1/9. Cytogenetic characteristics of a malignant rhabdoid tumor arising from the paravertebral region. A case report.The pathological and cytogenetic features of an extrarenal malignant rhabdoid tumor (MRT) arising from the paravertebral region in an infant were investigated. The patient died 4 months after diagnosis, due to aggressive tumor progression. The tumor was composed of medium-sized round cells with cytoplasm containing eosinophilic inclusions, which ultrastructurally were composed of densely packed whorled intermediate filaments. Flow-cytometric analysis of the tumor cells revealed a diploid pattern. Amplification of the N-myc oncogene was not identified. Immunohistologically, the inclusion bodies showed a positive reaction with antiserum against vimentin. The tumor cells were not reactive with antiserum against epithelial membrane antigen, anti-keratin (polyclonal) or cytokeratin (monoclonal, CK1), but did react with 5H10, an antiserum established from human sarcomatous Wilms' tumor. This case is discussed with reference to the literature on extrarenal MRT, placing stress on the histogenesis of this tumor.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |
2/9. Translocation (1;22)(p36;q11.2) with concurrent del(22)(q11.2) resulted in homozygous deletion of SNF5/INI1 in a newly established cell line derived from extrarenal rhabdoid tumor.Malignant rhabdoid tumor (MRT) is a highly malignant pediatric cancer, which arises in various sites such as the kidney, brain, and soft tissues. Cytogenetic studies have revealed alterations of 22q11 in MRT. Recently, deletions and mutations of the SNF5/INI1 locus in 22q11.2 have been reported in MRT, suggesting that SNF5/INI1 is a tumor suppressor gene for MRT. Here we report our molecular cytogenetic study for a newly established cell line from extrarenal MRT with t(1;22)(p36;q11.2). Consequently, the reciprocal translocation was associated with the interstitial deletion of a small segment including SNF5/INI1, and another, chromosome 22, showed terminal deletion, the breakpoint of which was located 70-80 kb centromeric to SNF5/INI1, resulting in homozygous deletion of SNF5/INI1 in this cell line.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |
3/9. Primary thoracic myxoid variant of extrarenal rhabdoid tumor in childhood.Primary extrarenal rhabdoid tumors (RT) are now recognized as a specific entity in pediatric oncological pathology practice. We present an unusual case of a small cell myxoid variant of a thoracic RT in an infant and highlight the importance of recent molecular developments in the diagnosis of these tumors. An 8-month-old child presented with a short history of cough and shortness of breath. Imaging demonstrated a large mass occupying the majority of the thoracic cavity on the right side. A percutaneous needle biopsy of the mass showed fragments of tissue composed of malignant tumor with a predominant "small ovoid cell" phenotype and extensive myxoid change, with small nests and islands of tumor cells; occasional cells demonstrated open vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasmic inclusions. Immunohistochemical staining revealed focal strong cytoplasmic positivity for cytokeratin, focal strong paranuclear cytoplasmic vimentin positivity, and INI1 staining showed normal nuclear positivity in control tissues but was negative in tumor cell nuclei. Electron microscopy demonstrated characteristic paranuclear whorls of intermediate filaments confirming the diagnosis of extrarenal malignant RT. The diagnosis of malignant rhabdoid tumor may be difficult, particularly in cases, such as the present, with a predominant small-cell myxoid phenotype. The characteristic expression patterns of cytokeratin and vimentin provide strong clues to the diagnosis, and the use of INI1 antibody now makes definitive diagnosis possible even on needle core biopsies.- - - - - - - - - - ranking = 1.2keywords = rhabdoid (Clic here for more details about this article) |
4/9. Malignant rhabdoid tumor of the thoracic spine.A case of malignant rhabdoid tumor of the spine and a description of its CT findings are presented. The CT demonstrated a heterogeneous contrast enhancing epidural mass associated with severe bony destruction of the adjacent vertebra and cord compression.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |
5/9. Extrarenal rhabdoid sarcoma.Rhabdoid sarcoma is a tumor of unknown etiology that usually occurs in the kidneys of infants and small children. We report an adolescent with a rhabdoid sarcoma of the chest wall. In addition to the patient's age and the site of the tumor, other unusual features of this case were as follows: positive staining of tumor cells with neuron-specific enolase, the presence of chronic, active, hepatitis that apparently developed coincident with the sarcoma, and the presence of widespread hemosiderosis. Two of the patient's siblings died in infancy with degenerative neurologic disease, hepatomegaly, and multiple congenital anomalies. The histochemical findings and family history lend support to previous suggestions that some rhabdoid sarcomas may be of neural crest origin and may be heritable lesions.- - - - - - - - - - ranking = 1.2keywords = rhabdoid (Clic here for more details about this article) |
