion of therapy, his PPB recurred as an intracerebral metastasis, and required further treatment with a multimodality salvage regimen. The child was successfully treated with a subtotal surgical resection, followed by high-dose cyclophosphamide, and radiation therapy. He is now disease-free 24 months later.

RESULTS

Intracerebral metastases of PPB have been a uniformly fatal complication of this tumor. Postsurgical chemotherapy and radiation therapy appear to have contributed to the prolonged survival and potential for cure in our patient.

CONCLUSIONS

The use of this multimodality regimen may be warranted in other patients with recurrent PPB metastatic to the brain.

Pleuropulmonary blastoma: fluorescence in situ hybridization analysis indicating trisomy 2

We report a case of pleuropulmonary blastoma occurring in the right upper lobe and pleura of a 29-month-old boy. Histologically, the tumor was composed of undifferentiated mesenchymal cells with occasional rhabdomyoblastic and chondroid differentiation. Immunohistochemical analysis showed vimentin immunoreactivity in most of the tumor cells, myoglobin, desmin, and actin in the rhabdoid cells, and S-100 protein in the chondroid cells. Fluorescence in situ hybridization (FISH) analysis showed trisomy 2 and normal chromosomal copy numbers for chromosomes 7, 12, 17, 18, and X in the majority of the tumor cell nuclei. The identification of trisomy 2 in the current pleuropulmonary blastoma confirms a previous cytogenetic finding of chromosome 2 abnormality with cultured metaphase cells of a similar case, indicating that the acquisition of an additional chromosome 2 copy in pleuropulmonary blastoma is a nonrandom chromosomal alteration and that pleuropulmonary blastoma is cytogenetically distinct from pulmonary blastoma in which chromosome 2 is bisomic. It is also suggested that pleuropulmonary blastoma may have an intimate tumorigenetic relationship with embryonal rhabdomyosarcoma.

A rare tumor masquerading as an empyema: pleuropulmonary blastoma

Pleuropulmonary blastoma, although rare, should be considered in the differential diagnosis of children who present with a pleural effusion and symptoms of respiratory tract infection when the empyema fails to respond to medical management. A case of a 2-year-old boy with this rapidly growing tumor is reported. The treatment and outcome of pleuropulmonary blastoma in children is reviewed.

Dedifferentiated cystic nephroma with malignant mesenchymoma as the dedifferentiated component

Cystic tumors of the kidney are uncommon and usually do not have solid areas. We report a predominantly cystic renal tumor with solid anaplastic component showing rhabdomyoblastic and cartilaginous differentiation in a 26-month-old girl. Terminology and pathogenesis of tumor progression are discussed along with a review of reports of tumors associated with cystic nephroma.

Pleuropulmonary blastoma: a marker for familial disease

OBJECTIVE

To catalog and evaluate patterns of disease in families of children with pleuropulmonary blastoma (PPB).

METHODS

Data have been collected since 1988 on 45 children with PPB and their families. All pathologic materials were centrally reviewed. Preliminary molecular genetic analyses were performed when possible.

RESULTS

In 12 of 45 patients, an association was found between PPB and other dysplasias, neoplasias, or malignancies in the patients with or in their young relatives. The diseases found to be associated with PPB include other cases of PPB, pulmonary cysts, cystic nephromas, sarcomas, medulloblastomas, thyroid dysplasias and neoplasias, malignant germ cell tumors, Hodgkin disease, leukemia, and Langerhans cell histiocytosis. Abnormalities of the p53 tumor suppressor gene, Wilms tumor suppressor gene (WT1), and the putative second genetic locus for Wilms tumor (WT2) were not found in preliminary investigations.

CONCLUSIONS

The occurrence of PPB appears to herald a constitutional and heritable predisposition to dysplastic or neoplastic disease in approximately 25% of cases. All patients with PPB and their families should be investigated carefully. Further research of this new family cancer syndrome may provide insight into the genetic basis of these diseases.