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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Soft tissue tumors with the characteristics of Ewing sarcoma of bone have thus far only been studied by light microscopy. A pelvic tumor of this type in a 13-year-old girl was examined by electron microscopy. Comparison of its ultrastructural features with those of reported cases of bony Ewing sarcoma reveal much similarity. It is believed that they are probably identical and that the tumor cells are of immature mesenchymal type. However, their site of origin and the direction of their potential differentiation remain obscure.
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PMID:Extraskeletal Ewing sarcoma. An ultrastructural study. 57 77

Twenty previously untreated children with primary Ewing's sarcoma and 8 children with primary tumor and metastatic disease were treated with surgery or radiation therapy (6,000-7,000 rads) for their primary tumor and T-2 chemotherapy. Of the 20 children with primary Ewing's sarcoma treated with T-2 "adjuvant" chemotherapy, 15 had no evidence of recurrent disease for from 31+-82+ months (median 46+ months) from the start of treatment. The actuarial 5-year disease-free survival rate for this group of patients was 75%. Eight patients presenting with metastatic disease had complete responses to T-2 chemotherapy, but 7/8 with metastatic disease eventually had tumor recurrence. Examination of the treatment failures, both those patients relapsing after adjuvant chemotherapy for primary Ewing's sarcoma (5), and those relapsing after having a complete response of metastatic disease (7) to T-2 chemotherapy, revealed that all relapses occurred at the end of the second year of T-2 chemotherapy or after chemotherapy was stopped. In addition, of 23 patients receiving "curative" radiation therapy to their primary tumor, 5 had local recurrence (22%) and 6 (26%) had severe functional debility secondary to combined radiation therapy and T-2 chemotherapy. The conclusions drawn from this experience have led us to consider a new approach to the treatment of Ewing's sarcoma, namely: 1) more aggressive initial or "induction" chemotherapy with subsequent T-2 "maintenance" chemotherapy to eradicate more completely all metastatic microfoci of disease presumed to be present in patients with primary tumor at the time of diagnosis, and ostensively present in patients with metastatic disease; 2) the use of surgery alone or in combination with moderate doses of radiation therapy in those patients in whom we can predict a high frequency of local recurrence (pelvic lesions) or a high percentage of "functional failures" (young children with lower extremity lesions). Preliminary results with this latter approach are encouraging with 11/13 patients with primary Ewing's sarcoma free of disease at 12+-26+ months. A longer follow-up of this more aggressive treatment is needed to determine the superiority of this approach for both increased survival and improved late physical rehabilitation.
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PMID:Curability of Ewing's sarcoma and considerations for future therapeutic trials. 63 76

An autopsy study of 26 cases of Ewing's sarcoma treated with radiation to the primary site plus adjuvant chemotherapy has shown metastatic tumor in 23 cases. Metastases were found typically in lungs, pleura, bones and regional lymph nodes. In three cases no tumor could be found at autopsy, and death was due to complications of treatment. Tumor was found in the irradiated primary site in 13 of the 20 cases in which the primary site was examined at autopsy. Histologically, the tumor at autopsy frequently had increased pleomorphism and increased numbers of bizarre giant cells; however, these changes did not affect the presence of glycogen in tumor cells, thus reaffirming the importance of intracytoplasmic glycogen in the diagnosis of Ewing's sarcoma.
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PMID:Ewing's sarcoma: an autopsy study. 65 96

The association of consumptive coagulopathy and malignancy is thought to be rare in pediatrics. In one patient with Ewing's sarcoma and in two with rhabdomyosarcoma consumptive coagulopathy developed in the presence of either diffuse metastatic disease or an extensive primary tumor. The coagulopathy was a major clinical problem, developing within five days of the onset of chemotherapy. Resolution coincided with the clinical response of the tumor.
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PMID:Consumptive coagulopathy. A complication of therapy of solid tumors in childhood. 68 3

Twenty-one cases of Ewing's sarcoma were analyzed by light- and electron-microscopy and the fine structure compared to that described in previous publications. In the predominant "primary" tumor cells, glycogen was abundant in 53% of cases, infrequent in 33%, and rare in 14%. In three cases, microtubules, in association with glycogen, were demonstrated. The so-called differentiated "secondary" reticular tumor cells were sparsely populated in eight cases. Evidence is presented to suggest that these so-called "secondary" reticular cells are merely "primary" tumor cells in a state of regression. Secondary cells and cells with nuclear identations or convolutions were of no discernible prognostic significance. The histogenesis of Ewing's sarcoma remains an enigma but present findings support a primitive mesenchymal origin.
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PMID:Ewing's sarcoma. A light- and electron-microscopic study of 21 cases. 68 32

The light and the electron microscopic features of an extraskeletal round-cell tumor resembling Ewing's sarcoma are described. Ultrastructural observation revealed features similar to Ewing's sarcoma of bone. Variable agrees of nuclear complexity are described. These soft tissue tumors are probably composed of undifferentiated mesenchymal cells; there is no ultrastructural evidence to indicate the cell of origin.
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PMID:So-called extraskeletal Ewing's sarcoma. Report of a case with ultrastructural analysis. 72 78

Observations on 73 cases of Ewing's tumor confirmed that this neoplasm occurs in twice as many males as females, mostly between the ages of 11 and 20. In contrast with other reported series, 61.6% of lesions in our patients were in the flat bones. Definite diagnosis cannot be based solely on clinical and radiological changes, and no patient suspected of suffering from Ewing's tumor should receive x-ray treatment or any other kind of therapy unless the diagnosis has been proved histologically, by means of open biopsy. Supervoltage radiation therapy combined with chemotherapy produces better results than other kinds of treatment.
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PMID:Ewing's tumor. Review of 73 cases. 81 34

Primary tumor control rates were studied in two groups of patients with Ewing's tumor. They received high doses of radiation combined with a standard chemotherapy regimen incorporating multiple agents. Another 17 had either less chemotherapy or none at all. The data suggest that treatment dose and control are correlated and that intensive chemotherapy contributes to destruction of the primary tumor.
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PMID:Radiotherapy of Ewing's sarcoma. Local control with and without intensive chemotherapy. 82 Oct 98

Radiotherapy of bone tumors can now be performed exclusively by megavolt therapy. Giant cell tumors hsould be resected. If the lesion is not completely resectable, surgery should be followed by the administration of a target dose of 3000 rads in 4-6 weeks. Inoperable giant cell tumors are irradiated to a tumor dose of 5000 rads, inoperable giant cell tumors of grade III receive a dose of 8000 rads as do osteosarcomas. Ewing's sarcoma and reticulum cell sarcoma can be totally destroyed by a tumor dose of 6000 rad with sufficient reliability. Combination with chemotherapy may offer a chance of improvement. Osteosarcoma should be resected. If surgery is too late (early distant metastases), a tumor dose of 8000 to 10000 rads would be able to destroy the tumor cells. Histologic control investigations have proved this.
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PMID:X-ray therapy of primary bone tumors. 82 97


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