6/9. Vertebral hyperemia associated with bone marrow insult and recovery.A 15-year-old boy with rhabdoid sarcoma received chemotherapy, which was followed by bone marrow depression, massive nosebleeds and, finally, hematologic recovery. On both hepatobiliary and renal scintigraphy, prominent vertebral activity was present in early images. Correlation with his clinical course suggests that the findings reflect hyperemia due to marrow insult and recovery. radionuclide imaging to detect hyperemia may be a useful probe for drug effects on hematopoietic bone marrow.- - - - - - - - - - ranking = 0.2keywords = rhabdoid (Clic here for more details about this article) |
7/9. Small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features of the thoracic wall: a case report with histological, immunohistochemical and ultrastructural examinations.A case of small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features is presented. The tumor was encountered in a 32 year old Japanese woman with an initial presentation of palpable tumor in the left lateral region of the thorax. The resected tumor was a partially well encapsulated whitish medullary one and consisted of small round and spindle tumor cells, together with so-called rhabdoid cells in the small round cell area. Although pseudorosettes were often observed, true rosette formation could not be detected anywhere. Ultrastructurally, despite a histologic variety of tumor cells, most tumor cells possessed numerous mitochondria, some of which occasionally contained abnormal filamentous or crystalloid structures. Various amounts of microfilaments were present in most tumor cells and microtubules were present in a few. A minority of small round cells possessed a small number of neurosecretory granules, especially in short cytoplasmic processes. A positive immunoreaction for neuron specific enolase was found by immunohistochemical examination in several small round tumor cells and for neurofilaments in lesser numbers. Despite the lack of S-100 protein, MB2 was detected in both small round and spindle cells. On the basis of these findings, the tumor of the present case corresponds to malignant peripheral nerve sheath tumor with neuronal differentiation and oncocytic features.- - - - - - - - - - ranking = 0.2keywords = rhabdoid (Clic here for more details about this article) |
8/9. Cytogenetic and molecular analysis of a t(1;22)(p36;q11.2) in a rhabdoid tumor with a putative homozygous deletion of chromosome 22.Malignant rhabdoid tumors are rare and aggressive neoplasms of childhood, occurring in the kidney or in various extrarenal locations. Most cytogenetic studies of these tumors have shown the frequent involvement of chromosome 22, including translocations and/or deletions, with a critical region for a rhabdoid tumor gene mapping to chromosome segment 22q11, close to BCR. We report a case of an extrarenal rhabdoid tumor with a t(1;22)(p36;q11.2) that was associated with deletions of chromosomes 1 and 22. We have performed fluorescence in situ hybridization to bracket the translocation breakpoints on both chromosomes and microsatellite analysis to establish the deletion of chromosome 22 more precisely. The chromosome 22 translocation breakpoint is localized close to BCR, in the region covered by the overlapping YACs 446B5 and 361D9, and it is associated with a proximal hemizygous deletion of approximatively 2 Mb. On chromosome 1, the translocation breakpoint maps to a 25 cM region, proximal to D1Z2 and distal to PND, and is also associated with an estimated deletion of 8 Mb. Moreover, microsatellite analysis has demonstrated a homozygous deletion of chromosome 22 for three contiguous loci, immediately distal to BCR. This result suggests that a tumor suppressor gene involved in rhabdoid tumor oncogenesis could be localized in this region of chromosome 22.- - - - - - - - - - ranking = 1.6keywords = rhabdoid (Clic here for more details about this article) |
9/9. Congenital malignant rhabdoid tumor presenting as a cutaneous nodule: report of 2 cases with review of the literature.OBJECTIVE: The congenital occurrence of malignant rhabdoid tumor (MRT) is rare. Initial presentation of congenital MRT as a skin tumor is even more rare. We report 2 cases in which a cutaneous nodule appeared prior to the discovery of the primary tumor. methods: Histologic, ultrastructural, and immunohistochemical studies were performed on skin nodules from 2 neonates. Other congenital examples of MRT in the literature were reviewed. RESULTS: Both neonates were male and both were fullterm. skin nodules were noted at birth. The tumors were located on the right neck in case 1 and on the right back in case 2. The primary tumors were later found in the kidney and the right chest wall, respectively. The skin biopsy of the first case had been interpreted as undifferentiated sarcoma, and MRT was diagnosed after the renal tumor was examined. In the second case, a correct diagnosis was promptly made based on the skin biopsy owing to experience with the first case. CONCLUSIONS: Congenital MRT is very uncommon and may present as a skin tumor at birth. Since MRT exhibits various histologic patterns, the diagnosis should be made by a complete pathologic study with proper clinical correlation. To our knowledge, the unique mode of manifestation in these 2 cases is described for the first time. We suggest that MRT should be considered when making the differential diagnosis in such a clinical setting.- - - - - - - - - - ranking = 1keywords = rhabdoid (Clic here for more details about this article) |