1/43. Sarcomatoid hepatocellular-carcinoma showing rhabdomyoblastic differentiation in the adult cirrhotic liver.An unusual case of a massive liver tumour composed of rhabdomyosarcoma with a small focus of hepatocellular carcinoma in a 52-year-old man is presented. He had hepatitis b virus (HBV) surface antigen in his serum. Macroscopically, a large tumour with satellite nodules occupied the right lobe of the cirrhotic liver. Microscopically, the tumours were composed of small and short spindle-shaped undifferentiated cells, mixed with desmin-positive round rhabdomyoblasts and elongated striated muscle cells, strongly suggestive of rhabdomyosarcoma of the liver. Elevated levels of alpha-fetoprotein in the serum led us to examine the liver tumour closely in multiple sections, which disclosed a hepatocellular carcinoma component measuring 2 cm in diameter within the massive tumour. Immunohistochemically, the hepatocellular carcinoma cells were alpha-fetoprotein positive. There was neither a tumour capsule, nor distinct demarcation, and cytokeratin-positive clusters of undifferentiated cells were intermingled with the hepatocellular carcinoma and rhabdomyosarcoma at the border. The invading tumour outside the liver and metastatic tumours were pure rhabdomyosarcomas. It is suggested that the present case should be diagnosed as rhabdomyosarcoma transformed from hepatocellular carcinoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/43. rhabdomyosarcoma metastasizing as a malignant ectomesenchymoma.rhabdomyosarcoma is a common childhood malignancy that may occasionally occur as a component of a mixed mesenchymal tumor, e.g., a triton tumor or malignant ectomesenchymoma. A case is reported of a 13-year-old boy who had resection of a paratesticular embryonal rhabdomyosarcoma with subsequent radiation and chemotherapy. Two years later, a retroperitoneal metastasis was resected. histology showed a mixture of rhabdomyoblasts, ganglion cells, and a third population of cells with combined features of these two distinct cell types. Electron microscopy confirmed the presence of rhabdomyoblasts with characteristic bundles of myofilaments and Z-band material, and ganglion cells with prominent nuclei and nucleoli, rough endoplasmic reticulum, dense core granules, filaments, and tubules. Notably, the third cell population showed features of both rhabdomyoblasts and ganglion cells. immunohistochemistry confirmed the mixed population of rhabdomyoblasts (positive for vimentin, desmin, negative for S-100, NSE), ganglion cells (positive for S-100 and NSE, negative for vimentin and desmin), and the third population expressing all test antigens. The features of this metastatic lesion are those of a malignant ectomesenchymoma with combined rhabdomyosarcoma and ganglioneuroma components. It is postulated that this lesion results from biphenotypic expression of tumor cells that previously expressed only rhabdomyoblastic differentiation. The role of prior chemotherapy and radiotherapy in this particular case is unclear.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/43. A new human pleomorphic rhabdomyosarcoma cell-line, HS-RMS-1, exhibiting MyoD1 and myogenin.A number of human cell lines derived from alveolar or embryonal rhabdomyosarcoma (RMS) have been described. To our knowledge, however, no cell line established from pleomorphic RMS has been reported. We describe here the establishment and characterization of a new human cell line, HS-RMS-1, which originated from a typical pleomorphic RMS arising in the gluteal muscle of a 26-year-old man. HS-RMS-1 cells had pseudotetraploid complex karyotypes with no specific abnormalities. Both in vitro and in vivo the cells on light microscopic examination exhibited pleomorphic features with immunopositive reaction for myogenic antigens including MyoD1 and myogenin, although no Z band-like structures were detected electron-microscopically. RT-PCR demonstrated the expression of MyoD1 and myogenin in HS-RMS-1 cells at the mRNA level, and direct sequencing analysis revealed cDNAs of MyoD1 and myogenin identical to those previously reported. This cell line, HS-RMS-1, established from pleomophic RMS will be useful for further studies including the molecular aspects of human RMS.