1/8. Cytogenetic-clinicopathologic correlations in rhabdomyosarcoma: a report of five cases.rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children younger than the age of 15 years. Histologically, RMS can be subdivided into two major subtypes; embryonal (E-RMS) and alveolar (A-RMS) rhabdomyosarcoma, with E-RMS being the more common. Although cytogenetic and molecular genetic findings have been reported extensively for RMS, clinicopathologic-genetic correlations among these tumors have not been reported in detail. In this report, we correlate the cytogenetic findings, including fluorescence in situ hybridization and spectral karyotyping, with pathologic findings and outcome for five RMS, including two A-RMS, one E-RMS, one botryoid RMS, and one anaplastic nonclassified RMS (N-RMS). The findings in A-RMS and E-RMS generally were consistent with previous reports; however, gain of chromosome 7 in A-RMS and gain of chromosome 9 segments in E-RMS observed here have seldom been reported in the literature. Importantly, the botryoid RMS had a cytogenetic profile similar to other types of E-RMS. An add(11)(q21) observed in this tumor, together with a t(8;11)(q12 approximately 13;q21) reported previously, indicates that 11q21 rearrangements may be nonrandomly related to botryoid RMS. In addition, the N-RMS expressed a cytogenetic pattern similar to that observed in E-RMS, thus providing genetic evidence that anaplastic N-RMS is a variant of E-RMS. Finally, these cases provide cogent evidence for the diagnostic and prognostic significance of the pathologic-genetic classification of RMS.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/8. adult sclerosing rhabdomyosarcoma: cytogenetic link with embryonal rhabdomyosarcoma.Rhabdomyosarcomas are classified into three well-defined categories: embryonal, alveolar and pleomorphic rhabdomyosarcoma. Recently, seven cases of an unusual adult type of rhabdomyosarcoma with a prominent hyaline sclerosis have been described. We report the hitherto unreported cytogenetic changes of an adult sclerosing rhabdomyosarcoma. A 79-year-old woman underwent an amputation for a rapidly growing soft tissue mass in the anterior compartment of the right lower leg. The tumor infiltrated the tibia. On histology, a fascicular spindle to round cell proliferation, embedded in a prominent hyaline matrix, was seen. immunohistochemistry showed focal desmin, myogenin and MyOD1 expression, and electron microscopy revealed Z-band material. cytogenetic analysis disclosed a 44-49,XX, del(1)(p22)[2], 11, 16[5], 18[12], 21[3],-22 [cp13] karyotype. Using fluorescent in situ hybridization (FISH) analysis, the tumor cells were negative for FOXO1A-disrupting translocations specific for alveolar rhabdomyosarcoma. The chromosomal composition of malignant cells resembled the pattern of numerical changes frequently observed in embryonal rhabdomyosarcoma, suggesting a close relationship of an adult sclerosing rhabdomyosarcoma with this entity.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/8. CGH evaluation of two de novo synchronous tumors in a child with a germline p53 mutation.We report the case of a child who developed two de novo synchronous tumors: an osteosarcoma and an embryonal rhabdomyosarcoma. The patient was determined to be a de novo carrier of a P53 germline mutation. comparative genomic hybridization (CGH) analysis revealed that each of the neoplasms was characterized by a specific set of chromosomal imbalances and high-level amplification (HLA) regions. Our CGH findings provide evidence that cancer development is a cellular/organ specific event.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/8. Deregulation of the hedgehog signalling pathway: a possible role for the PTCH and SUFU genes in human rhabdomyoma and rhabdomyosarcoma development.The naevoid basal cell carcinoma syndrome (NBCCS) is caused by mutations in the hedgehog receptor PTCH gene. It is characterized by developmental defects and a predisposition to the development of certain tumours, such as basal cell carcinoma, medulloblastoma and meningioma, and potentially fetal rhabdomyomas and embryonal rhabdomyosarcomas. This study aimed to analyse PTCH status in an NBCCS patient with fetal rhabdomyoma and to investigate whether deregulation of hedgehog signalling, as shown by altered expression of hedgehog pathway components and/or genetic imbalances, is a general finding in sporadic rhabdomyomas and rhabdomyosarcomas. The NBCCS patient had a novel PTCH germ-line mutation, 1370insT, and developed a fetal rhabdomyoma that harboured a 30 bp in-frame deletion in the second allele resulting in homozygous inactivation of PTCH. Sporadic rhabdomyomas and rhabdomyosarcomas showed overexpression of PTCH (43/43) and GLI1 (41/43) mRNA, as determined by in situ hybridization, indicating ongoing active hedgehog signalling. Immunohistochemical staining revealed a subgroup of fetal rhabdomyomas and embryonal rhabdomyosarcomas (12/34) lacking PTCH immunoreactivity. Four of nine informative fetal rhabdomyomas and embryonal rhabdomyosarcomas showed loss of heterozygosity (LOH) in the PTCH region with two of these (one fetal rhabdomyoma and one embryonal rhabdomyosarcoma) also showing LOH in the SUFU region. These findings suggest that haploinsufficiency for the two tumour suppressor genes PTCH and SUFU, which are both active in the same signalling pathway, may be important for tumour development. Based on our results we propose that the pathogenesis of rhabdomyoblastic tumours, particularly fetal rhabdomyomas and embryonal rhabdomyosarcomas, involves deregulation of the hedgehog signalling pathway.