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Stereotactic radiosurgery with the cobalt-60 gamma unit in the treatment of growth hormone-producing pituitary tumors.

Stereotactic radiosurgery on the pituitary given with the cobalt-60 gamma unit was used in the treatment of 21 patients with growth hormone (GH)-producing pituitary adenomas and acromegaly. All but one patient had locally invasive macroadenomas, and in the majority of cases, there was parasellar growth. Radiosurgery was the initial treatment for seven patients. Fourteen patients were previously treated by pituitary surgery, eight of whom had undergone conventional external pituitary irradiation as well. All patients had clinical signs of active acromegaly before radiosurgery. The radiation doses given to the previously untreated patients or those who only underwent surgery were 40 to 70 Gy in each of one to three irradiations. The patients with previous external irradiation received a lower dose of 30 to 50 Gy in each of one or two irradiations. The patients were observed during a period of 1 to 21 years from the first radiosurgical session. Two young patients had a clinical remission with a substantial decline of GH levels to near normal serum profiles. Another eight patients obtained reduction of GH levels and clinical activity. More than half of the patients (11 of 21) had minor or no effects from the treatment. There were no complications from the radiosurgery except the development of pituitary insufficiency in 2 of 13 patients who did not undergo previous conventional external irradiation. The remission rates were lower than the results previously reported by us for radiosurgery for Cushing's disease. This may be a result of the predominance in the present study of invasive macroadenomas and single treatments and to the lower radiation doses used in the patients who underwent conventional irradiation previously.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗

Coexisting primary empty sella syndrome and acromegally.

The 'empty' sells syndrome is now a more frequent diagnosis due to the increased use of pneumoencephalography in the evaluation of the enlarged pituitary fossa. This syndrome has also been classified into a 'primary' form in which there has been no prior pituitary irradiation or surgery, and a 'secondary' form in which the empty sella is found after such procedures. Most patients with the primary empty sella syndrome are found to have normal pituitary function while about 30% have varying degrees of hypopituitarism (Neelon et al., 1973). It is not widely appreciated, however, that the primary empty sella may harbour a pituitary tumour with resultant acromegaly. In this report we describe two such patients who presented with active acromegaly. This entity of pituitary tumour in a primary empty sella merits careful consideration since the coexistence of these two findings may influence the therapeutic approach that might otherwise be appropriate for the pituitary tumour.

Acromegaly↗

Failure of selective pituitary adenomectomy to cure acromegaly.

Complete selective pituitary adenomectomy for acromegaly may fail to cure the underlying endocrinopathy. A 40-year-old man who had acromegaly of ten-years duration was initially treated with pituitary irradiation eight years prior to surgery. Three years after irradiation his mean GH concentration decreased from 53 to 9.0 ng/ml, then subsequently increased, and was associated with development of severe hyperglycemia. A transsphenoidal microdissection was performed, and a discrete pituitary adenoma was visualized and totally removed at surgery. GH concentrations decreased from 46 to 5.0 ng/ml one week after surgery and to 3.0 ng/ml 10 months after surgery. Despite improvement postoperatively, the patient still demonstrated abnormal GH dynamics and responses to the GTT, abnormal nocturnal and random GH sampling, and abnormal responses to the L-dopa, apomorphine, and TRH stimulation tests. Acromegaly could be caused by either hypothalamic hyperfunction, an autonomous pituitary tumor, or both; but the latter would not explain the results obtained in this patient. This suggests that reduction of GH to normal concentrations following selective pituitary adenomectomy is not synonomous with curing acromegaly.

Acromegaly↗

Hypopituitarism and hyponatremia in a case with nasopharyngeal carcinoma.

We report a case of nasopharyngeal carcinoma (NPC) accompanied by hyponatremia and polyuria which was induced by tumor invasion into the pituitary gland. Magnetic resonance imaging showed the pituitary gland pushed upward by NPC. Hypopituitarism due to an intracranial tumor and the extracellular volume excess due to chemotherapy caused hyponatremia and polyuria. As the intracranial tumor was diminished by chemotherapy and irradiation, pituitary hormones were normalized. In patients with T4 NPC, pituitary-adrenocortical function should be endocrinologically evaluated before treatment.

Algorithms↗

GHRF test in acromegalic patients for the evaluation of therapeutic results.

