Large Pituitary Tumors Research Articles

Reduced Size of a Hormonally Silent Pituitary Adenoma during Treatment with CV 205-502, a New Dopamine Agonist Mainly Stimulating D2 Receptors

Abstract A 39-year-old woman with secondary amenorrhea and visual field defects underwent craniotomy for a large pituitary tumor that was hormonally silent according to measurement of plasma hormone levels and immunohistochemical analysis. During the preoperative investigation, bromocriptine was administered for 1 month, but there was no change in the tumor size as seen on computed tomographic scans. One month after surgery, visual field defects recurred, and a tumor mass comparable to the preoperative state was found on computed tomographic scan. The tumor size gradually diminished during treatment with CV 205-502, a tricyclic benzoquinoline which stimulates mainly D2receptors and is better tolerated than bromocriptine. The visual fields were completely normalized after 3 months of treatment with the drug, and surgical management of the tumor mass was no longer considered to be necessary. Thus, as in many similar cases, the hormonally silent pituitary tumor in this patient proved unresponsive to bromocriptine treatment. In contrast. the tumor was reduced by therapy with CV 205-502, a drug that is better tolerated and might permit a more intense stimulation of D2receptors.

Reduced size of a hormonally silent pituitary adenoma during treatment with CV 205-502, a new dopamine agonist mainly stimulating D2 receptors

A 39-year-old woman with secondary amenorrhea and visual field defects underwent craniotomy for a large pituitary tumor that was hormonally silent according to measurement of plasma hormone levels and immunohistochemical analysis. During the preoperative investigation, bromocriptine was administered for 1 month, but there was no change in the tumor size as seen on computed tomographic scans. One month after surgery, visual field defects recurred, and a tumor mass comparable to the preoperative state was found on computed tomographic scan. The tumor size gradually diminished during treatment with CV 205-502, a tricyclic benzoquinoline which stimulates mainly D2 receptors and is better tolerated than bromocriptine. The visual fields were completely normalized after 3 months of treatment with the drug, and surgical management of the tumor mass was no longer considered to be necessary. Thus, as in many similar cases, the hormonally silent pituitary tumor in this patient proved unresponsive to bromocriptine treatment. In contrast, the tumor was reduced by therapy with CV 205-502, a drug that is better tolerated and might permit a more intense stimulation of D2 receptors.

Endocrine function in patients with large pituitary tumors treated with operative decompression and radiation therapy.

Large pituitary tumors are still a common problem. Thirty consecutive patients underwent operative decompression and radiation therapy for large sellar and suprasellar tumors. They were studied prospectively in terms of their endocrine outcome. Ten of the patients had panhypopituitarism both before and after treatment. The other 20 patients had partial hormonal deficits prior to treatment. Ten (50%) of the 20 patients who had partial preoperative deficits went on to develop delayed onset of worsening in their endocrine function; 9 of the 10 developed panhypopituitarism, and 1 patient developed decreased thyroid function. The mean time from surgery until the onset of delayed worsening in endocrine function was 26.1 months. The mean age of those patients who developed delayed onset of worsening in pituitary function was significantly higher than that of those who did not develop further hormonal loss (40.5 +/- 3.1 years versus 52.0 +/- 4.1 years, P less than 0.05). None of the 10 patients with delayed onset of worsening in pituitary function had anatomical evidence by computed tomographic scan of tumor recurrence. Delayed onset radiation effect is the most likely cause of the late onset of worsening in endocrine function.

Endocrine function in patients with large pituitary tumors treated with operative decompression and radiation therapy

Endocrine function in patients with large pituitary tumors treated with operative decompression and radiation therapy

Unusual presentation of a large pituitary tumour in relation to diving

A case of necrosis of a pituitary tumour occurring in the context of diving is described. The presenting features and subsequent course suggested a brain stem vascular event. The tumour was not detected by routine computerized tomographic scanning, but was identified with magnetic resonance imaging. The possible pathophysiological mechanism is discussed.

Therapeutic applications of bromocriptine in endocrine and neurological diseases.

