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

Ectopic pituitary adenomas without associated intrasellar adenomas are rare and are usually located in the sphenoid sinus. Most have been reported without modern radiological, endocrinological, or electron microscopic (EM) documentation. The case of a 47-year-old man with a third ventricular, ectopic, clinically nonsecretory pituitary adenoma, which was shown to be a gonadotrophic adenoma by immunohistochemical and EM study, is reported. Neurological examination, extensive neurodiagnostic imaging, surgical anatomical observation, and endocrinological evaluation showed no evidence of neoplasia outside the third ventricle.
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PMID:Ectopic pituitary adenoma of the third ventricle. Case report. 229 74

We studied the sequential changes of plasma levels of immunoreactive '7B2' (IR-7B2), a neuroendocrine polypeptide, after a subcutaneous injection of 50 micrograms of synthetic octapeptide somatostatin analogue (SMS 201-995) in seven patients with acromegaly due to GH-producing pituitary adenoma. Compared to the basal levels, mean plasma IR-7B2 and GH levels significantly decreased, until 5 and 10 h respectively after the administration of SMS 201-995. The mean (+/- SEM) nadir levels of plasma IR-7B2 and GH were 68.1 +/- 10.1 and 13.1 +/- 6.9%, respectively, compared to mean plasma levels before treatment (100%). Plasma IR-7B2 as well as GH levels did not change significantly when saline was administered subcutaneously to three acromegalic patients. In addition, plasma IR-7B2 levels did not change significantly after the administration of SMS 201-995 in normal subjects or in patients with primary hypothyroidism in whom SMS 201-995 induced a decrease of plasma TSH levels. These results strongly suggest that SMS 201-995 has an unequivocal suppressive effect on the synthesis and/or the secretion of 7B2 in human somatotroph adenoma cells.
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PMID:Effect of octapeptide somatostatin analogue (SMS 201-995) on plasma 7B2 (a neuroendocrine polypeptide) levels in patients with acromegaly. 233 11

A 66-year-old woman presenting with pituitary insufficiency was operated on for an intrasellar tumor. Surprisingly, this tumor, at first suspected to be a hormone-inactive pituitary adenoma, consisted in fact of sarcoid granulomatous tissue in the pituitary gland as found histologically. The morphological picture as seen in the cranial computed tomography was identical with that of an adenoma. This possibility had not previously been considered, although there had been an extracerebral manifestation of the sarcoidosis in the left ovary.
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PMID:Pituitary sarcoidosis. 233 7

This paper reports the occurrence of a rare, yet distinct pituitary adenoma which was surgically removed from a 42-year-old male with both clinical and biochemical evidence of acromegaly and mild hyperprolactinaemia. The monomorphic adenoma consisted of mature cells which were ultrastructurally indistinguishable from those of a prolactinoma. Electron immunocytochemistry, including a series of double-labelling techniques using selected colloidal gold particles as markers, indicated the presence of a pituitary adenoma in which the cells were capable of simultaneously producing growth hormone and prolactin and packaging them within the same secretory granule. This is thought to represent a mammosomatotroph cell adenoma.
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PMID:Clinical, biochemical and immunoelectron microscopical evidence of dual hormone production in a mammosomatotroph cell adenoma. 239 85

Serum glycoprotein hormone alpha-subunit levels were determined in 165 patients with pituitary adenomas. Elevated serum alpha-subunit levels were found in 17 patients (acromegaly, 5 of 58; prolactinoma, 6 of 56; nonfunctioning adenoma, 5 of 32; and ACTH-producing adenoma, 1 of 19), most of whom had normal serum TSH and gonadotropin levels. When TRH (0.5 mg) was injected iv in the 6 prolactinoma patients with elevated serum alpha-subunit levels, serum PRL and alpha-subunit levels increased in only 1 patient. Four acromegalic patients with high serum alpha-subunit levels received TRH; serum GH and alpha-subunit increased in 1 patient and did not change in 2, and only serum GH increased in the remaining patient. Oral administration of bromocriptine (5 mg), on the other hand, consistently decreased serum alpha-subunit and PRL levels in 2 patients with prolactinoma and alpha-subunit and GH levels in 1 acromegalic patient. When serum from 3 patients was subjected to Sephadex G-100 gel filtration, immunoreactive alpha-subunit eluted in a single peak, which emerged in fractions corresponding to [125I]TSH alpha. Concanavalin A (Con A) affinity chromatography revealed that the major portion of immunoreactive alpha-subunit was retained to Con A. A pituitary adenoma removed at surgery from a patient with acromegaly was studied in monolayer cell culture. Secretion of both alpha-subunit and GH from cultured adenoma cells was stimulated by TRH and suppressed by dopamine in a dose-dependent manner. Immunohistochemistry of the pituitary adenomas removed from patients with prolactinoma and acromegaly who had high serum alpha-subunit levels demonstrated alpha-subunit-containing cells as well as PRL- or GH-containing cells. These results suggest that elaboration of glycoprotein hormone alpha-subunit occurs without concurrent production of glycoprotein hormones in a substantial number of patients with pituitary adenomas and that alpha-subunit responses to stimuli in such adenomas are generally parallel with those of the concomitantly produced hormones.
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PMID:Secretion of glycoprotein hormone alpha-subunit by pituitary tumors. 243 40