We studied here the clinical significance of GHRF test in evaluating therapeutic results in patients with acromegaly. Three cases of acromegaly were studied at pre- and posttreatment. Case 1 is a 42 year old woman, and her plasma GH showed slight increases responding to TRH and arginine administration before therapy. Eleven years after the pituitary irradiation, basal plasma GH decreased to low normal ranges and showed no response to the above two agents. Only an insufficient increase in plasma GH was observed after GHRF injection. This case would have pituitary lesions not only in the tumor somatotrophs but also in the normal somatotrophs. Case 2 is a 38 year old man. His plasma GH showed a marked increase after TRH injection. To GHRF administration, however, no clear response was observed. After transsphenoidal adenomectomy, the aberrant responses to TRH was still observed despite the marked GH decrease to the near normal ranges. Interestingly, plasma GH became responsive to GHRF after the operation. It seems that the adenomectomy was inadequate in this case and the normal somatotrophs recovered the responsiveness to GHRF. Case 3 is a 53 year old woman, and she showed aberrant GH responses to TRH and to L-dopa. Her plasma GH clearly increased after GHRF injection. Postoperatively, the abnormal responses of plasma GH disappeared completely, while a normal GH response was observed following GHRF injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗

Cranial irradiation for cerebral and nasopharyngeal tumours in children: evidence for the production of a hypothalamic defect in growth hormone release.

A synthetic 29-amino acid analogue of human pancreatic GH-releasing hormone (GHRH(1-29)NH2) has recently been shown to stimulate the release of GH in normal subjects. We have studied the GH response to GHRH(1-29)NH2 in nine children irradiated for brain and nasopharyngeal tumours, who were not growing and were deficient in GH as assessed by insulin-induced hypoglycaemia. Serum GH rose in response to GHRH(1-29)NH2 in all the children, and in five the peak serum GH response was greater than 20 mu./l. The data suggest that when hypothalamo-pituitary irradiation results in GH deficiency, this is due to a failure of the synthesis or delivery of endogenous GHRH from the hypothalamus to the pituitary cells. It also suggests that it may be possible to treat such children using synthetic GHRH in place of exogenous GH.

Body Height↗

Cushing's syndrome: analysis of 188 cases.

From January 1962 through April 1988, 188 patients with Cushing's syndrome were hospitalized at the Veterans General Hospital. Iatrogenic Cushing's syndrome was found in 123 (65.4%) of the patients. The other 43 patients (22.9%) had excess secretion of adrenocorticotropin (ACTH) and 22 patients (11.7%) had benign or malignant adrenocortical tumors. The clinical features and the functional reserve of the adrenal glands in those patients with iatrogenic Cushing's syndrome were evaluated. A retrospective analysis of the diagnostic rate of the various endocrine evaluations and the radiological examinations was also carried out. Four approaches were used in the management of Cushing's syndrome: (1) pituitary surgery, (2) pituitary irradiation, (3) adrenal surgery, and (4) drug therapy. Both the clinical and hormonal responses to these four management types were evaluated. The endocrinological, radiological, surgical and pathological experiences of 25 patients with Cushing's disease treated with pituitary surgery are presented. Five patients (20%) had an atypical endocrine pattern (20% false-negative). Twenty-four patients received a pituitary CT scan and 16 patients (66.7%) had positive CT findings. Of these 25 patients, 19 had pathology-proven microadenomas (less than 1cm), one had macroadenoma (greater than 1cm) and 5 had no evidence of adenomatous tissue. Among the 22 patients with adrenal Cushing's syndrome, 4 (18%) were suffering from adrenocortical carcinoma and 18 (82%) with benign adrenal tumors. The incidence of left adrenal adenoma was approximately twice that of right adrenal adenoma. The cure rate of adrenocortical adenoma by surgical treatment with unilateral adrenalectomy was excellent, but for adrenocortical carcinoma was poor.

Adolescent↗

Hyperthyroidism due to a thyrotropin-secreting pituitary adenoma. Studies of thyrotropin and subunit secretion.

A 58-year-old man had symptoms of hyperthyroidism and congestive heart failure. While hyperthyroid, his serum thyrotropin (TSH) level was inappropriately elevated at 6.1 microunits/mL. The molar ratio of alpha subunit to TSH was 2.5, suggesting the presence of a TSH-secreting pituitary tumor. Further evaluation disclosed an enlarged sella turcica with posterior erosion, and an intrasellar mass was visualized on computed tomographic scan. Neither serum TSH nor alpha subunit levels became elevated after administration of thyrotropin-releasing hormone, nor were they suppressed by a dopamine infusion. Serum TSH but not alpha subunit levels rose during antithyroid drug therapy. Estrogens produced a partial reduction in serum alpha subunit concentration (presumably reflecting the nontumorous gonadotroph contribution to circulating alpha subunit). Dexamethasone completely suppressed serum TSH level but had no effect on the alpha subunit level, suggesting a differential feedback of glucocorticoids on TSH and alpha secretion. The patient was treated with pituitary irradiation rather than surgery because of his underlying heart disease.

Adenoma↗

Long-term effect of 90Y pituitary implantation in acromegaly.

