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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extracellular cross-striated banded structures have been found in the connective tissues of a variety of organs. Rarely have they been found in conditions such as: hyperplastic parathyroid, follicular adenoma of the thyroid, metastatic hemangiopericytoma in the lung, sarcoidosis of lymph node, and two biopsies of nerve as reported here. The shape and size of the structure varies, as well as its periodicity, which is usually in the range of 1000 to 15000 A. An unusual exception to this general rule is the banded structure in the follicular adenoma of the thyroid where the periodicity is 270 A. These structures are quite different from native collagen or experimentally reconstituted long-space collagen, both by staining reaction with phosphotungstic acid or uranyl acetate and lead nitrate, and in their ultrastructural morphology.
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PMID:Extracellular cross-striated banded structures in human connective tissue. 5 3

We report the pathological changes in liver biopsies from 10 patients (four female transexuals and six impotent males) after treatment with 150 mg methyltestosterone daily for periods of up to 3 years, and in a hemihepatectomy specimen from a female transexual who developed a liver adenoma after 37 months of this treatment. Hepatocyte hyperplasia and mild focal sinusoidal dilatation was found in most cases. In some cases there were microcysts and dissociation of hepatocytes. In nine patients there was accumulation of hepatocytes between the endothelium and the supporting collagen of hepatic veins which often resulted in either partial occlusion of their lumina or disruption of their walls. These vascular changes do not appear to have been reported before. It is postulated that a single pathological process-hyperplasia, perhaps related to the anabolic effect of methyltestosterone--could be partly responsible both for the formation of cysts through mechanical obstruction of hepatic veins and for the formation of nodules and tumours.
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PMID:Hyperplasia and prolapse of hepatocytes into hepatic veins during longterm methyltestosterone therapy: possible relationships of these changes to the developement of peliosis hepatis and liver tumours. 61 37

Capsule invasion observed in instances of adenomas of the thyroid was studied in correlation with the clinical course of the patients. The invasion, as defined in the cut-off and turn-out of the collagen fibers in the capsule, occurred in eight of 611 adenomas. The clinical course of the eight patients revealed no recurrence of an adenoma, even though there was no antitumor drug therapy. On the other hand, recurrences of adenomas were found in five of the 603 patients with noninvasive adenoma, of the 603 patients with noninvasive adenoma. Capsule invasion, therefore, is not a cause for the recurrence of an adenoma. The recurrence may result from the leaving of microadenoma in the thyroid when the first operation took place. Capsule invasion cannot be considered as a histologic sign of malignant tumor of the thyroid.
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PMID:Surgical significance of capsule invasion of adenoma of the thyroid. 85 Aug 54

Morphological analysis of the sclerotic changes in peripheral lung carcinoma (PLC) and nephrosclerosis in renal-cell carcinoma (RCC) established a promoting role of sclerosis in carcinoma development. The pneumosclerosis role as a background process in the PLC development is proved by the following facts: high proportion (83%) of the carcinoma in the scar among PLC; identity of the scar collagen composition in PLC and that in metatuberculosis and metapneumonic pneumosclerosis foci; detection of metatuberculosis foci in 75% of PLC; the presence of the precancerous changes in the epithelium entrapped in the pneumosclerotic foci, not only with signs of morphological atypia, but with the disturbance of nuclear DNA and cellular oncogene expression as well. The association of RCC with nephrosclerosis is shown by a high proportion (82.7%) of the RCC development against the background of nephrosclerosis; the dependence of the so-called cortical adenoma development on the degree of nephrosclerosis; epithelial proliferation in the nephrosclerotic foci with the appearance of undifferentiated cells with the altered DNA content and the expression of cytokeratins and vimentine. Carcinoma morphogenesis against the background of sclerosis may be described as follows: development of sclerosis (focal and/or diffuse), the appearance of the focal epithelial hyperplasia in the scar, dysplasia or adenoma and finally carcinoma.
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PMID:[Sclerosis and carcinogenesis]. 128 96

Proliferative Leydig cell (LC) alterations (hyperplasia, adenoma) of laboratory rats often pose diagnostic problems because the progression from normal to hyperplasia to neoplasia is continuous. The LC compartments of 130 Wistar rats (kfm: WIST strain) of approximately 2 years of age were examined. Ten typical cases conventionally classified as being normal or as showing diffuse or focal hyperplasia or small or large adenomata were investigated in more detail. In large adenomata, areas with large and small LC nuclei were identified. Immunohistochemical characterization, EM examination, as well as stereologic and planimetric investigations were performed. Hyperplastic and neoplastic LC essentially retained their normal appearance and immunohistochemical characteristics, but were found to contain more lipid droplets, fibroblast-like cells and patches of collagen than normal LC at the EM level. LC proliferation was accompanied by significant LC hypertrophy. LC nuclei of hyperplastic LC compartments were slightly larger while those of LC adenoma were markedly larger than nuclei of normal LC. The values for circle-related and ellipticity factors indicated that the nuclei of normal and hyperplastic LC were more markedly oval than nuclei of neoplastic LC. Concavity factor and bending energy measurements revealed that the small and oval nuclei of normal and hyperplastic LC had significantly more and deeper indentations than the larger and somewhat rounder nuclei of neoplastic LC. It is concluded that LC proliferations conventionally diagnosed as hyperplasia or adenoma on the basis of their size were composed of cytologically different LC populations.
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PMID:Morphological, immunohistochemical, stereological and nuclear shape characteristics of proliferative Leydig cell alterations in rats. 140 4

