37 resultados para MYXOMA


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Heterotranplantability of myxoma of rabbits was formely demonstrated when grafts from subcutaneous tissue in skin were used (MARGARINOS TÔRRES & RITA CARDOSOS, 1949). Better results are reported in this paper when grafts from the spleen of infected rabbits were employed. While grafts from normal spleen are almost completely absorbed in sixteen days, those from infected rabbits give origin to full-grown and vascularised tissue in which typical myxoma cells are predominant elements. Progressive growth of heterotransplantated myxoma cells is another similarity between infectious myxoma and malignant tumors. Formation of clear areas of circular contour (interference of a diffusible substance?) associated to myxomatous degeneration is very conspicuous. Peculiar changes of the ground substance, reticular and collagenous fibers (globular swelling, rosary and bulb formation) apparently related to myxomatous degeneration are described. An unexpected finding was the presence of typical intranuclear inclusion bodies in five among forty-eight grafts examined in the sixth day.

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Aggressive angiomyxoma is a rare, slow-growing soft tissue tumor that usually arises in the pelvis and perineal regions of women in reproductive age, with a marked tendency to local recurrence. Because of its rarity, it is often initially misdiagnosed. Surgical resection is the main treatment modality of aggressive angiomyxoma. We describe a case of a vaginal aggressive angiomyxoma in a 47-year-old woman in which the diagnosis was only made after histological examination. The etiology, presentation, diagnosis and management of this rare tumor are outlined. Angiomyxoma of vulva and vagina refers to a rare disease. Pre-operative diagnosis is difficult due to rarity and absence of diagnostic features, but it should be considered in every mass in genital, perianal and pelvic region in a woman in the reproductive age. Thus, these cases should have complete radiological workup before excision, as pre-diagnosis can change the treatment modality and patient prognosis'.

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The odontogenic myxoma shares cellular and structural aspects with dental papilla, which has been implicated as probable origin of this neoplasm. The aim of the present study was to perform a comparative immunohistochemical analysis for the expression of collagenase-1 (MMP-1) and gelatinases A (MMP-2) and B (MMP-9) in odontogenic myxomas and dental papilla of teeth germs. Twelve cases of odontogenic myxomas and eight specimens of teeth germs were selected. It was taken into consideration the presence or absence of immunoreactivity, the pattern of immunohistochemical distribution of proteases within extracellular matrix, as well as, the number of cells revealing immunostaining for matrix metalloproteinases (MMPs). It was verified a significant difference (p<0,05) in relation to MMP-2 immunoexpression, which was observed only within extracellular matrix of myxomas. Nevertheless, MMP-1 labeling was revealed by most of the cases of odontogenic myxoma, at levels close to those observed in dental papilla. In relation to the pattern of distribution, a significant difference was obtained between specimens (p<0,05), with neoplasms predominantly exhibiting a focal pattern for MMP-1. The quantitative analysis of neoplastic cells labeled for MMPs denoted a significant difference (p<0,05), demonstrating a higher proportion of MMP-1 in comparison to MMPs-2 and -9. It can be concluded that immunohistochemical expression of MMP-1 at levels comparable to those observed in dental papilla and quantitatively superior in relation to MMPs-2 and -9, suggest an implication of this protease on extracellular matrix degradation of odontogenic myxomas. Moreover, the possibility of interactions with receptors involved in cellular adhesion, particularly with integrins, suggests a plausible function on local invasiveness of such neoplasms. Additionally, the presence of a descent immunoexpression gradient for these MMPs on odontogenic myxomas, associated to substrate specificity inherent in each enzyme, suggest the existence of a coordinated mechanism between interstitial collagenase and gelatinases A and B in order to allow an efficient degradation of extracellular matrix and local invasion by neoplastic cells