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/43. Tissue-specific expression of SV40 in tumors associated with the li-fraumeni syndrome.Inactivation of wild-type p53 tumor suppressor function is the primary mechanism of tumor initiation in li-fraumeni syndrome (LFS) individuals with germline p53 mutations. Tumors derived from LFS patients frequently retain the normal p53 allele, suggesting that alternative mechanisms in addition to gene deletion must be involved in inactivating wild-type p53 protein. dna tumor viruses, such as SV40, target p53 for inactivation through the action of viral oncoproteins. We studied the probands from two unrelated LFS families, each of whom presented with multiple malignant neoplasms. Patient 1 developed an embryonal rhabdomyosarcoma (RMS) and a choroid plexus carcinoma (CPC), while patient 2 developed a CPC and subsequently presented with both an osteosarcoma (OS) and renal cell carcinoma (RCC). We utilized DNA sequence analysis and immunohistochemistry to determine p53 gene status in the germline and tumors, as well as evidence for SV40 T-antigen oncoprotein expression. Each patient harbored a heterozygous germline p53 mutation at codons 175 and 273, respectively. In patient 1, the normal p53 gene was lost while the mutant p53 allele was reduced to homozygosity in the RMS. Both normal and mutant genes were maintained in the CPC. In patient 2, normal and mutant p53 alleles were retained in both the CPC and RCC. Both specific PCR and immunostaining detected SV40 T-antigen in both CPCs and the RCC. In addition to chromosomal alterations, epigenetic mechanisms may disrupt p53 function during tumorigenesis. In two LFS patients, we found SV40 DNA sequences and viral T-antigen expression that could account for inactivation of the normal p53 protein. Inactivation of p53 or other tumor suppressors by viral proteins may contribute to tumor formation in specific tissues of genetically susceptible individuals.- - - - - - - - - - ranking = 3keywords = antigen (Clic here for more details about this article) |
5/43. Rhabdomyosarcomatous (myoblastic?) phenotype of metastatic malignant melanoma. A case report.melanoma may present a great variety of cell morphology and mimic virtually almost all other neoplasms, and metastatic lesions pose major diagnostic difficulties. A typical immunoreactive profile of melanoma is: S-100p- and HMB-45-positivity, but these markers are not always present. Other new antigens for melanoma are NKIC3 and Anti-Melan-A (MART-1). This tumor may also present expression of unspecific markers, as cytokeratin, CEA, EMA, desmin, NFP, GFAP, CD68 and actins. We present here unusual features of two metastatic melanomas, showing the anaplastic pattern, immunopositive for desmin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/43. An ultrastructural and immunohistochemical study of olfactory neuroepithelioma with rhabdomyoblasts.A rare case of olfactory neuroepithelioma with rhabdomyoblasts in a 61-year-old man was investigated using electron microscopic and immunohistochemical methods. A large tumor enhanced by gadolinium-diethylenetriamine pentaacetic acid (DTPA) was demonstrated on magnetic resonance imaging (MRI), located within the anterior cranial fossa without bone destruction. The tumor mostly consisted of small cells with scant cytoplasm. Tubular rosettes were often found. Immunoreactivity for cytokeratin and epithelial membrane antigen (EMA) was strongly positive. Most of the tumor cells were shown to be positive for neuron-specific enolase (NSE) and vimentin and weakly positive for synaptophysin and S-100. Rhabdomyoblasts, which showed oval cells with abundant eosinophilic cytoplasm and a nucleus sometimes displaced toward the periphery of the cell body, were frequently intermingled with the tumor cells. The immunoreactivity for myoglobin was frequently positive in these oval cells. The MIB-1 index showed high values, of 20%-40%. About 10% of the tumor cells revealed positivity for p53 protein and vascular endothelial growth factor (VEGF). Ultra-structurally, numerous junctional complexes were observed between cell bodies and processes. The cell processes frequently contained numerous microtubules. There were sometimes numerous filaments with small aggregates of Z-band material and thick filament-ribosomal complexes in the oval cells. They were concluded to be consistent with rhabdomyoblasts on light microscopic and immunohistochemical findings.