Biomedical subjects

A Peydró-Olaya

Publications and source records attributed to A Peydró-Olaya.

12 recordsLinked to original sources

PubMed2000

Soft tissue Ewing sarcoma--peripheral primitive neuroectodermal tumor with atypical clear cell pattern shows a new type of EWS-FEV fusion transcript.

This study describes a new case of Ewing sarcoma (ES)-peripheral primitive neuroectodermal tumor (pPNET) with unusual phenotype and fusion gene structure. The tumor located in the inguinal area of a 15-year-old boy showed a highly aggressive behavior with hematogenous metastases after intensive chemotherapy and bone marrow transplant, causing death 28 months after diagnosis. The tumor displayed a clear cell pattern, and several neuroectodermal markers proved positive both in the original tumor and in xenografts. This neuroectodermal character was confirmed by electron microscopy. Moreover, cytogenetically the tumor has an unusual chromosomal rearrangement, t(2;22)(q13;q22,t(3;18)(p21;q23); representing a new EWS-FEV fusion type in which exon 7 of EWS gene is fused with exon 2 of FEV gene. This is the third published study of an ES-pPNET showing EWS-FEV fusion described, but it is the first study of a tumor with the aforementioned fusion points. These findings support the genetic and morphologic heterogeneity existing within the group of ES-pPNET tumors.

Adolescent↗

PubMed1999

Near-haploidy in a malignant sacrococcygeal teratoma.

Cytogenetic analysis of a malignant sacrococcygeal teratoma in an adult patient revealed near-haploid (77%), near-diploid (19%), and polyploid (4%) cells. The near-haploid cells had a karyotype of 25,XX,der(5)t(5;7)(p15;p13),+7,der(9)t(6;9)(p21;q34),r(17)(p13q25) . In the near-diploid and polyploid cells identical copies of the structural chromosomal changes were found. Although some of the anomalies observed appear unique to this case, a common breakpoint in chromosome 6 was previously reported as specific in a subgroup of extragonadal germ cell tumors of adults.

Aged↗

PubMed1998

Translocation (X;18) in a biphasic synovial sarcoma with morphologic features of neural differentiation.

The authors report a recurred neoplasm showing distinctive histologic, immunophenotypic, and ultrastructural features characteristic of biphasic synovial sarcoma with neural differentiation. The features include areas with a growth pattern of densely packed spindle cells in irregularly intersecting, broad fascicles, diffuse vimentin and HBA 71 immunoreactivity, expression of S-100 protein, and other neural markers. Moreover, areas with glandular structures and cellular expression of cytokeratin and epithelial membrane antigen were noted. Additionally, areas of neural-like growth pattern were positive for neuron-specific enolase, HNK-1, and protein gene product 9.5. Furthermore, cytogenetic analysis, two-color interphase fluorescence in situ hybridization, and reverse transcription polymerase chain reaction demonstrated the reciprocal translocation between chromosomes X and 18 associated with the different subtypes of tumor cells. The establishment and characterization of the tumor cell line are detailed. This cell line retains the distinct morphologic and genetic characteristics of the original biphasic synovial sarcoma with neural differentiation.

Adult↗

PubMed1997

Bipolar (neural and myoblastic) phenotype in cell lines derived from human germ cell tumours of testis.

Non-seminomatous germ cell tumours of the testis (NSGCT) form a heterogeneous group of neoplasms. Cell lines derived from NSGCT may provide useful data concerning the biology of neoplasic precursor germ cells, differentiation of tumour stem cells and the relationship between various tissue components of these tumours. Four NSGCT were studied, two mixed tumours composed of teratocarcinoma, yolk sac and trophoblastic elements, and two malignant teratomas with a massive neuroectodermal component, equivalent to primary neuroectodermal tumours (PNET) of the testis. The explanted tumours gave rise to various cell populations, including epitheloid cells, flattened large cells, spindle cells and tear drop cells of neuroblastic type. Ultrastructurally, cultured cells expressed various degrees of neural and muscular differentiation: neurosecretory granules, intermediate filaments of glial nature, and filaments resembling Z-bands. Cultured cells showed the expression of several neural and muscular markers, including neurofilaments, cytokeratin, actin, desmin, neuron-specific enolase, glial fibrillary acidic protein and HNK-1. In addition, three cases expressed HBA-71 antigen and two expressed MyoD1 protein. All cases were aneuploid, and an isochromosome 12p, i(12p), was detected in three cases. Myoblastic and neural cells are the predominant tumour cells that grow in vitro, independent of the nature and composition of the primary germ cell tumour. A histogenetic relationship between germ cell tumours and small round cell tumours of childhood is suggested.

