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

The question was examined as to whether immunosuppression in a rat model system would affect the carcinogenic processes leading to tumors in the liver and the large bowel. The protocols were designed to detect an increased incidence or a shorter latent period stemming from a change in immune status. Groups of rats were given injections prior to initiation of the carcinogen regimen and continuously thereafter with a purified gamma fraction of antilymphocytic serum (ALG). Appropriate controls received the gamma fraction of normal rabbit serum or 0.9% NaCl solution. Permanence of skin allografts showed that ALG was an effective immunosuppressive treatment. For liver cancer induction, rats were fed 120 ppm N-hydroxy-N-2-fluorenylacetamide in the diet for 16 weeks, then were continued on control diet. The animals given ALG developed liver tumors at a rate similar to that of controls. For cancer of the large bowel, rats received a single s.c. dose of 7.5 mg azoxymethane per kg per week for 16 weeks and were then held on control diet. With an identical ALG treatment, there were fewer intestinal tumors in the early part of the treatment, because of the important early development of liver angiosarcoma, not seen in control rats given injections of 0.9% NaCl solution. At a later time, the incidence of intestinal cancer was similar in rats on ALG or on 0.9% NaCl solution. Thus, immunosuppression had little effect on the rate of liver tumor formation with a liver carcinogen. Also, ALG led to the precocious development of liver angiosarcomas, but failed to affect intestinal cancer induction in animals given azoxymethane.
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PMID:Immunosuppression in primary liver and colon tumor induction with N-hydroxy-N-2-fluorenylacetamide and azoxymethane. 117 24

Aflatoxin B1 was fed at 2 ppm in the diet to a group of pregnant F344 rats from the time of conception; it was then fed to their offspring until death. This diet was also given to another group of rats 6-7 weeks old for comparison. The survival time of male rats was significantly shorter than that of the female rats of both groups. However, the survival times of rats of the same sex in both groups did not differ significantly. The major causes of death were hepatic neoplasms with matastases, although some early deaths occurred before neoplasms developed. Most deaths were from a malignant hemorrhagic liver tumor, histologically diagnosed as a hemangiosarcoma, which caused rupture and hemorrhage into the peritoneal cavity or metastases to the lungs. These hemangiosarcomas were readily transplantable and did not produce alpha-fetoprotein. Ultrastructurally, they were composed of poorly differentiated cells resembling endothelial cells. Nodules of hyperplasia induced by aflatoxin B1 sometimes grew large (greater than 1.5 cm), and 2 were transplanted. Approximately 20% of the rats had colon tumors; a few rats had tumors of the kidney, oral cavity, and hematopoietic system.
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PMID:Effect of lifetime exposure to aflatoxin b1 in rats. 117 88

Primary hepatic infantile hemangioendothelioma is a rare tumor, characterized by its appearance in early infancy as well as by the frequent association with various malformations and with similar angiomatous tumors of other tissues and organs. It may be single or multinodular and it is often complicated by severe peritoneal hemorrhage. Tow histologic types of this tumor are known: tipe 1 is sharply circumscribed and is considered similar to so called capillary hypertrophic hemangioma, while type 2, by showing aggressive, infiltrative and anaplastic features, is rather close to angiosarcoma. Clinical and pathological data concerning two cases of type 2 primary hepatic infantile hemangioendothelioma are reported. On the basis of experimental results and epidemiological data on hepatic angiosarcoma of adults, a possible etiopathogenetic relationship with maternal exposure during pregnancy to dangerous environmental factors is postulated.
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PMID:[Primary hepatic infantile hemangioendothelioma (author's transl)]. 122 98

In a search for etiologic leads to blood-vessel neoplasms, we examined 111 death certificates of U.S. children who died from 1960 to 1968 of angiosarcoma, hemangioendothelioma, and hemangiopericytoma and 127 medical records of similar cases from 12 institutes. The available data provided no leads to environmental agents (vinyl chloride, thorotrast, arsenic) that can produce vascular liver tumors in adults, but one infant, who died from a hepatic tumor, lived within a mile of an industrial source of polyvinyl chloride. About half of the children with hepatic hemangioendotheliomas had associated skin hemangiomas, which may aid in the differential diagnosis of liver tumors in infancy. Hepatic hemangioendotheliomas also predominated in girls, a possible clue to the origin of the tumor. A familial influence was suggested by one sibling aggregation of cutaneous hemangioendotheliomas.
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PMID:Blood-vessel neoplasms in children: epidemiologic aspects. 124 10

Eighteen cases of anaplastic meningioma were studied by LM, EM and immunohistochemistry for vimentin, EMA, keratin, GFAP and S-100. Microscopically, there were four histologic types, i.e. fibrosarcoma-like, angiosarcoma-like, polymorphic giant cell sarcoma-like and angiopapillary structure. By EM, four kinds of cells: undifferentiated cell, intermediate transitional cell, spindle-shaped cell, and giant cell, were found and variant transitions from undifferentiated or poorly, differentiated to meningioma cells were observed. Their ultrastructures and immunohistochemical features are similar to those of malignant mesothelioma. Since these two kinds of neoplasm showed both mesenchymal and epithelial cells in the features, the authors consider that their histogenesis may also be similar.
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PMID:[The ultrastructural and immunohistochemical observations of anaplastic meningioma]. 128 91