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/8. Molecular analysis of a patient with beckwith-wiedemann syndrome, rhabdomyosarcoma and renal cell carcinoma.We described a patient with beckwith-wiedemann syndrome associated with rhabdomyosarcoma (RMS), and renal cell carcinoma (RCC). Karyotypes of peripheral lymphocytes and RMS cells were normal. DNA analyses showed maternal loss of heterozygosity (LOH) at 11p15 region in RMS but not in RCC. The insulin-like growth factor ii gene (IGF2) was found to be expressed at a moderate level in RMS but not in RCC by in situ hybridization. Each of parental allele-derived IGF2 transcript was detected in RCC, while maternal allele-derived transcript was weak in RMS because of maternal LOH. These results suggest that (1) loss of imprinting (LOI) of IGF2 might be responsible for BWS, (2) on the other hand, LOI itself might not induce tumor occurrence in tissues where the control of tissue-specific expression of IGF2 is maintained, (3) increased expression of IGF2 due to maternal loss of a putative controller gene for IGF2 at 11p15 might predispose to sustaining tumorigenic mutations and tumor progression, (4) loss of a putative onco-suppressor gene at 11p15 might induce RMS occurrence. The cause of RCC was thought to be different from that of RMS.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/8. Detection of aneuploidy and possible deletion in paraffin-embedded rhabdomyosarcoma cells with FISH.Conventional cytogenetic studies of solid tumors are limited by the difficulty of culturing tumor cells, while in situ hybridization using paraffin sections of interphase cells results in too many truncated cells. To solve these problems, fluorescent in situ hybridization (FISH) technique was used on free nuclei isolated from formalin-fixed paraffin-embedded embryonal rhabdomyosarcoma (RMS) tissue using our modification of Hedley's method for isolation of nuclei. Biotinylated dna probes for the centromeric regions of chromosomes 6, 8, 11, 12, 17, and 18, painting probes for chromosomes 8 and 11, and a cosmid probe for the HER-2/neu oncogene, were used. The centromeric probes worked well, demonstrating two copies of chromosomes 6, 17, and 18, but three copies of chromosome 11 in 52.9% of nuclei. Four copies of chromosome 8 were observed in 57.1% of nuclei and five or more in 17.1%. Chromosome 12 demonstrated 21.8% trisomy and 62.2% tetrasomy. Painting probes for chromosome 11 also worked well and matched the results of the centromeric probes, with no suggestion of structural aberration. However, the results of the painting probe for chromosome 8 yielded fluorescent areas of different sizes, suggesting that some of the extra chromosomes 8 could be deleted. The cosmid probe for the HER-2/neu oncogene also worked well, and revealed two signals in each nucleus without evidence of amplification. This study illustrates the successful use of a new technique for studying chromosomal aberration in paraffin-embedded solid tumors. The importance of this technique is that it has not been previously possible to use painting probes or cosmid probes on paraffin tissue sections. Use of this procedure will broaden the type of retrospective studies that can be performed to include detection of deletions or translocations.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
7/8. A novel site of DNA amplification on chromosome 1p32-33 in a rhabdomyosarcoma revealed by comparative genomic hybridization.cytogenetic analysis of a human embryonal rhabdomyosarcoma revealed a near-diploid karyotype with structural chromosome aberrations not involving the typical rearrangements of rhabdomyosarcomas, plus a large number of double minutes. comparative genomic hybridization revealed a previously undescribed site of DNA amplification on the short arm of chromosome 1 (band 1p32-33).- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
8/8. rhabdomyosarcoma with rhabdoid-like features.We describe an unusual case of a rhabdomyosarcoma (RMS) in that it had rhabdoid-like cells histologically and occurred in a female who had undergone bone marrow transplantation for chronic myelogenous leukemia. The tumor was composed of loosely cohesive cells with abundant eosinophilic cytoplasm and exhibited PAS-negative paranuclear inclusions. The tumor cells had positive vimentin, muscle-specific actin, sarcomeric actin and desmin immunoreactivity. Ultrastructurally, the tumor cells contained aggregates of thin and thick filaments. in situ hybridization did not detect human papillomavirus or cytomegalovirus DNA, or EBV DNA or rna. The tumor fulfilled the current criteria for a diagnosis of RMS; however, it could not be further classified. The tumor appears to have a good prognosis as there has been no evidence of recurrence five years after resection. As this is the first case report, to our knowledge, of this type of tumor following bone marrow transplant, the significance of this association is not yet clear.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |