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Query: UMLS:C0035412 (rhabdomyosarcoma)
 6,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinicopathologic findings in 200 cases of malignant fibrous histiocytoma (MFH) with follow-up information are presented. This tumor occurred principally as a mass on an extremity (lower extremity 49%, upper extremity 19%) or in the abdominal cavity or retroperitoneum (16%) of adults (peak incidence 61-70 years of age). It typically involved deep fascia (19%) or skeletal muscle (59%) and only rarely was confined to the subcutis without fascial involvement (7%). The MFH had variable morphologic features and frequently showed transitions from areas having a highly ordered storiform pattern to less differentiated areas having a pleomorphic appearance. The rate of local recurrence of the tumor was 44%, and of metastasis, 42%. Metastasis was most frequently to the lung (82%) and lymph nodes (32%). Factors that influenced the rate of metastasis included depth, size, and inflammatory component of the tumor. Tumors that were small, superficially located, or had a prominent inflammatory component metastasized less frequently than larger, more deeply located tumors. In our experience the MFH is the most common soft tissue sarcoma of late adult life, and many tumors previously diagnosed as pleomorphic variants of liposarcoma, fibrosarcoma, or rhabdomyosarcoma are probably examples of MFH. Although the histogenesis of this neoplasm remains controversial, we feel it is best regarded as a primitive and pleomorphic sarcoma showing partial fibroblastic and histiocytic differentiation, as reflected by collagen production and occasional phagocytosis.
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PMID:Malignant fibrous histiocytoma: an analysis of 200 cases. 20 8

An ultrastructural study of pleomorphic liposarcoma with an unusual clinical presentation is described. A 69-year-old Caucasian female presented with recurrent superficial phlebitis of left leg, which responded only partially to conventional therapy. Following investigations, a mass was excised. Diagnosis of pleomorphic liposarcoma was made on microscopic examination. Numerous lipid droplets in the cytoplasm and often within intranuclear extensions of cytoplasm were seen on oil red O stain of frozen sections. Ultrastructural features are quite distinctive. The cells varied from small to often large pleomorphic cells with numerous lipid spaces without limiting membrane, large pleomorphic nuclei, and an abundance of cytoplasmic organelles. Centrioles were very prominent, in close proximity to nuclei, and collections of autophagocytic inclusions. Intercellular collagen was immature and scant. These features are compared to ultrastructural features of malignant fibrous histiocytoma, pleomorphic rhabdomyosarcoma, and cardiac myxoma, indicating that ultrastructural features are distinctive and help differentiate similar soft tissue tumors.
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PMID:Ultrastructural observations in pleomorphic liposarcoma. 21 74

Intracellular collagen was detected by electron microscopy in 14 sarcomas including six osteogenic sarcomas, three liposarcomas, three malignant fibrous histiocytomas, one pleomorphic rhabdomyosarcoma, and one childhood rhabdomyosarcoma. It was contained in not only the fibroblastic cells, but also in the osteoblastic, lipoblastic, myofibroblastic, and primitive cells of the various tumors. The banded intracellular collagen fibrils were observed in large phagocytic vesicles and in smaller membrane-bound vesicles which also appeared to fuse with lysosomes. Residual banding could be seen as well in many such phagolysosomes. Banded collagen was also noted in a primary explant in tissue culture. These findings suggest that the configurations of intracellular collagen seen, are parts of a continuum of a secondary pathway of collagen degradation in mesenchymal tissue and that pathway is one factor indicating a close interrelationship between these sarcomas.
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PMID:Intracellular collagen fibrils in human sarcomas. 21 51

Ultrastructural examination of an alveolar rhabdomyosarcoma revealed that the bulk of the tumor was composed of small polygonal cells containing polyribosomes, short strands of rough endoplasmic reticulum, and variable amounts of glycogen; the cells were joined by small desmosome-like structures. Similar cells, as well as a variety of larger forms which appeared to be derived from the small cells, were observed along the septa; the larger forms developed a copious cytoplasm and occasionally produced myofilaments. Some of these cells were separated from the septa by basement membranes. Giant cells were also present in the alveolar spaces; these formed neither basement membranes nor myofilaments. The septa themselves were composed largely of collagen and fibroblasts. It is suggested that the commonly proposed correspondence of alveolar rhabdomyosarcoma to the myotube stage of muscle differentiation is incorrect; if anything, the overall pattern of the tumor is epithelial-like, and may correspond to the organization of mesenchymal cells at the stage of somite differentiation. The resemblance of the masses of small tumor cells to the cells of Ewing's sarcoma is discussed.
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PMID:Ultrastructural observations on the histogenesis of alveolar rhabdomyosarcoma. 56 50

The ultrastructural and immunohistochemical findings are reported in two ovarian myxomas, one of which was also associated with a sclerosing stromal tumor of the same ovary. Both neoplasms showed a myxoid, moderately cellular proliferation of spindle and stellate cells interspersed with areas of fibrosis and hemorrhage as well as delicate vascular spaces. Ultrastructurally, stellate neoplastic cells with irregular nuclei and occasional nucleoli were embedded in a mucinous and loose collagen matrix. Their cytoplasm showed abundant intracytoplasmic thin filaments that rarely condensed into poorly formed dense bodies. These thin filaments correlated with immunoreactivity for muscle-specific actin and vimentin. The neoplastic cells showed no immunoreactivity with antibodies to desmin, S-100 protein, cytokeratin AE1:AE3, factor VIII-related protein, or placental alkaline phosphatase. These ultrastructural and immunohistochemical findings are consistent with myofibroblastic differentiation. These ancillary studies exclude important, clinically more aggressive differential considerations such as myxoid rhabdomyosarcoma, myxoid liposarcoma, myxoid neural tumors, mucinous adenocarcinoma showing pseudomyxomatous change, and myxoid-appearing endodermal sinus (yolk sac) tumor.
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PMID:Ovarian myxoma: ultrastructural and immunohistochemical findings. 150 39

The transcriptional activity of plasmid pCOL-KT, in which human pro alpha 1 (I) collagen gene upstream sequences up to -804 and most of the first intron (+474 to +1440) drive expression of the chloramphenicol acetyltransferase (CAT) gene [Thompson, Simkevich, Holness, Kang & Raghow (1991) J. Biol. Chem. 266, 2549-2556], was tested in a number of mesenchymal and non-mesenchymal cells. We observed that pCOL-KT was readily expressed in fibroblasts of human (IMR-90 and HFL-1), murine (NIH 3T3) and avian (SL-29) origin and in a human rhabdomyosarcoma cell line (A204), but failed to be expressed in human erythroleukaemia (K562) and rat pheochromocytoma (PC12) cells, indicating that the regulatory elements required for appropriate tissue-specific expression of the human pro alpha 1 (I) collagen gene were present in pCOL-KT. To delineate the nature of cis-acting sequences which determine the tissue specificity of pro alpha 1 (I) collagen gene expression, functional consequences of deletions in the promoter and first intron of pCOL-KT were tested in various cell types by transient expression assays. Cis elements in the promoter-proximal and intronic sequences displayed either a positive or a negative influence depending on the cell type. Thus deletion of fragments using EcoRV (nt -625 to -442 deleted), XbaI (-804 to -331) or SstII (+670 to +1440) resulted in 2-10-fold decreased expression in A204 and HFL-1 cells. The negative influences of deletions in the promoter-proximal sequences was apparently considerably relieved by deleting sequences in the first intron, and the constructs containing the EcoRV/SstII or XbaI/SstII double deletions were expressed to a much greater extent than either of the single deletion constructs. In contrast, the XbaI* deletion (nt -804 to -609), either alone or in combination with the intronic deletion, resulted in very high expression in all cells regardless of their collagen phenotype; the XbaI*/(-SstII) construct, which contained the intronic SstII fragment (+670 to +1440) in the reverse orientation, was not expressed in either mesenchymal or nonmesenchymal cells. Based on these results, we conclude that orientation-dependent interactions between negatively acting 5'-upstream sequences and the first intron determine the mesenchymal cell specificity of human pro alpha 1 (I) collagen gene transcription.
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PMID:The transcriptional tissue specificity of the human pro alpha 1 (I) collagen gene is determined by a negative cis-regulatory element in the promoter. 152 Feb 67

To characterize VLA alpha subunit cytoplasmic domain functions, unaltered alpha 2 cDNA (called X2C2) and two chimeric cDNAs (called X2C5 and X2C4) were constructed with extracellular alpha 2 domains and cytoplasmic alpha 2, alpha 5, and alpha 4 domains respectively. Upon transfection into rhabdomyosarcoma (RD) cells, each construct yielded comparable expression levels, immunoprecipitation profiles, and avidity for collagen and laminin. However, while RDX2C2 and RDX2C5 transfectants mediated collagen gel contraction, RDX2C4 and a mock transfectant (RDpF) did not. Conversely, only RDX2C4 cells (but not RDX2C2 or RDX2C5) showed enhanced cell migration on collagen and laminin compared with RDpF cells. This indicates markedly differing roles for integrin alpha subunit cytoplasmic domains in post-ligand binding events. Furthermore, stable exertion of physical force (collagen gel contraction) may involve fundamentally different cellular machinery than the transient adhesion occurring during cell migration. Finally, these findings provide insight into a functional flexibility perhaps resulting from multiple integrins binding to identical ligands.
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PMID:Distinct cellular functions mediated by different VLA integrin alpha subunit cytoplasmic domains. 154 2

Cell surface receptors for echovirus, a common human pathogen, were identified with monoclonal antibodies that protected susceptible cells from infection with echovirus 1. These monoclonal antibodies, which prevented virus attachment to specific receptor sites, recognized the alpha and beta subunits of the integrin VLA-2 (alpha 2 beta 1), a receptor for collagen and laminin. RD rhabdomyosarcoma cells expressed little VLA-2, did not bind to 35S-labeled virus, and resisted infection until transfected with complementary DNA encoding the alpha 2 subunit of VLA-2. Thus, integrins, adhesion receptors important in interactions between cells and with the extracellular matrix, can mediate virus attachment and infection.
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PMID:Identification of the integrin VLA-2 as a receptor for echovirus 1. 155 54

Eleven cases of proliferative fasciitis and myositis in children, ages 2.5 months to 13 years, are presented. Eight lesions averaging 2.3 cm in size occurred in the extremities, two in the head and neck region and one on the chest wall. Like proliferative fasciitis and myositis in adults, these lesions consisted of admixtures of large polygonal to spindled, ganglion-cell-like fibroblasts with vesicular nuclei and prominent inclusion-like nucleoli. Seven of 11 lesions were initially diagnosed as sarcomas, most commonly rhabdomyosarcoma. Four patients were treated by wide excision (three with regional lymphadenectomy), three received chemotherapy, and one was given radiation therapy. There were some histologic differences from adult-type proliferative fasciitis and myositis. The childhood lesions were generally well circumscribed, lobulated, extremely cellular with less collagen production, and often associated with acute inflammation and microscopic foci of necrosis. Immunohistochemical comparison with adult proliferative fasciitis and myositis showed similar immuneprofiles; the ganglion-like cells stained for vimentin and actin and focally with KP1, suggesting myofibroblastic and histiocytic features. None of the lesions stained for keratin, desmin, or S-100 protein. Ultrastructural examination of two cases revealed cells with a constellation of fibroblastic, myofibroblastic, and histiocytic features. Follow-up of seven patients, averaging 58 months from diagnosis, confirmed that all are alive and well. Recognition of this cellular variant of proliferative fasciitis and myositis is important to prevent misdiagnosis as a sarcoma and unnecessary, excessive therapy.
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PMID:Proliferative fasciitis and myositis of childhood. 156 69

A 1.8-kb cDNA encoding portion of a novel collagenous chain was isolated from a human rhabdomyosarcoma cell line by cross-hybridization using a chicken type V collagen probe. Sequence analysis suggests that this chain belongs to the recently discovered group of collagens, termed the FACIT class of macromolecules. This cDNA was used to locate the corresponding gene (D6S228E) to chromosome 6, notably at position 6q12-q14. Interestingly, within this region of human chromosome 6 residues the alpha 1 (IX) collagen gene (COL9A1), a member of the FACIT group.
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PMID:Synteny between the loci for a novel FACIT-like collagen locus (D6S228E) and alpha 1 (IX) collagen (COL9A1) on 6q12-q14 in humans. 163 19


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