The effect os SMS 201-995 (Sandostatin), a long-acting somatostatin analog, on different types of pituitary adenomas including alpha-subunit elevation is illustrated in this report. Treatment induced a fall in hCG levels in a woman with a pituitary adenoma producing only alpha-subunit. In 3 acromegalic patients, there was only a partial drop in GH and alpha-hCG. The same effect was observed in a woman with menopausal FSH and LH levels. SMS reduced plasma TSH and alpha-hCG in a case of thyrotropic adenoma. Two patients exhibiting FSH- and alpha-hCG-secreting adenomas did not respond to acute administration of SMS 201-995. More patients have to be treated before a definitive statement can be made on the usefulness of somatostatin analogs in the management of different types of pituitary adenomas.
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PMID:Plasma alpha-subunit levels during the treatment of pituitary adenomas with the somatostatin analog (SMS 201-995). 245 75

A 34-year-old man was found to have elevated thyroxine (T4), triiodothyronine (T3), calculated free T4, thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), and alpha subunits of TSH and FSH. A computed tomography scan of the head showed a 16-mm macroadenoma of the pituitary gland. There was no evidence of loss or excess secretion of other pituitary hormones. The large chromophobe adenoma was removed via a transphenoidal approach. The patient has been taken off all medication. Thyroid function has returned to normal and there has been no loss of pituitary secretory capacity of other pituitary hormones. The occurrence of a combined TSH- and FSH-secreting pituitary adenoma is rare; to the authors' knowledge, only one case has been documented in the literature.
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PMID:Hyperthyroidism with an FSH-and TSH-secreting pituitary adenoma. 248 37

A case of pituitary apoplexy causing pituitary hemorrhage with extension into the third ventricle is reported. The patient was a 73-year-old, obese female admitted with sudden onset of vomiting and impaired consciousness. Neurological examination revealed that she was stuporous, with marked neck stiffness and a dilated left pupil. A plain skull X-ray showed sellar enlargement and destruction of the dorsum sellae. Computed tomography demonstrated a high-density area in the third and lateral ventricles and a round, high-density mass in the suprasellar cistern. The patient died the next day. Autopsy revealed a large tumor in the sellar and suprasellar areas. The tumor and the hematoma within it compressed the floor of the third ventricle and passed through the lamina terminalis and the hypothalamic region. Histological examination disclosed a basophilic adenoma. The pituitary hemorrhage appeared to be the result of ischemia and necrosis within the pituitary adenoma caused by its acute expansion. The extension of the hematoma into the third ventricle was attributable to the large size of the tumor and its close adhesion to the floor of third ventricle.
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PMID:[Pituitary hemorrhage extending into the third ventricle. Case report]. 248 40

We used the reverse hemolytic plaque assay to study the dynamics of GH secretion by individual pituitary adenoma cells from eight acromegalic patients. There was a considerable variation between the adenomas with respect to the percentages of GH-secreting cells (25-78.5%) and also with respect to the amount of GH released per individual pituitary adenoma cell (mean plaque areas varying from 901-3559 micron 2). The GH plaque area frequency distributions from the adenoma cells were not normally distributed, but revealed a preponderance of small plaques, defined as those with areas smaller than the mean plaque area. The large plaques, that is those with areas larger than the mean plaque area, constituted 24-38% of the total cell population from different tumors and accounted for a large fraction (63-80%) of the total plaque area (the total amount of GH released by the adenoma cells). The somatostatin analog SMS 201-995 caused a shift in the GH plaque area frequency distributions toward smaller plaques, but had no effect on the overall percentages of GH plaque-forming cells in three of the five adenomas in which it was studied. This finding suggests that the adenoma cells from these patients that formed large plaques were preferentially inhibited by SMS 201-995. GHRH (studied in two adenomas) and TRH (studied in one adenoma) had no preferential effect on any subpopulation of adenoma cells. We conclude that GH secretion by individual somatotroph adenoma cells is highly variable both within and between adenomas and that SMS 201-995 has a preferential inhibitory effect on a subpopulation of adenoma cells in some adenomas.
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PMID:Heterogeneity of growth hormone (GH) release by individual pituitary adenoma cells from acromegalic patients, as determined by the reverse hemolytic plaque assay: effects of SMS 201-995, GH-releasing hormone and thyrotropin-releasing hormone. 249 40

Eight patients with active acromegaly due to GH-producing pituitary adenoma were studied. GH secretory dynamics in vitro was evaluated by adding GRF, CRF, or a somatostatin analog, SMS 201-995 to the perifusate of dispersed cells from tumors. A comparison was made between the data obtained in preoperative tests for GH secretion and those obtained in experiments in vitro. Before operation, the GRF test (100 micrograms, iv) resulted in no GH response in three of six patients examined. The CRF test (100 micrograms, iv) resulted in a paradoxical GH increase in two of the same six patients. In vitro studies performed on adenoma cells revealed that exposure to GRF (100 ng/ml) elicited an increase in GH in seven of eight patients examined. Exposure to CRF (100 ng/ml) caused an enhanced GH secretion in four of the same eight patients. There were cases in which GH response to these hypothalamic hormones was observed in vitro but not in vivo, whereas there was only one case in which CRF caused an increase in GH in vivo but not in vitro. Thus, GH secretory dynamics was not always the same in vivo and in vitro. The discrepancy could be ascribed to the different secretory status of hypothalamic hormone (e.g., GRF or somatostatin) in vivo in each acromegalic patient.
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PMID:Comparative in vivo and in vitro studies on abnormal GH secretion in patients with acromegaly. 249 48


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