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

We have studied a murine tumor previously classified as a poorly differentiated chondrosarcoma. Although the cells in this tumor are surrounded by large quantities of extracellular matrix material, the matrix fails to react with stains specific for the sulfated glycosaminoglycans present in normal cartilage. Here we show at the ultrastructural level that the tumor matrix is a homogeneous, nonfibrillar material, resembling basement membrane. Neither the proteoglycan matrix granules nor collagen fibrils characteristic of cartilage are present in the tumor matrix. Amino acid analyses of whole tumor tissue, enzyme-solubilized tumor components, and the protein extracted from lathyritic tumors confirmed that the tumor matrix is a basement membrane collagen. The collagenous protein extracted from the tumor by nonenzymatic means contains three unique polypeptides larger than the alpha-chain components of the other types of collagen. These studies indicate that the tumor is not a type of chondrosarcoma but a basement membrane producing tumor.
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PMID:A murine tumor producing a matrix of basement membrane. 83 Jul 88

Endocrine regulation is altered with age. Changes in hormone secretory rates, patterns of secretion, and responses to physiologic and pharmacologic stimuli have been demonstrated. Target tissue sensitivity to hormones appears to be age related and to involve hormone receptor mechanisms, enzymatic responses, and carrier proteins. The aging process reflects changes in cellular structure and metabolism that decrease the function and efficiency of tissues. Structural changes occur with age and are characterized by a loss of elastic tissue, accumulation of highly crosslinked collagen, reduction in ground substance, and an increase in a cellular fluorescent pigment called lipofuscin. These changes decrease the pliability of tissues and alter membrane permeability. Modifications in protein synthesis and enzymatic systems may predispose the aged to autoimmune and neoplastic disease. Endocrine diseases are common in the aged and often may be atypical in their presentation. Cancer is common in the elderly and may be associated with endocrine manifestations because the tumor is producing hormones. Physicians must be aware of these syndromes so that a correct diagnosis can be established, treatment instituted, and the quality of life improved. Laboratory test results in the aged must be carefully interpreted because most aged patients are taking medications that interfere with endocrine tests and also the normal range for the elderly has not been clearly established. Abnormal laboratory diagnostic tests are common in the aged and do not always imply endocrine disease. No hormone can reverse the natural process of aging; however, hormones do regulate all metabolic functions and the neuroendocrine system plays a key role in all phases of growth, maturation, and aging.
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PMID:Physiology of aging: metabolic changes during the climacteric and menopausal periods. 83 75

An unusual malignant fibrous tumor of the testicular tunic in a 35-year-old Japanese man is presented. It apparently arose from the visceral layer of the tunica vaginalis where focal mesothelial hyperplasia was seen. Microscopically the tumor consisted of interlacing bundles of spindle cells and numerous polygonal cells with variable amounts of collagen fibers. The electron microscopic study demonstrated the former cell type closely resembling the fibroblast and the latter to be more epithelial having very plump cytoplasm with fairly well developed desmosomes. The tumor was diagnosed as malignant fibrous mesothelioma upon histopathologic and ultrastructural comparison with the similar tumors in the pleura and peritoneum. Because of the scarcity of the diagnosis in the region it is suggested that fibrous paratesticular tumors are critically reviewed.
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PMID:Malignant fibrous mesothelioma of the tunica vaginalis: a histologic and ultrastructural study. 87 Jan 66

Transmission electron microscopic studies have been carried out on psammoma bodies in two benign and seven malignant papillary serous neoplasms of the ovary. Ultrastructurally, psammoma bodies are composed of microcrystals in all respects similar to calcium-phosphate apatite crystals of bone. The formation of psammoma bodies is initiated intracellularly, in both the neoplastic epithelial cells and stromal histiocytes. The initial seeding site of apatite crystals is served by lipid-rich intracellular vesicles. These structures are produced in association with autophagocytosis in the neoplastic epithelial cells and heterophagocytosis of extracellular lipidic material in the stromal histiocytes. Extracellular lipids presumably derive from dehiscent tumor tissue. The close relationship between larger intraepithelial calcific bodies and microfilaments suggests that the latter provide supportive matrix for further intracellular calcification. Large extracellular psammoma bodies result from fused calcific bodies which have been extruded from calcified cells. Mineralization of extracellular collagen fibers is not observed. The results provide supportive evidence to the concept that psammoma bodies in ovarian papillary serous neoplasms and probably in other neoplastic and non-neoplastic conditions are a consequence of dystrophic calcification associated with cellular degeneration.
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PMID:Ultrastructural studies on the morphogenesis of psammoma bodies in ovarian serous neoplasia. 87 45

