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

A pituitary adenoma was removed transsphenoidally from a 20-yr-old woman with secondary amenorrhea, galactorrhea, and hyperprolactinemia. Light and electronic microscopy, immunocytology characterized a prolactin cell tumor. The patient also underwent three surgical explorations for hyperparathyroidism. Only after selective catheterization of thyroid veins with radioimmunoassay for parathormone, an intrathyroidal parathyroid adenoma was found. No other case of proven prolactin adenoma in Wermer's syndrome has been reported.
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PMID:[Endocrine polyadenomatosis associated with prolactin pituitary adenoma and an intrathyroidal parathyroid adenoma]. 1 58

Light and electron microscopical examination of a pituitary adenoma showed that the tumor was composed of prolactin cells that produced amyloid-like material. The findings have been interpreted in favor of the role of rough endoplasmic reticulum in amyloid fibril formation within the adenoma cells. Histochemical and fine structural data indicate that the material produced by this tumor resembles apudamyloid rather than immunoamyloid.
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PMID:Pituitary adenoma producing amyloid-like substance. 5 61

Seventy tests of stimulation with hypothalamic thyreotrophic hormone liberation factor, and 35 bromocriptine inhibition tests were carried out on a routine basis in patients with latent or frank hyperprolactinaemia. Pathological hyperprolactinaemia does not have a single clinical pattern: frank, it takes the form either of an exteriorised pituitary adenoma (14 cases), or of an amenorrhoea-galactorrhoea syndrome with or without micro-adenoma (12 cases); latent, it takes the form either of isolated amenorrhoea (17 cases) or of dysovulatory sterility (16 cases). Amongst the dynamic tests available, it is worthwhile to make a choice, and in the case of frank hyperprolactinaemia, the authors propose use of the bromocriptine inhibition test in the first instance. The TRH test is reserved for verification of the results of neurosurgery. As far as latent hyperprolactinaemia is concerned, it may be identify only by the TRH test, with the resultant possibility of specific treatment.
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PMID:[Diagnosis of hyperprolactinaemias: respective value of response to THR and to bromocriptine (author's transl)]. 9 29

The degree of autonomy in prolactin secreting pituitary adenomas and also prolactin secretory reserve in cases with suspected functional galactorrhea syndrome was evaluated with the use of metoclopramide, TRH and L-DOPA. It was found that in patients with pituitary adenoma the basal prolactin (PRL) level often exceeded 150 micrograms/l and the response to stimulation with TRH and/or metoclopramide was markedly diminished or even nonexistent, while the response to L-DOPA was usually retained. In patients with galactorrhoea and/or amenorrhoea, with normal skull X-ray the basal PRL level was either normal or moderately raised but the response to stimulation was various; mostly it was excessive, it was sometimes normal, but in some other cases it was markedly diminished as in patients with adenoma. In the author's opinion the so-called "functional disorder" of prolactin secretion is mainly hyperresponsiveness to stimulation, whereas the basal PRL level in those cases is usually normal or only intermittently raised. In the cases with a moderate hyperprolactinaemia, especially if it appears to be constant, and the response to stimulation is diminished or none at all, we suspect a pituitary microadenoma. Finally, there are rare cases of galactorrhoea with normal basal PRL and normal response to stimulation, in which the sensitivity of the mammary PRL receptor is probably increased. We suggest therefore that the above mentioned PRL stimulation tests may help in distinguishing between tumoural and functional hyperprolactinaemia.
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PMID:The effect of metoclopramide, TRH and L-dopa on prolactin secretion in pituitary adenoma and in "functional" galactorrhoea syndrome. 11 17

Twenty women with hyperprolactinaemia secondary to a pituitary adenoma were studied before and after selective transsphenoidal removal of the tumour. Pre-operatively, thyrotrophin-releasing hormone (TRH) (200 micrograms iv) and metoclopramide (MCP) (10 mg po) did not produce a positive PRL response in the tumour patients. By contrast, 14 post-partum lactating women, who were used as controls, exhibited a positive response to MCP administration. Methergoline (4 mg po) was shown to decrease serum PRL levels in 8 normal subjects, in 6 puerperal women, and 9 of 10 tumour patients. Bromoergocriptine (CB-154, 2.5 mg po) decreased serum PRL levels in 10 tumour patients. Following transsphenoidal removal of the adenoma serum PRL levels were reduced in all patients, and returned to normal in 14 patients. Prognostics for completely normalizing PRL secretion after transsphenoidal surgery is bettery when initial serum PRL levels are below 200 ng/ml. After surgery all hyperprolactinaemic patients failed to show a positive PRL response to TRH and MCP. Nine normoprolactinaemic patients had a positive response to both stimuli while 3 patients failed to show a positive response immediately following surgery. Long-term studies, however, showed that a positive PRL response was obtained in all patients tested 8-14 months after treatment. A positive PRL response to methergoline and bromocriptine was observed post-operatively in the patients tested regardless of their basal PRL level. Data from this study indicate that surgically proven PRL-secreting adenomas are invariably associated with negative PRL responses to TRH and MCP. The normalization of the prolactin regulation after surgery points toward the intrapituitary localization of the lesion associated with PRL-secreting adenomas.
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PMID:Prolactin-secreting pituitary adenomas: prolactin dynamics before and after transsphenoidal surgery. 11 18

To determine the site of action of TRH and 2-brom-alpha-ergocriptine (CB154) on pituitary hormone release in acromegalic patients, the effect of these substances on GH and PRL secretion was examined in perfused pituitary adenoma tissues obtained at surgery from subjects with acromegaly. Relatively stable baseline secretion levels of GH and PRL were followed by an abrupt and marked discharge of the hormones after TRH infusion in all of the experiments. The pattern of GH response was essentially the same as that of PRL. Moreover, a dose-response relationship was obtained between the TRH concentrations infused and the magnitude of GH and PRL responses. The infusion of CB154, on the other hand, inhibited both GH and PRL secretion in three experiments performed on different adenoma tissues. This effect of CB154 was prompt and lasted for a long period even after the infusion was discontinued. When TRH was perfused concomitantly with CB154, the stimulatory effect of TRH on GH release was maintained, while TRH-induced PRL secretion was completely blocked. The results suggest that both TRH and CB154 possess a direct action on pituitary adenoma cells of acromegaly and that aberrant GH responses to TRH and dopaminergic agonists in acromegalic patients may be explained by the altered cellular membrane receptors of the adenoma of these subjects.
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PMID:Effect of thyrotropin-releasing hormone and bromoergocriptine on growth hormone and prolactin secretion in perfused pituitary adenoma tissues of acromegaly. 12 26

A chromophobic pituitary adenoma induced on BD IX-rats has been grafted on animals of the same strain. The transplanted tumour takes in 90-100%; it grows at a slow rate (in 7 months after grafting a weight of 7-20 g is attained). Tumour-bearing animals display gigantism and hypertrophy of adrenals; moreover, in 33% of cases, diabetes is observed. With non-diabetic animals, splenomegaly and marked leukocytosis are observed; immature white and red cells are present in the peripheral blood. Spontaneous regression of the tumour never occurs. After surgical removal, tumour regrowth and the formation of metastases are observed. Diabetes is characterised by pronounced hyperglycaemia, glucosuria, polyphagia and polydipsia. Histochemically, insulin cannot be detected in pancreas. Splenomegaly is never observed in diabetic animals. Transplanted adenoma frequently tends to stop growing. No recurrence is observable after extirpation. Spontaneous regression of the tumour sometimes occurs. Gigantism, hypertrophy of adrenals and diabetes are considered as consequences of growth hormone- and ACTH-secretion of the transplanted adenoma. At present the tumour is running in the 8th passage. It did not change its characteristics over a period of 5 years.
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PMID:Transplantable, STH-producing and diabetogenic pituitary adenoma of the BD IX-strain of rats. 17 13

Pituitary adenomas arise from and consist of adenohypophyseal cells. Based on the tinctorial characteristics of the cell cytoplasm, they were divided previously into chromophobic, acidophilic, and basophilic adenoma types. This classification is only of limited value, since it fails to consider the endocrine function of the adenoma cells and the cell type from which the tumor originates. Advanced morphologic techniques, including electron microscopy and immunocytology, led to a new pituitary adenoma classification reflecting current knowledge and attributing greater significance to clinical features, structure-function relationships, and cytogenesis. The morphologic study of pituitary adenomas is still in a relatively early stage and much more work is required to understand the basic principles of pituitary cytopathology. Thus, the classification used in this review may change as new facts accumulate. We feel justified to say that attempts to correlate structural features of pituitary adenomas with secretory activity and their separation into distinct entities cannot be regarded as examples of curiosity-oriented research. This type of investigation represents not only an intellectually rewarding experience, but is also of practical value and provides important information for the endocrinologists.
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PMID:Pituitary adenomas. 20 13

This report concerns the course of an eosinophil pituitary adenoma in an acromegalic female (16 years of age when first symptoms appeared) over a period of ten years. The case was complicated by craniocerebral trauma and CSF rhinorrhoea. After several operations, dedifferentiation, and invasive growth into the orbit and the petrous bone were observed with walling in of the VIIIth cranial nerve. The possible causes of the dedifferentiation of the adenoma are discussed.
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PMID:Dedifferentiation and invasive growth of an eosinophil pituitary adenoma. 20 57

Radiographs of 146 patients who had a pituitary adenoma removed by the transsphenoidal approach were reviewed. The area and volume of the sella were measured in all the patients. In 73 patients the sella had a normal size and appearance as shown on routine lateral and frontal radiographs. However, thin-section tomograms of the sella in these patients demonstrated findings indicative of an intrasellar mass in all but three instances. The diagnosis of pituitary microadenoma (adenoma less than 1.5 cm in diameter) may, therefore, be missed if only plain skull radiographs are used to assess the sella. No correlation could be shown between the location of the sellar changes seen using thin-section tomography and the histologic type of pituitary adenoma.
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PMID:Radiologic assessment of pituitary microadenomas. 21 Jun 44


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