Bromocriptine, or 2-bromo-alpha-ergocryptine, is a semisynthetic ergot alkaloid. The basis of its therapeutic application in endocrine and neurological diseases is its action as a potent dopamine agonist. Its ability to inhibit prolactin secretion has led to its successful use in suppression of puerperal lactation and in the treatment of pathological hyperprolactinaemia causing galactorrhoea, infertility or hypogonadism. It has been shown to be safe in pregnancy. The ability of bromocriptine to reduce the size of large prolactin-secreting pituitary tumours has resulted in the recovery of pituitary function and correction of visual field defects. Bromocriptine is less effective in acromegaly but is useful as adjuvant therapy to radiotherapy and/or surgery which has been the standard mode of treatment. It has been shown to be efficacious either alone or in combination with levodopa in the treatment of Parkinson's disease. Therapy with low doses appears to be effective and is associated with a significantly reduced incidence of side effects. The successful use of bromocriptine has also been reported for the treatment of non-functioning pituitary tumours, premenstrual syndrome, cyclical mastalgia, luteal phase insufficiency and portal-systemic encephalopathy, although its role in the treatment of these latter disorders remains uncertain until more extensive and adequately controlled trials have been conducted.

Gonadotropin-Producing Pituitary Adenoma in a Man with Long-Standing Primary Hypogonadism*

Pituitary adenomas that secrete gonadotropins are generally believed to arise spontaneously rather than as a response to chronic primary gonadal failure. However, two women who were found to have gonadotroph adenomas several years after ovarian ablation have been reported. We describe a middle-aged man who developed bitemporal hemianopia and was found to have a large pituitary tumor 35 yr after castration. He had never received any replacement therapy. The tumor was considered to be a primary gonadotroph adenoma, rather than secondary gonadotroph hyperplasia, on the basis of its secretory capabilities, its reticulin patterns, and its specific immunostaining for human FSH beta, human LH beta, and alpha-subunit. Furthermore, the tumor did not decrease appreciably in size after 12 months of testosterone treatment, although plasma gonadotropin levels decreased. Unless the association of primary gonadal failure with a gonadotroph adenoma was coincidental, it suggests that some human gonadotroph adenomas may be secondary to failure of the gonads.

Craniotomy versus transsphenoidal excision of large pituitary tumors

Craniotomy versus transsphenoidal excision of large pituitary tumors

Magnetic resonance imaging of the pituitary gland

Magnetic resonance imaging (MRI) was performed on 22 patients with a wide spectrum of pituitary disease and on 17 control subjects, in order to determine whether MRI is useful in localising and determining the extent of involvement of large and small pituitary tumours. The results indicate that MRI, with an 0.5 T superconducting magnet (Elscint, Israel), can be used to visualise large pituitary tumours and to determine the extent of parasellar and suprasellar involvement. The 'empty sella' syndrome can also be easily and confidently diagnosed. Some microadenomas can be visualised despite the relatively thick slices (0.7 cm) used in this study. These findings suggest that MRI in its current state of development is very useful in evaluating large pituitary lesions. With further technical refinements, improving the spatial resolution and decreasing slice thickness, this technique may come to be of some importance in the evaluation of pituitary microadenomas.

The effect of dopamine agonist therapy on large functionless pituitary tumours.

Fifteen patients (12 male) with large pituitary tumours and serum prolactin levels below 1000 mU/l were given dopamine agonist therapy (bromocriptine, mesulergine or pergolide) for a mean of 9 months (range 3-36 months). Serum prolactin became undetectable in all. Despite this, significant suprasellar extensions and any associated neurological defect remained in 14 patients, who therefore were referred for surgery. In one patient there was evidence of spontaneous pituitary infarction unrelated to dopamine agonist therapy. At operation 12 patients had apparently functionless pituitary adenomas which failed to immunostain for prolactin, one had an epidermoid cyst and one a Rathke's pouch cyst. We conclude that patients with large pituitary tumours and only a mildly elevated serum prolactin are unlikely to have prolactinomas, and that such tumours are not likely to show significant tumour shrinkage with medical treatment with dopamine agonists.

Assessment by computed tomography of the response of pituitary macroadenomas to bromocriptine

Eleven patients with large pituitary tumours and with extrasellar extension were studied prospectively to assess the response of these tumours to bromocriptine. Five out of the six patients with high serum prolactin due to prolactinomas showed rapid and dramatic reduction in tumour size when treated with bromocriptine. In contrast, none of the five patients with non-functioning tumours showed any change in tumour size on computed tomography.

Pregnancy After Bromocriptine-Induced Reduction of an Extrasellar Prolactin-Secreting Pituitary Macroadenoma

In patients with a large prolactin-secreting pituitary adenoma, a marked reduction in tumor size may be achieved with bromocriptine therapy. However, before consideration of pregnancy, surgical removal of the lesion usually is advised. A 36-year-old woman with a large extrasellar pituitary macroadenoma was treated with bromocriptine, 10 mg/day, which resulted in dramatic reduction of the tumor mass. Subsequently, she became pregnant and drug therapy was maintained throughout gestation. This case illustrates the use of bromocriptine in the management of large prolactin-secreting pituitary tumors and the necessity for adequate radiologic follow-up.

Twenty-four hour secretory pattern of prolactin in hyperprolactinaemic patients with pituitary micro- and macroadenomas.

No nocturnal increase of prolactin (Prl) secretion during sleep has reportedly been discernible in most cases of hyperprolactinaemic patients with pituitary tumour. However, subjects previously evaluated, were in the majority, patients with large pituitary tumour. In the present study, 24 h secretory pattern of Prl was evaluated in 4 hyperprolactinaemic women with pituitary microadenoma and in 4 hyperprolactinaemic women with pituitary macroadenoma. Nocturnal increase of Prl secretion was observed in patients with microadenoma, but not in patients with macroadenoma. The nocturnal increase of Prl secretion in patients with microadenoma may reflect the function of the adenoma cells, and may suggest that the basic central nervous system programme governing Prl secretion in normals is qualitatively preserved in these patients. Alternatively, the nocturnal increase of Prl secretion may reflect the function of the normal lactotrophs remaining in these patients.

Combined Supra-Infrasellar Approach for Large Pituitary Tumors

Abstract A combined supra-infrasellar approach for the resection of very large pituitary tumors is described. We think that it is superior to either the transsphenoidal or the intracranial approaches to these difficult tumors.

Combined Supra-Infrasellar Approach for Large Pituitary Tumors

A combined supra- infrasellar approach for the resection of very large pituitary tumors is described. We think that it is superior to either the transsphenoidal or the intracranial approaches to these difficult tumors.

Increased Susceptibility of Livers of Aged F344/NCr Rats to the Effects of Phenobarbital on the Incidence, Morphology, and Histochemistry of Hepatocellular Foci and Neoplasms<xref ref-type="fn" rid="FN2">2</xref><xref ref-type="fn" rid="FN3">3</xref>

Aged (875 days old) and young 42 days old) male F344/NCr rats were given sodium phenobarbital (PB) in drinking water for periods up to 233 days. Groups of aged rats were killed at 30 or 60 days or allowed to live their normal life-span, and the cause of death was determined. Young rats killed after 30, 60, and 150 days of PB exposure. Hepatocellular foci were classified into basophilic, eosinophilic, or vacuolated types according to morphologic appearance of the hepatocyte cytoplasm and were characterized by histochemical methods for the presence of gamma-glutamyl transpeptidase (GGT). The most common contributing causes of death for rats in both groups were large granular lymphocyte (LGL) leukemia and pituitary tumors. PB decreased the incidence of LGL leukemia but increased the incidence and multiplicity of hepatocellular GGT-positive foci, eosinophilic foci, and eosinophilic hepatocellular adenomas. GGT-positive eosinophilic foci increased in diameter and volume, but not in number, after appearing early in the experiment. Hepatocellular basophilic foci and neoplasms in aged control rats were usually GGT-negative and did not appear to respond to dietary PB. GGT-positive foci were seen in aged control rat livers and were composed of vacuolated amphophilic hepatocytes that differed morphologically from hepatocytes in naturally occurring liver tumors. Young rats given PB had few GGT-positive foci by 150 days on test. Aged rat livers were thus more sensitive to the effects of PB than were livers of young rats.

The regression of oestradiol-induced pituitary tumours in the rat.

Wistar rats of both sexes were implanted subcutaneously with oestradiol pellets (25 mg). The pellets were removed in two groups of animals after 120 and 220 days of implantation; in other animals the pellets were left for 230 and 370 days. The animals in whom pellets were left implanted all had large pituitary tumours. The animals from whom the pellets had been removed had pituitaries larger than normal, but much smaller than those in which the implants had been left. The results suggest that oestradiol-induced pituitary tumours are totally hormone-dependent and are not autonomous neoplasms. Oestradiol-induced testicular atrophy was also reversible.

Cushing's Disease in a Patient With a 'Nonfunctioning' Pituitary Tumor

A 40-year-old woman had visual loss and a large nonfunctioning pituitary tumor. After partial surgical resection and radiation treatment, clinical and biochemical evidence of Cushing's disease developed. The pituitary source of her adrenocorticotropic hormone hypersecretion was documented on selective venous sampling. After 18 months of medical therapy with metyrapone and aminoglutethimide, the patient experienced a spontaneous remission of her hypercortisolism. A "nonfunctioning" pituitary tumor has a hypersecretory potential.

Bromocriptine in management of large pituitary tumours.

Bromocriptine in management of large pituitary tumours.

Points: Bromocriptine in management of large pituitary tumours

Points: Bromocriptine in management of large pituitary tumours