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/43. Malignant rhabdoid tumor of soft tissues: a cytopathological and immunohistochemical study.We describe the cytopathological and immunohistochemical features of a primary malignant rhabdoid tumor (MRT) located in the left forehead region of an 8-mo-old female. The cardinal characteristics are hyaline cytoplasmic inclusions, rounded or bean-shaped nucleus, vesicular chromatin, central prominent nucleolus, and poorly defined cytoplasmic profile. Both the cytoplasm and the hyaline inclusion are vimentin and keratin positive, but negative with desmin, S-100 protein, neuron-specific enolase, (NSE) myoglobin, leukocyte common antigen (LCA), and alpha-1-antichymotrypsin. This immunohistochemical pattern, although not exclusive to MRT, is fairly typical of MRT, and when it is assessed in conjunction with cytopathological findings and clinical data permits a confident diagnosis of MRT. We emphasize the utility of immunohistochemical techniques in making the differential diagnosis of MRT against other childhood round-cell tumors.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/43. rhabdoid tumor of the skin.A tumor in the skin of a 42-year-old man was analyzed by light and electron microscopic study and immunohistochemistry. The tumor cells were large and contained eosinophilic, periodic acid-Schiff (PAS)-positive inclusions in the cytoplasm. Immunohistochemically, the neoplasm was positive for intermediate filaments, cytokeratin, vimentin, desmin, and alpha-1-antichimotrypsin, and negative for S-100 and leukocyte common antigen (LCA). Ultrastructurally, the cytoplasm and cellular processes of the cells were inundated with intermediate filaments, some of which were tightly bundled. Junctional complexes and secretory granules were absent. These features suggest a rhabdoid tumor: a malignant tumor of uncertain origin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/43. Malignant rhabdoid tumor arising from soft parts of the right thigh with unusual neurologic manifestation: report of a case.A case of malignant rhabdoid tumor (MRT) arising from the soft tissue of the right thigh in a 49-year-old Chinese female with peripheral neuropathy is reported. The tumor, exhibiting the salient features of MRT, was composed of sheets and nests of polygonal cells with prominent nucleoli and characteristic paranuclear inclusion-like hyaline globules under light microscopy which corresponded to aggregates of intermediate filaments under electron microscopy. The results of immunohistochemical studies of the tumor cells were also characteristic: cytokeratin ( ), vimentin ( ), epithelial membrane antigen (EMA) ( ), desmin (-), myoglobin (-), leukocyte common antigen (LCA) (-), kappa (-), lambda (-), IgG (-) and IgA (-). Serologic study revealed an M-component of IgA. The clinical evolution of the patient was highly aggressive and inevitably lethal. An adult malignant rhabdoid tumor is unusual, and its association with peripheral neuropathy and the coexistence of an M-component of IgA in this case appears to be unique. In this report, the differential diagnosis of histopathologic features, the association of peripheral neuropathy and the coexistence of an M-component of IgA are discussed.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
10/43. Bilateral metastatic rhabdomyosarcoma to the breast in an adolescent female: touch imprint cytology and implication of MyoD1 nuclear antigen.BACKGROUND: rhabdomyosarcoma accounts for approximately 4% of all childhood malignancies. breast metastases from rhabdomyosarcoma are uncommon with an incidence of 6%. CASE REPORT: We present a patient who developed bilateral mammary metastases from rhabdomyosarcoma arising in the right lower extremity. An 11-year-old female with a 20-month history of rhabdomyosarcoma was referred to our department because of bilateral breast enlargement. A needle core biopsy was performed and touch imprint slides were obtained. Cytology determined the masses to be metastases of rhabdomyosarcoma. MyoD1 immunostain and RT-PCR analysis confirmed the diagnosis. CONCLUSIONS: Cytomorphology with ancillary methods is essential in the diagnosis of metastatic breast deposits in order to avoid unnecessary mastectomy and to employ systemic treatment.- - - - - - - - - - ranking = 4keywords = antigen (Clic here for more details about this article) |
| | Next -> |