Use of multicolor spectral karyotyping in genetic analysis of pleuropulmonary blastoma

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.

Primary and metastatic lung tumors in the pediatric population: a review and 25-year experience at a large children's hospital

CONTEXT

Primary lung neoplasms are rare in children, but they comprise a broad and interesting spectrum of lesions, some of which are familiar from other tissue sites, and some of which are unique to the pediatric lung.

OBJECTIVE

To determine the relative incidence of primary and metastatic lung tumors in children and adolescents through a single-institution case series, to compare these data to reports in the medical literature, to discuss the clinical and pathologic features of primary tumors of the tracheobronchial tree and lung parenchyma in children, and to provide recommendations for handling pediatric lung cysts and tumors.

DATA SOURCES

A 25-year single institutional experience with pediatric lung tumors, based on surgical biopsies and resections at Texas Children's Hospital from June 1982 to May 2007, an additional 40 lung tumors referred in consultation, and a review of the medical literature.

CONCLUSIONS

A total of 204 pediatric lung tumors were diagnosed at our institution, including 20 primary benign lesions (9.8%), 14 primary malignant lesions (6.9%), and 170 secondary lung lesions (83.3%). The ratio of primary benign to primary malignant to secondary malignant neoplasms is 1.4:1:11.6. The common types of lung cancer in adults are exceptional occurrences in the pediatric population. The most common primary lung malignancies in children are pleuropulmonary blastoma and carcinoid tumor. Other primary pediatric lung tumors include congenital peribronchial myofibroblastic tumor and other myofibroblastic lesions, sarcomas, carcinoma, and mesothelioma. Children with primary or acquired immunodeficiency are at risk for Epstein-Barr virus-related smooth muscle tumors, lymphoma, and lymphoproliferative disorders. Metastatic lung tumors are relatively common in children and also comprise a spectrum of neoplasia distinct from the adult population.

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.

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.

Spectral karyotyping of human, mouse, rat and ape chromosomes--applications for genetic diagnostics and research

Spectral karyotyping (SKY) is a widely used methodology to identify genetic aberrations. Multicolor fluorescence in situ hybridization using chromosome painting probes in individual colors for all metaphase chromosomes at once is combined with a unique spectral measurement and analysis system to automatically classify normal and aberrant chromosomes. Based on countless studies and investigations in many laboratories worldwide, numerous new chromosome translocations and other aberrations have been identified in clinical and tumor cytogenetics. Thus, gene identification studies have been facilitated resulting in the dissection of tumor development and progression. For example, different translocation partners of the TEL/ETV6 transcription factor that is specially required for hematopoiesis within the bone marrow were identified. Also, the correct classification of complex karyotypes of solid tumors supports the prognostication of cancer patients. Important accomplishments for patients with genetic diseases, leukemias and lymphomas, mesenchymal tumors and solid cancers are summarized and exemplified. Furthermore, studies of disease mechanisms such as centromeric DNA breakage, DNA double strand break repair, telomere shortening and radiation-induced neoplastic transformation have been accompanied by SKY analyses. Besides the hybridization of human chromosomes, mouse karyotyping has also contributed to the comprehensive characterization of mouse models of human disease and for gene therapy studies.

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.

An association of pleuropulmonary blastoma and cystic nephroma: possible genetic association

The association of pleuropulmonary blastoma and cystic nephroma is an uncommon entity, with only 4 cases of such an association in the same patient described in English literature. We report a 5th histologically documented case in a 32-month-old boy. The boy underwent a pulmonary biopsy that showed a pleuropulmonary blastoma and a nephrectomy that showed a cystic nephroma. The pleuropulmonary mass showed an important regression with postbiopsy chemotherapy, allowing subsequent tumorectomy. To date very little is known about this rare entity, and a genetic link between these 2 tumors is hypothesized.

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.

Advances in the detection of chromosomal aberrations using spectral karyotyping

Spectral karyotyping (SKY) is a powerful 24-color, whole chromosome-painting assay allowing the visualization of each chromosome in one experiment. Subtle karyotype rearrangements can be detected easily so that small translocations lead to a transition from one color to another at the chromosomal breakpoint region. SKY has enabled the elucidation of several examples of hidden or "cryptic" structural aberrations that may otherwise have been left undetected by classical cytogenetic methods. Furthermore, the chromosomal origins of abnormalities once designated "marker chromosomes" can now be determined rather than left unidentified. SKY analysis of cancer cytogenetics samples provides a much more detailed description of the highly abnormal karyotypes that characterize advanced tumors and cancer cell lines. In addition, SKY significantly adds to the power of clinical cytogenetic analysis of constitutional chromosomal aberrations by facilitating the identification of subtle structural rearrangements that may contain aneuploidy with potential pathological consequences.