A 23-year-old man had a lesion in the right inferior iris which appeared to have enlarged since it was first seen when the patient was aged 5 years. The lesion was excised by a partial iridocyclectomy. Histopathologically the neoplasm was composed of both pigmented and non-pigmented cells. Pseudoacini, containing acid mucopolysaccharides, were present throughout the tumour matrix. Electron microscopically the non-pigmented cells were found to possess a convoluted plasmalemma, abundant rough endoplasmic reticulum, and numerous desmosomes and gap junctions. The pigmented cells contained large, round, mature melanosomes, occasional premelanosomes, and desmosomes, which resembled the posterior pigment epithelium of the iris. The intercellular matrix contained fine collagen fibrils resembling vitreous. We believe that this neoplasm represents a congenital adenoma of the ciliary body and iris.
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PMID:Congenital adenoma of the iris and ciliary body: light and electron microscopic observations. 142 64

In order to determine the participation of basement membrane molecules in formation of its characteristic stroma, 30 cases of salivary gland pleomorphic adenoma were examined by immunohistochemical staining for type IV collagen, laminin, heparan sulfate proteoglycan, and entactin. The stroma was histopathologically classified into four types: hyaline, fibrous, myxoid, and chondroid. Immunohistochemically, type IV collagen and laminin were more intensively localized in hyaline, fibrous and chondroid types of stroma, whereas heparan sulfate proteoglycan was more prominent in myxoid areas. The results suggest that the stroma contains these basement membrane components, which are possibly biosynthesized by epithelial tumor cells, and that histological variety of the stroma depends on proportion of local contents of each basement membrane molecule.
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PMID:Immunolocalization of basement membrane molecules in the stroma of salivary gland pleomorphic adenoma. 169 44

In order to clarify the neoplastic-mesenchymal cell interaction, tumor structures were histologically classified into duct, solid and scattered types, and stromal changes were observed in each type with histochemical techniques. The quantitative and qualitative differences of the stromal components as proteoglycan and collagen were histochemically differed in these morphological features. Ca++ ATPase was ultrastructurally localized on the plasma membrane of myoepithelial cell in salivary glands. The activity of Ca++ ATPase changes in tumor cell differentiation of pleomorphic adenoma and adenoid cystic carcinoma. These results suggest that the stromal components and Ca++ ATPase play an important role on the tumor cell proliferation and differentiation in these tumors.
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PMID:[The role of stromal components and Ca++ ATPase in pleomorphic adenoma and adenoid cystic carcinoma]. 171 15

The present work was designed to compare in vitro cell growth kinetics with in vivo growth under conditions as similar as possible using labeling with [3H]thymidine. To this purpose, FRTL-5 cells were cultured as monolayers and as three-dimensional spheroids embedded in collagen gels and transplanted simultaneously into nude mice treated with perchlorate and a low iodine diet. The growth of the transplants was compared to that of the thyroids in host mice. In the intact thyroid, the fraction of [3H]thymidine-labeled follicular cells (FLC; 24-h labeling) increased sluggishly to a maximum of 10% after 3 weeks of goitrogen exposure, with a subsequent autoregulatory decrease to 3% at 7 weeks. A 4-fold higher FLC was found in six adenomas, indicating focal failure of growth-restraining mechanisms. In nonconfluent monolayer cultures the FLC was as high as 90%, even within large individual clusters where cells are in tight mutual contact. Solid, highly cellular grafts growing from transplanted monodispersed cells showed an average FLC of 20%, which is 5 times higher than the FLC in the identically stimulated mouse thyroid. In collagen-embedded cells, forming three-dimensional spheroids, the mean FLC decreased from 70% at 1 week in vitro (40% in vivo) to 20% at 3 weeks both in vitro and in vivo, suggesting effective auto-regulation of excessive growth in both conditions. However, these FLC were again much higher than the 3% FLC in simultaneously assessed host thyroids. The difference remained throughout the 45-day period studied. We conclude that FRTL-5 cells growing as monolayers and as three-dimensional spheroids in vitro or after xenotransplantation in vivo invariably show much higher proliferation rates under comparable environmental conditions than the normal follicular epithelium in the thyroids of host mice. The one exception is the confluent monolayer with near-zero growth, while densely packed three-dimensional transplants still grow intensively. Although growth-retarding cell to cell interactions are also clearly operative in growing FRTL-5 cells, they are less effective than those dampening the replication rate of the thyrocytes within the monolayer hull of normal follicles. A local failure of these mechanisms, allowing growth rates comparable to those of grafted FRTL-5 cells results in adenoma formation in normal thyroids. These observations call for caution in the transfer of in vitro growth studies with FRTL-5 cells to in vivo conditions prevailing in the normal thyroid.
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PMID:Comparison of FRTL-5 cell growth in vitro with that of xenotransplanted cells and the thyroid of the recipient mouse. 184 98

An account is given in this paper of functional black adenoma of the adrenal cortex. Autonomous hormone secretion of the tumour was confirmed by pre- and postoperative biochemical tests. Electron microscopy revealed two types of pigment granules. Mitochondria showed severe impairment. A relationship was assumed to exist between mitochondrial alterations and accumulation of lipoid-containing pigment because of the important role of mitochondria in lipid metabolism. Abnormal collagen fibrils were found in the cytoplasm of tumour cells. Comparison of the presented black adenoma with two nonpigmented adrenal adenomas showed the ultrastructure of black-adenoma cells to be similar to the compact cells of "yellow" cortical adenomas. However, the latter contained normal mitochondria and one type of pigment granules. Adrenal black adenoma thus can be regarded as a pathological entity.
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PMID:Functioning "black adenoma" of the adrenal gland with emphasis on ultrastructural studies. 191 30


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