We are using three correlated approaches in tissue culture to develop procedures for distinguishing between histologically similar tumors and to develop distinctions that we hope can be correlated with a favorable outcome or with recurrence of more serious disease. Our procedures involve study of the growth of resected tumor tissue in a three-dimensional matrix of collagen-coated cellulose sponge. Using bladder cancer cell lines we are also studying the patterns of cytotypic zonation that appear in response to prolonged exposure to continuous gradients of oxygen tension and of temperature. Finally, we are using vitamin A and modifiers of cyclic adenosine 3':5'-monophosphate as molecular probes to alter the morphological expression of tumors in matrix and in gradient cultures. We have studied over 80 specimens of clinical cancer in matrix culture. Tumors of similar histopathology grow with distinctly different architecture in the matrix of collagen-coated sponge. We must now determine whether these patterns in vitro can be correlated with the course of individual patients.
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PMID:Development of tissue culture procedures for predicting the individual risk of recurrence in bladder cancer. 87 14

Two unusual cases of meningioma with extensive vacuolization have been studied by light and electron microscopy. There were two kinds of vacuoles in the tumor cells which had the characteristic ultrastructure of meningioma as well. The smaller intracytoplasmic vacuoles were lipid droplets, while the larger, more prominent vacuoles were found to be extracellular spaces probably containing plasmatic fluid. The tumor cells were very much stellate with extremely thin and long cytoplasmic processes having desmosome junctions and forming cavernous intercellular spaces, some of which contained collagen fibers and fibrils. Although the xanthomatous change has been well known, the latter features provide a resonable interpretation for the histology of the present tumors and fat-negative vacuoles in the ordinary meningiomas. The picture may be recapitulation of the subarachnoid structure. Furthermore, recognition of this type of meningioma is practically important especially in frozen section diagnosis not to misinterpret the tumor as liposarcoma, chordoma or metastatic adenocarcinoma.
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PMID:Vacuolated meningioma. A light and electron microscopic study. 91 Jun 29

The morphological criteria for the subclassification of Hodgkin's disease were studied in order to obtain a better appreciation of their diagnostic value. We could not separate a specific criterion which would alone permit the diagnosis of a subgroup of Hodgkin's disease. However, the combination of different morphological features including form and frequency of the diagnostic Reed-Sternberg-cells improves the reproducibility of subgrouping Hodgkin's disease. According to their diagnostic significance we consider important: for the LD diffuse infiltration of the lymphnode with few Reed-Sternberg-cells and discret inflammatory reaction; for the MC heavy inflammatory reaction, occasionally with necrosis, numerous diagnostic Reed-Sternberg-cells, occasionally focal involvement in the lymphnode and appearence of birefringent collagen fibers; for the NS the lacunar cells and nodular arrangement of birefringent collagen fibers; for the LP the pleomorphism of the Reed-Sternberg-cells, collagen fibers without birefringency. Based on morphological ressemblance of the nuclei we assume that the tumor cells represent malignant lymphocytes; we consider therefore Hodgkin's disease as a lymphocytic lymphoma.
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PMID:[Morphology of histological subgroups of Hodgkin's disease (author's transl)]. 91 42

Two dogs each had a fibrous tumor of the central nervous system. One tumor involved the spinal cord and ventral nerve root, and the other involved the midbrain and posterior brain stem. Both tumors had spindle-shaped cells arranged in rhythmic patterns. There was perivascular tumor cell infiltration in the adjacent parenchyma. The tumor cells strongly resembled fibroblasts and seemed to produce collagen. Because both tumors were near nerve roots and because their histological appearances were characteristic of nerve sheath tumors they were classified as central neurofibromas.
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PMID:Central neurofibromas in two dogs. 91 37

Ultrastructural studies disclosed that the plaque-like endocardial thickenings in three patients with the carcinoid syndrome were composed of smooth muscle cells embedded in a stroma that was rich in acid mucopolysaccharides, collagen, and microfibrils, but devoid of elastic fibers. The smooth muscle cells contained variable numbers of myofilaments and cisterns of rough surfaced endoplasmic reticulum, and their basement membranes were greatly thickened, reduplicated, and arranged in layers. The endocardial plaques appeared histologically and ultrastructurally similar regardless of their location in the heart. The smooth muscle cells in these plaques appear to have been derived from primitive mesenchymal cells, which normally are present in the subendocardial endothelial space. These observations are interpreted as indicating that the plaques develop as a result of healing of a superficial endocardial injury, which may be initiated by release of bradykinin from hepatic metastases of a carcinoid tumor.
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PMID:The carcinoid endocardial plaque; an ultrastructural study. 93 37

A "fibroleiomyoma" of the lung obtained from a 40-year-old man as a surgical specimen was studied with both the light and the electron microscope. The unusual collagen in this tumor displayed a filamentous helical structure. The filaments measured 50 Angstroms across. Most of the fibrils did not show periodicity. Some, however, showed periodicity of about 700 A. Those with periodicity were smaller in diameter than the fibrils without periodicity. These observations suggest a helical structure of native collagen and may also represent weak cross-linking of tropocollagen in this tumor. This is the first report of collagen showing a helical filamentous structure from human material.
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PMID:Helical structure of human native collagen. 94 52


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