1/87. Clonal chromosomal changes in juxta-articular myxoma.cytogenetic analysis of a juxta-articular myxoma revealed two distinct cytogenetically abnormal cell populations: inv(2)(p15q36) and 7, t(8;22)(q11-12; q12-13). These clonal chromosomal changes, the first to be reported in this tumour type, suggest that at least some juxta-articular myxomas are neoplastic rather than reactive in nature.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/87. Identification of multiple copies of a 20q-chromosome in a case of myelodysplastic syndrome: a FISH study.In myelodysplastic syndromes (MDS) karyotypic aberrations identify subgroups of patients with distinct clinical-morphological features and can be relevant in risk assessment of developing leukemia. Often conventional cytogenetic analysis is not sufficiently informative due to the presence of partially or completely unrecognizable chromosome markers. By chromosome microdissection (MD) and fluorescence in situ hybridization (FISH) we investigated the nature of a karyotypic marker occurring in multiple copies in one case of MDS arisen in a patient previously treated for breast cancer. Results showed dicentrics derived from telomeric fusion between interstitially deleted 20q-chromosomes. The abnormal karyotype resulted into polysomy for a deleted chromosome 20q.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/87. Collagenous fibroma (desmoplastic fibroblastoma): genetic link with fibroma of tendon sheath?We observed clonal chromosome abnormalities in two fibrous soft tissue tumors diagnosed as collagenous fibroma (desmoplastic fibroblastoma). The involvement of the same band of the long arm of chromosome 11, 11q12, was observed in both tumors. The presence of hitherto unreported similar chromosomal abnormalities in this tumor supports the neoplastic nature of this lesion. In addition, a possible relationship with fibroma of tendon sheath, which also shows rearrangement of 11q12, is suggested. 11q12 might be a common genetic denominator of benign fibroblastic lesions, such as collagenous fibroma and fibroma of tendon sheath.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/87. Coexistence of inverted Y, chromosome 15p and abnormal phenotype.In this study, we report conventional and molecular cytogenetic studies in a patient with multiple anomalies who is a carrier of a pericentric inversion on chromosome Y and a chromosome 15p . His parents were phenotypically normal. The father is a carrier of a pericentric inversion of chromosome Y, and the mother carries a large chromosome 15p variant. The inverted y chromosome was demonstrated by GTG- and CBG-banding, and DAPI-staining. The presence of extra chromosomal material on the chromosome 15p, that was C-band and DAPI positive, was demonstrated by trypsin G-banding. This suggests that the extra chromosomal material contained repetitive dna sequences. NOR-staining indicated the presence a nuclear organizer region at the junction of the chromosome 15p material. fluorescence in situ hybridization (FISH), with chromosome X and Y painting probes, alpha- and classic-satellite probes specific for chromosome Y, alpha- and beta-satellite III probes for chromosome 15 were used to elucidate the nature of both the inverted y chromosome and chromosome 15p . The result with chromosome X and Y painting probes, alpha-satellite, classic-satellite, and DYS59 probes specific for chromosome Y revealed the rearrangement of the y chromosome was an inv(Y)(p11.2q11.22 or q11.23). FISH with alpha-satellite and beta-satellite III probes for chromosome 15 demonstrated that the extra chromosomal material on the chromosome 15 probably represents beta-satellite III sequences. The possible roles of the simultaneous occurrence of an inverted Y and the amplified dna sequence on chromosome 15p in the abnormal phenotype of the proband are discussed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/87. Morphologically normal, CD30-negative b-lymphocytes with chromosome aberrations in classical Hodgkin's disease: the progenitor cell of the malignant clone?A recent study observed that numerical chromosome abnormalities in Hodgkin's disease (HD) are detected not only in morphologically abnormal Hodgkin/reed-sternberg cells, but also in a fraction of morphologically normal cells. However, the phenotypic constitution of these genetically abnormal, morphologically normal cells and their relationship to the malignant Hodgkin/reed-sternberg cells could not be established in the earlier cases studied, because of the low frequency of these cells. The present study investigated two cases of classical Hodgkin's disease containing a relatively large population of such apparently normal cells with aberrant chromosome copy numbers. The phenotype and their position within the developmental route of the malignant compartment were examined by a combined in situ hybridization and immunocytochemistry approach. Numerical abnormalities for chromosome 1 in one case and for chromosomes X, Y, and 1 in the other case were observed not only in CD30-positive Hodgkin/reed-sternberg cells, but also in CD30-negative, morphologically normal cells. It was shown that these genetically aberrant cells expressed the B-cell antigen CD19, thus confirming their B-cell nature. These studies indicate a relationship between the genome aberrations in these genetically abnormal, morphologically normal B-cells and the Hodgkin/reed-sternberg cells, suggesting that they are progenitor cells of the malignant cell fraction.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/87. Heteromorphism 18ph : with or without reproductive consequences?Heteromorphism or chromosomal variants are usually attributed to structural variations in constitutive heterochromatin. In the case of chromosome 18, 25 cases of 18ph have been reported to date. Using the Primed In Situ Labelling technique (PRINS) to study 2 new cases of 18ph , we have been able to confirm their molecular nature and assuming a mechanism of formation. Although such chromosomal variants are usually thought to have no adverse clinical consequence, a review of the literature shows that many cases were diagnosed because of recurrent abortion, malformed or mentally retarded children suggesting the possible relationship between 18ph and such clinical outcomes.