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Bovine enzootic hematuria is characterized by the development of hemangiomatous lesions from several types of neoplastic processes, from epithelial and mesenchymal origin. In this research the histogenesis of neoplastic lesions found in bladder of bovines with enzootic hematuria from Caparaó microregion in the state of Espírito Santo, Brazil was determined. To accomplish this objective, immunohistochemical analysis was performed with primary antibodies: anti-vimentin, anti-cytokeratin, anti-CD31 and anti-uroplakin. Neoplasms found included urothelial carcinoma, in situ carcinoma, adenocarcinoma, hemangioma, myxoma e hemangiosarcoma. Immunohistochemical staining of cytokeratin in epithelial neoplasms and vimentin in mesenchymal neoplasms was significant (p<0.05). CD31 was positive in all the vessels of all samples, however, the staining was significant (p<0.05) in the tumor endothelial cells of the vascular mesenchymal neoplasms, as in hemangiomas and hemangiosarcomas. Uroplakin III staining was uneven in several neoplastic types and showed no significant difference (p>0.05). Most neoplasms showed an atypical uroplakin staining on urothelium and, in the case of hemangiosarcomas there was no staining of the urothelium at all. The Spearman statistical analysis revealed a positive correlation (r= 0.63, p= 0.05) between CD31 and vimentin and between cytokeratin and uroplakin (rs= -0.61, p= 0.05). It was concluded that biomarkers anti-cytokeratin, anti-vimentin and anti-CD31 are important for the diagnosis of neoplasms epithelial, mesenchymal and vascular mesenchymal, respectively. It is possible to use vimentin and CD31 in association in vascular mesenchymal neoplasms and cytokeratin and uroplakin in epithelial neoplasms. The uroplakin is an effective marker, not only for tumor diagnosis, but also to evaluate the urothelial integrity.

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Introduction. Primary cardiac tumors are uncommon in cardiac surgery. To investigate the clinical presentation, surgical results and long-term follow-up we retrospectively analyzed our experience in the treatment of primary cardiac tumors. Patients and methods. Ninety-one patients with primary cardiac tumors underwent surgery in our department in the last 20 years. Fifthy-one patients were female, the mean age was 62,2 years. Sixty-three had myxomas, 22 had papillary fibroelastoma, 4 had malignant neoformations and 2 had other benign tumors. Results. All myxomas, fibroelastomas and angiomyolipoma were radically removed. Only a palliative treatment was possible in malignant disease. In-hospital mortality was 1.2%. The mean follow-up time was 78.5 months. Three patients had recurrence of myxoma, all patients with malignant disease dead during the follow-up. Discussion. Primary benign cardiac tumors can be treated with low morbidity and mortality. The follow-up demonstrates that radical surgery is curative in case of benign tumors. The prognosis of malignant tumors is still poor. Palliative procedures have small impact on survival in these patients.

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Adoptive immunotherapy and oncolytic virotherapy are two promising strategies for treating primary and metastatic malignant brain tumors. We demonstrate the ability of adoptively transferred tumor-specific T cells to rapidly mediate the clearance of established brain tumors in several mouse models. Similar to the clinical situation, tumor recurrences are frequent and result from immune editing of tumors. T cells can eliminate antigen-expressing tumor cells but are not effective against antigen loss variant (ALV) cancer cells that multiply and repopulate a tumor. We show that the level of tumor antigen present affects the success of adoptive T cell therapy. When high levels of antigen are present, tumor stromal cells such as microglia and macrophages present tumor peptide on their surface. As a result, T cells directly eliminate cancer cells and cross-presenting stromal cells and indirectly eliminate ALV cells. We were able to show the first direct evidence of tumor antigen cross-presentation by CD11b+ stromal cells in the brain using soluble, high-affinity T cell receptor monomers. Strategies that target brain tumor stroma or increase antigen shedding from tumor cells leading to increased crosspresentation by stromal cells may improve the clinical success of T cell adoptive therapies. We evaluated one potential strategy to complement adoptive T cell therapy by characterizing the oncolytic effects of myxoma virus (MYXV) in a syngeneic mouse brain tumor model of metastatic melanoma. MYXV is a rabbit poxvirus with strict species tropism for European rabbits. MYXV can also infect mouse and human cancer cell lines due to signaling defects in innate antiviral mechanisms and hyperphosphorylation of Akt. MYXV kills B16.SIY melanoma cells in vitro, and intratumoral injection of virus leads to robust, selective and transient infection of the tumor. We observed that virus treatment recruits innate immune cells iii to the tumor, induces TNFα and IFNβ production in the brain, and results in limited oncolytic effects in vivo. To overcome this, we evaluated the safety and efficacy of co-administering 2C T cells, MYXV, and neutralizing antibodies against IFNβ. Mice that received the triple combination therapy survived significantly longer with no apparent side effects, but eventually relapsed. Based on these findings, methods to enhance viral replication in the tumor and limit immune clearance of the virus will be pursued. We conclude that myxoma virus should be further explored as a vector for transient delivery of therapeutic genes to a tumor to enhance T cell responses.