This report examines the long-term trends in GH levels and pituitary function in a group of 38 acromegalic patients who were selected insofar as we were able to follow them up for more than 10 years after a single dose of 90Y interstitial pituitary irradiation as the sole treatment. Mean serum GH had fallen from 106 to 24 mIU/l within 3-6 months and then slowly declined to 4 mIU/l after 10 years. GH levels of less than or equal to 5 mIU/l during a 50 g oral glucose tolerance test were obtained in 8% of patients at 3-6 months and in 18% at 1 year, the cumulative percentage increasing to 53% at 10, and 76% at 14 years. The percentage of patients requiring hormone replacement therapy rose from nil pre-implant to 16% by 3-6 months, and then slowly increased to 39% by 14 years. Serial coned radiographs of the pituitary fossa were available for 32 patients. By 10 years, 16 showed thickening of the dorsum sellae and/or reduction of at least one diameter by 3 mm. Concerning symptoms, all 29 patients whose GH level fell to less than or equal to 5 mIU/l showed improvements, 22 becoming asymptomatic. Seven patients with lesser falls in GH levels (from a mean of 193 to a mean of 15 mIU/l) all improved, one becoming asymptomatic. Two showed no variation. These results show that 90Y pituitary implants have a cumulative effect over the years in inducing remission and hypopituitarism in acromegalic patients, the early decline in GH levels being swifter than from other forms of irradiation.

Acromegaly↗

Cushing's syndrome.

Cushing's syndrome remains one of the most challenging problems in clinical endocrinology. Cushing's disease is caused in the majority of cases by basophil pituitary microadenomas which may be successfully treated by trans-sphenoidal hypophysectomy. Treatment with metyrapone or o,p'-DDD can always induce a clinical remission but not a cure, and neurotransmitter therapy may be effective in a minority of cases. Pituitary irradiation cures about half of cases in the long-term and may be used for surgical failures. Tumours producing ectopic ACTH are frequently benign, small and occult and may produce a syndrome clinically indistinguishable from Cushing's disease. Biochemical investigations cannot absolutely distinguish pituitary from ectopic sources of ACTH and therefore body CT scanning and percatheter venous sampling are essential diagnostic investigations. Tumour localization may result in resection and complete cure, although even small tumours may have a malignant potential. Adrenal tumours are readily diagnosed by plasma ACTH measurement and adrenal CT scanning. Adrenal adenomas are cured by adrenalectomy. Carcinomas may be treated by a combination of adrenalectomy, radiotherapy and o,p'-DDD, but long-term prognosis is poor.

Adrenal Cortex Hormones↗

Surgery combined with dopamine agonists versus dopamine agonists alone in long-term treatment of macroprolactinoma: a retrospective study.

We retrospectively analysed the long-term treatment results (median 8 years) of 31 patients with macroprolactinoma. 17 patients were treated by pituitary surgery (group 1) followed by long-term dopamine agonist therapy whereas 14 patients received long-term dopamine agonist therapy alone (group 2). 2 patients of group 1 and 1 patient of group 2 had external pituitary irradiation because of progressive disease. The two groups were comparable with respect to age, gender and initial prolactin (PRL) levels. At the end of the observation period dopamine agonist dosage could be reduced by 50% in group 1 and by 39.3% in group 2. Pituitary function did not change substantially during therapy. Complete remissions (no visible tumour in CT or MRI, normal PRL levels under current dopamine agonist medication) were achieved in 23.5% of group 1 vs. 21.4% of group 2, partial remissions (reduction of PRL and tumour size) in 35.3% vs. 64.3%, stable disease in 23.5% vs. 7.1% and progressive disease in 17.7% vs. 7.1% (differences not significant). Visual field defects showed 28.4% remissions (complete and partial) in group 1 versus 50% in group 2. Dopamine agonist therapy could be stopped definitively in only 1 patient of group 2 with an invasive macroprolactinoma. Initial surgical reduction of tumour load followed by medical therapy does not seem to guarantee a better long-term outcome than dopamine agonist therapy alone if the patient responds to and tolerates dopamine agonist therapy. Surgery should be reserved for non-responders, drug-intolerant or non-compliant patients, and for those with acute severe neurological compromise.

Adolescent↗

Transnasal microsurgery in children and adolescents with Cushing's disease.