A 20-year-old woman with a primary angiosarcoma of the right atrium is reported. The patient had a cardiorespiratory arrest due to cardiac tamponade with bloody pericardial effusion. Magnetic resonance imaging (MRI) revealed a tumor, which was corroborated by selective coronary angiography. Open-heart surgery was performed. The tumor relapsed however, and she died four months after operation. The tumor was undetectable by echocardiography, but MRI demonstrated a heterogeneous mass with focal areas of high- and low-signal intensity in the right atrium, suggesting that MRI may allow characterization of cardiac tumors.
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PMID:Primary angiosarcoma of the right atrium detected by magnetic resonance imaging. 129 26

Deposition of basement membrane extracellular matrix is influenced by adjacent tumor cells, and in some cases, the pattern of type IV collagen deposit is characteristic in malignant tumors. In this report, we analyzed the difference in type IV collagen deposition patterns between benign and malignant phyllodes tumors (PTs) of the breast. Of the 15 cases of PTs, 8 cases were benign PTs and 7 cases were malignant PTs. Three cases of other primary sarcomas of the breast (stromal sarcoma, angiosarcoma and osteosarcoma) and 2 cases of fibroadenomas were studied for comparison. The malignant PTs were distinguished from benign ones by increased mitotic figures, cellular atypism, and a higher proliferation index of stromal cells. Immunohistochemical staining against type IV collagen in malignant PTs revealed extensive to moderate deposition of type IV collagen around the small blood vessels in duplicate or multilayering pattern, while benign PTs showed minimal deposition in a single linear pattern. All of the three cases of other sarcomas revealed multilayering or meshwork pattern of type IV collagen around the blood vessels. The deposition of type IV collagen around the blood vessels may reflect the malignant behavior of the stromal tumors of the breast.
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PMID:Differential pattern of perivascular type IV collagen deposits in phyllodes tumors of the breast. 129 40

Between April 1986 and August 1990, 151 liver transplantations were performed at our institution, 16 (11%) of them in 14 patients with primary hepatic tumors. There were 12 hepatocellular carcinomas, 1 angiosarcoma, and 1 Klatskin tumor. None of the tumors was resectable, and there was no preoperative evidence of extrahepatic tumoral extension. Exploratory laparotomy was performed prior to transplantation in three patients and selective embolization of the tumor in six patients. There was no difference in the intraoperative requirements for blood or plasma in the patients with hepatic tumors when compared with other transplant recipients (28.6 +/- 23.6 units packed red blood cells [PRBC] versus 20.1 +/- 17.8 units PRBC, and 17.9 +/- 12.2 units plasma versus 17.1 +/- 10.5 units plasma, respectively). Extracorporeal venovenous bypass was used in all but one patient. There was no significant differences in the incidence of acute rejection or in the length of hospitalization in these patients when compared with other transplant recipients. All patients received triple immunosuppressive therapy (corticosteroids, azathioprine, and cyclosporin A). Intraoperative mortality was zero. At a mean of 13.3 months' follow-up (range: 1 to 47 months), 2 of 14 patients had died of sepsis and 1 of terminal cirrhosis (autopsies revealed no evidence of tumor recurrence); 3 patients (21%) had recurrences of the tumor (1 in the central nervous system and liver, and the other 2 in the lung). One of the three patients with a recurrent tumor is still alive after 16 months. The remaining nine patients (64%) are still alive.
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PMID:Liver transplantation in malignant primary hepatic neoplasms. 131 58

A case of low-grade angiosarcoma arising in the skin of a breast previously irradiated for breast carcinoma is reported. Initially, an asymptomatic breast mass was detected. Excisional biopsy and axillary lymph node dissection revealed a 1.5-cm infiltrating ductal carcinoma with 21 negative lymph nodes. The neoplasm was staged as T1, N0, M0. The patient was entered in a research protocol and was treated with high-dose external beam (4,860 rad) and iridium implant (1,860 rad) irradiation. Seven years later the patient developed low-grade angiosarcoma of the breast skin. The lesion recurred following excision and eventually was treated by simple mastectomy. The patient never had evidence of lymphedema. Cutaneous angiosarcomas occurring as a complication of lumpectomy and radiation therapy for breast carcinoma are rare. In some reported cases the patients have had lymphedema, a known factor predisposing to angiosarcoma. Furthermore, almost all cases previously reported have been high grade. This case suggests that radiation therapy for breast carcinoma may also be complicated by low-grade angiosarcoma.
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PMID:Low-grade angiosarcoma of the skin of the breast: a complication of lumpectomy and radiation therapy for breast carcinoma. 131 46

A 19-years-old female with a primary right atrial angiosarcoma partially obstructing the tricuspid valve, developed severe hypoxemia due to right-to-left shunting through a patient foramen ovale. This is the first report of such clinical situation with this type of tumor. A complete resection of the tumor was attempted, and the right atrium had to be rebuilt with a bovine pericardium patch. Post-operative cranial, thoracic and abdominal CT scans and bone scintigraphy did not show metastatic spread. Chest radiation therapy was started on the third postoperative week. Chemotherapy was not used. The patient died five months after surgery due to disseminated metastatic disease but no evidence of the tumor was found in the necroscopic study of the heart.
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PMID:[Primary angiosarcoma of the right atrium with a patent foramen ovale and severe hypoxemia]. 134 70


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