Adult↗

PubMed1997

Molecular alterations of the RB1, TP53, and MDM2 genes in primary and xenografted human osteosarcomas.

We report the status of the RB1, TP53, and MDM2 genes in human osteosarcomas and cell lines established from surgical specimens and transplanted into athymic naked mice. By using reverse transcriptase-polymerase chain reaction (RT-PCR) as a prescreening technique and posterior sequencing, we observe new mutations in the RB1 gene, notably a duplication in tandem of exons 3 through 6. TP53 mutations appear in codons most frequently mutated in osteosarcomas. We have not seen MDM2 gene amplification in any reported case. These molecular alterations appear in different osteosarcomas not simultaneously present in the same tumor sample. A link has been described between these three genes in the pathways that control the cell cycle and the tumoral progression, but their functions are probably independent in the development of osteosarcomas. TP53 mutations appear in adult patients, whereas RB1 alterations occur mostly in younger patients.

Adolescent↗

PubMed1995

Small round cell tumors of bone and soft tissue. A morphometric and stereometric comparative analysis of 119 cases.

OBJECTIVE: To analyze the discriminative capability of morphometric assessment of nuclear morphology in the differential diagnosis of small round blue cell tumors (SRCTs) of bone and soft tissue. STUDY DESIGN: The study material consisted of glutaraldehyde-fixed, resin-embedded, semithin sections from 119 human tumors. Nuclear area, perimeter, maximum diameter, form factors and nuclear density were measured in at least 300 nuclei per case. RESULTS: Neuroblastoma (NB) (10 cases) showed the most regular pattern. Ewing's sarcoma (ES) (35 cases); atypical Ewing's sarcoma (AEs) (15 cases) and peripheral neuroectodermal tumors (PNET) (30 cases) showed no significant differences regarding area, perimeter or form factors, but AEs showed a lower mean nuclear density that was statistically significant. Rhabdomyosarcomas (6 cases) and osteosarcomas (OS) (11 cases) were used as controls and showed several morphometric and stereometric differences with other SRCTs, whereas microcellular OSs (6 cases) shared features of SRCTs and conventional osteosarcomas. CONCLUSION: Morphometric characterization of nuclear features reveals differences between the distinct groups of SRCTs. Although overlapping occurred between all these groups at the individual case level, this study provides new support for the existence of morphologic links within the family of ES and PNET.

Bone Neoplasms↗

PubMed1994

Patterns of differentiation in extraosseous Ewing's sarcoma cells. An in vitro study.

BACKGROUND: In vitro, tissue culture-associated differentiation assays have facilitated the identification of multiple tumor-cell types. METHODS: We have investigated the capability of differentiation of three extraosseous Ewing's sarcoma cell lines toward a neural and muscular direction by in vitro stimulation with dibutyryl cyclic adenosine-monophosphate (db cAMP) and 5-azacytidine, respectively. RESULTS: Elongation of cytoplasmic processes and increase of neural markers chromogranin, S-100 protein, and glial fibrillary acidic protein were observed after db cAMP treatment of these lines and neurosecretory granules as well as myelin figures were demonstrated ultrastructurally. These results support the existence of several pathways of neural differentiation in vitro--neuroblastic, Schwannian, and central glial--in stages of maturation more advanced than those previously reported in Ewing's sarcoma of bone. The cell lines showed no definitive myoblastic differentiation after 5-azacytidine treatment. CONCLUSIONS: These data suggest that these three extraosseous Ewing's sarcoma cell lines configurate a heterogeneous group of tumors with respect to capability of differentiation into the neural lineage, arrested at more advanced stages of neural crest development than Ewing's sarcoma of bone and without capability of myoblastic differentiation with 5-azacytidine.