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/87. Cutaneous sclerosing Pacinian-like perineurioma.AIMS: The term perineurioma has been used to designate a variety of clinically and histologically different proliferations of perineurial cells based on immunohistochemical and/or ultrastructural characterization. There are two different groups of neoplasms derived from perineurial cells: extraneural or soft tissue perineuriomas, and intraneural perineuriomas. Recently, a sclerosing variant of cutaneous perineurioma has been described. methods AND RESULTS: We report a case of a cutaneous form of perineurioma, combining features of the intraneural and sclerosing varieties, as well as showing a Pacinian pattern of growth. In order to assess the neoplastic nature of the lesion, we performed fluorescence in-situ hybridization (FISH) analysis using a probe which maps to the chromosome band 22q11 and 22q13, allowing us to show deletion or loss of one chromosome 22 in the tumour cells. CONCLUSIONS: This case may be considered a new variant of perineurioma with Pacinian-like features, for which we propose the designation 'sclerosing Pacinian-like perineurioma'.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/87. Thymic sarcomatoid carcinoma with skeletal muscle differentiation: report of two cases, one with cytogenetic analysis.AIMS: Malignant thymic tumour histologically resembling a soft tissue sarcoma is extremely rare and defined as sarcomatoid carcinoma in the recent world health organization (WHO) classification. We report two such cases in which the tumour cells showed a prominent rhabdomyoblastic differentiation and analyse whether these tumours retain an epithelial nature at least in part. methods AND RESULTS: One tumour occurred in a 51-year-old man (Case 1) and the other in a 40-year-old woman (Case 2). Microscopically, both tumours consisted essentially of two types of tumour cells: spindle and large round cells, with no apparent epithelial components. Osteosarcomatous small foci were also found in Case 2. Immunohistochemically, desmin and muscle-specific actin were positive in the majority of both types of tumour cells, whereas myogenin was predominant in the spindle cells and myoglobin in the large round cells. Some of both types of cells expressed cytokeratin with co-expression of myoglobin in the large round cells, but with no myogenin in the spindle cells. Some cytokeratin-positive spindle cells were also negative for desmin. Ultrastructural examination of a recurrent tumour in Case 2 revealed some epithelial features among the spindle cells. Cytogenetic study of the same tumour showed a complex abnormality including der(16)t(1;16)(q12;q12.1), an identical pattern previously reported in a case of thymic squamous cell carcinoma. CONCLUSIONS: The findings support the definition in the WHO classification of sarcomatoid carcinoma that includes purely sarcomatous tumour as in the present cases. Occurrence of this type of tumour may indicate a relationship between thymic epithelial cells and myoid cells and/or a potential for divergent differentiation in thymic epithelial tumours.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/87. Relationship between chromosomal changes complexity and disease aggressiveness in myeloid and lymphoid disorders.In this paper are presented four cases, with unusual chromosomal abnormalities, identified at the first presentation, among over 100 patients with myeloid and lymphoid acute and chronic leukemias cytogenetically investigated. The complexity and nature of cytogenetic abnormalities was in direct relationship with the disease evolution. The first case, a 22 years old man with acute lymphoblastic leukemia type L3, exhibited many structural changes in bone marrow cells with diploid number of chromosomes: del(3)(q26); del (5)(p13); t(8;14) (q24;q32); del(9)(p11q11);inv(15)(p12qter). The second case, a 62 years old woman, diagnosed as poorly differentiated acute leukemia, refractory to treatment, showed hiperdiploidy (48-54 chromosomes) and 3-4 markers derived from chromosomes 5 and 12. The third case, a young man of 27 years old, diagnosed as acute myeloid leukemia, apart of philadelphia chromosome, presented trisomy 16, both in diploid and aneuploid cells. None of these three patients did respond to any medical therapy. Their rapid death was a powerful proof of the correlation between the complexity of genome changes and disease aggressiveness. In the fourth case, a constitutional translocation t(3;5)(q26.3;q21) identified in a 72 years old woman with essential thrombocythemia, appeared not to be involved in the etiology of the disease. In this case, the treatment with hydroxyurea was successful and the disease evolution was favourable. In conclusion, we appreciate that in the three cases of myeloid and lymphoid leukemias it was a direct relationship between the complexity of genomic changes and the aggressiveness of the disease.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/87. Blastoid mantle cell lymphoma: evidence for nonrandom cytogenetic abnormalities additional to t(11;14) and generation of a mouse model.Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32), which is associated with cyclin d1 hyperexpression and a poor prognosis. MCL cases have been shown to progress to a more aggressive disease but the molecular events responsible of this phenomenon have not been determined. We have established two cell lines from the pleural effusions of two patients with MCL that we have used for further cytogenetic characterization to better define the incidence and nature of secondary chromosome abnormalities using multicolor fluorescence in situ hybridization, whole chromosome paint, and specific probes. Both cell lines grew independently without growth factors. Using CCND1/IGH-specific probes, patient UPN1 was found to have a masked t(11;14). Numerous and complex chromosomal abnormalities were found in both cell lines affecting chromosomes 2, 8, 13, 18, 22, X, and Y. These abnormalities included 8p losses, suggesting the presence of an anti-oncogene in this region, rearrangements of 8q24, MYC gene, and translocations involving 8, X, and Y chromosomes, which might be significant in the pathogenesis of MCL progression. The use of the cell lines (UPN1) allowed us to generate a mouse model of human MCL, mimicking a disseminated lymphoma and leading to the death of the animals in 4 weeks. This blastoid MCL model could be of major interest to determine molecular events involved in MCL progression, allowing isolation of involved genes and their functional characterization, and to study the effects of new chemotherapy regimens in mouse models.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
| | Next -> |