Abdominal Neoplasms↗

PubMed1994

Morphological and immunohistochemical support for the interstitial cell origin of oestrogen-induced kidney tumours in the Syrian golden hamster.

The oestrogen-induced kidney tumour of the Syrian golden hamster has been extensively used not only as a model for renal carcinogenesis, but also for hormonal carcinogenetic studies. In spite of all the different approaches, its histogenesis remains unresolved. The two classical hypotheses are an epithelial origin (in the proximal convoluted tubules) or a mesenchymal-blastemal origin (in the interstitial cells). In the present study two types of preneoplastic lesions were seen: tubular dysplasia and interstitial cell hyperplasia. The first neoplastic stage consisted of interstitial or blastemal cells aggregated in the form of microscopic nodules (tumourlets). In the more advanced tumours the blastemal pattern was the more predominant, but we also observed other patterns of epithelial, mesenchymal or neural types. These findings were confirmed by ultrastructural analysis, which revealed blastemal-epithelial transitions and mesenchymal and mesonephric features, as well as the presence of neurosecretory granules. The paucity of immunohistochemical studies on these tumours led us to apply a panel of the most frequently used antibodies in diagnostic pathology to 36 cases of our series. There was co-expression of cytokeratins and vimentin, which were the most intensely stained, together with S-100 protein. Further positivities were seen for carcinoembryonic antigen, desmin, neuron-specific enolase and HNK-1. These results lend support to the revised, new histological classification confirmed by the ultrastructural findings, allowing us to postulate a tumoural origin in the renal interstitial cells, which may be nephrogenic undifferentiated cells that possess an epithelial, mesenchymal and neuroectodermal phenotype.

Animals↗

PubMed1993

Case of meningioma with del(1)(p32) as sole anomaly.

We studied a case of typical syncytial meningioma. Cytogenetic analysis of the tumor cells showed a karyotype with normal chromosomes 22 and only one anomaly, del(1)(p32). Cases of meningiomas with normal chromosomes 22 and other anomalies are rare, and it is difficult to correlate their histologic characteristics and biologic behavior.

Adult↗

PubMed1989

Malignant myxoid liposarcoma: an immunohistochemical, electron-microscopical and cytogenetical analysis.

We discuss the morphological, immunohistochemical and electron-microscopical features of a malignant myxoid liposarcoma which appeared in the left thigh of a 52-year-old woman. The cytogenetic analysis following short-term tissue culture confirmed the existence of a nonrandom translocation t(12;16)(q13;p11). Furthermore, immunohistochemistry showed positivity for S-100 antigen and vimentin, both of which are considered to be markers for liposarcoma. The electron-microscopical study revealed a close contiguity between the tumoral cells and atypical pericytes.

Biomarkers, Tumor↗

PubMedDate not supplied

[Differential immunohistochemical characteristics of meningiomas and other neoplasms of the central nervous system].

We present an immunohistochemical study of 16 meningiomas and 19 CNS tumors including gliomas, neurinomas and metastatic carcinomas, in order to establish a histopathologic differential diagnosis, using formalin-fixed and paraffin-embedded material. The antibodies analysed included vimentin, GFA-protein, cytokeratin, S-100 protein and epithelial membrane antigen. Meningiomas always express vimentin as marker, and occasionally cytokeratin and EMA. The most constant antigens demonstrated in astrocytomas were GFA-protein and vimentin, and occasionally we were able to detect S-100 protein. Neurinomas proved positive to S-100 protein, and metastases presented cytokeratin and EMA reactivity. Our results confirm the existence of diverse immunohistochemical patterns within CNS tumors, a fact that can be useful in routine differential diagnosis.

Astrocytoma↗

PubMedDate not supplied

[Retinoblastoma: morphologic, ultrastructural and scanning electron microscopy study].

We present a clinical and morphological study of one case of unilateral Retinoblastoma in a boy two years of age. There were no family antecedents. Cellular morphology and histological organization were studied with particular reference to rosettes and the angiogenic capacity of the tumor. Scanning electron microscopy permitted the definition of the surface organization and infiltration pattern together with tridimensional characteristics of the Rosettes. We also discuss the neuroectodermal origin of the neoplasm.

Child, Preschool↗