OBJECTIVE: Transnasal adenomectomy is the treatment of choice for Cushing's disease. We review the diagnostic peculiarities, specific surgical problems, and outcome of children and adolescents with Cushing's disease. METHODS: We report on our series of 55 consecutive children and adolescents (range, 4.2-18.9 yr [mean age, 14.4 yr]; female:male = 1.1:1.0; mean follow-up, 54.5 +/- 38.6 mo [standard deviation]) with Cushing's disease on whom we performed surgery since 1980. The indication for transsphenoidal surgery is based on endocrinological parameters and not on neuroradiological findings. RESULTS: Detection rate of the tumor site was 22% using computed tomography and 33% using magnetic resonance imaging. Only 7 of 13 interpetrosal adrenocorticotropic hormone gradients obtained during inferior petrosal sinus sampling correctly lateralized the tumor site preoperatively (53.8%). In cases of incomplete sphenoid pneumatization, adequate exposure is achieved by drilling. The tumor finding rate is 98%. The remission rate is 100% when two early subsequent operations are included. The recurrence rate for 45 primary operations with follow-up of at least 1 year is 15.5%. Seven of nine subsequent operations for recurrent hypercortisolism were successful. One patient needed three more operations until hypercortisolism subsided; one patient achieved remission after additional pituitary irradiation. The surgical morbidity was low in this series, which consisted of two cerebrospinal fluid fistulas. The incidence of hypopituitarism after primary operations (10.3%) is significantly lower than after subsequent operations (45.5%). CONCLUSION: Direct transnasal submucosal surgery for Cushing's disease is successful, and pituitary function can be preserved in most of these young patients.

Adenoma↗

The Cushing syndromes: changing views of diagnosis and treatment.

Cushing's syndrome is the common clinical presentation of three unique disorders that give rise to hypercortisolism. In most cases neoplasms underly each of these disorders. Clinical features are highly variable and not accounted for by cortisol alone; indeed, the multihormonal basis for much of the clinical syndrome remains uncertain. Demonstration of sustained, excessive cortisol production is essential and depends on a pattern of repeated measurements and several different procedures. Plasma adrenocorticotropin, although not helpful in establishing the diagnosis, has proved valuable in differentiating the three major entities that cause hypercortisolism. The renewed significance of pituitary microadenomas and their improved detection by sella tomography has accompanied recent, impressive advances in transsphenoidal microsurgery. This may become the preferred treatment for pituitary Cushing's syndrome in the adult, particularly where the appropriate equipment and skills are available; for children, external pituitary irradiation seems to offer safe and effective therapy.

Adolescent↗

[FSH, LH, prolactin and testosterone levels in peripheral blood and urinary excretion of 17-ketosteroids and 17-hydroxycorticosteroids in patients after removal of chromophobe adenoma of the pituitary gland].

The aim of the study was clinical evaluation of a new marker of pituitary tumours--the alpha subunit of glycoprotein hormones. The studies were performed in 152 patients with manifestations of intersellar tumours; an elevated serum alpha subunit concentration was found in 49 of these cases. The determinations of alpha subunit were performed by double antibody radioimmunoassay. Iodination of alpha subunit was made by chloramine T technique with subsequent purification of Ultrogel AcA54 column. The remaining pituitary hormones were also determined by radioimmunoassay. The incidence of pituitary tumours of alphoma type was 30 percent. Tumours occurred frequently in association with an increased serum growth hormone and manifestations of acromegaly, less frequently with hyperprolactinemia and signs of prolactinoma. Following neurosurgery of 60Co pituitary irradiation hypopituitarism was of high occurrence.

17-Hydroxycorticosteroids↗

External irradiation of macroinvasive pituitary adenomas with telecobalt: a retrospective study with long-term follow-up in patients irradiated with doses mostly of between 40-45 Gy.

PURPOSE: Published dose recommendations for radiotherapy in patients with pituitary macroadenomas vary. Therefore, we retrospectively analyzed the results in our patients from the treatment period 1973-1992. METHODS AND MATERIALS: From a total of 89 patients with macroinvasive adenomas, 66 received radiation therapy immediately following subtotal surgical removal (combined treatment modality), and 22 were irradiated as primary treatment or after surgical recurrence. Only one patient was reirradiated. The surgical interventions have been performed by the same surgeon. For the majority of patients (79 out of 89) with a mean follow-up of 8.1 years (0.5-19 years) the total tumor dose ranged between 40-45 Gy at a dose per fraction of 1.8-2.25 Gy. All patients had bilateral opposed fields with telecobalt. Eleven patients had an additional arc rotation. RESULTS: The 10-year progression-free survival for all 89 patients independent of treatment modality was 88.1%. The 10-year progression-free survival for patients treated by surgery and adjuvant radiation therapy (40-45 Gy at 1.8-2.25 Gy, 60 out of 79) was 90.3%, and for radiation therapy alone (40-45 Gy at 1.8-2.25 Gy, 19 out of 79), 100% (p = 0.32). The prognostic factors for progression-free survival were the subtype of adenoma, the presence of visual symptoms at the time of diagnosis, the suprasellar extension, and the initial hormone levels. The presence of infiltration of adenoma cells in the basal dura or in the mucosa of the sinus sphenoidalis do not represent prognostic factors showing the special biological behavior of pituitary adenomas. Signs of x-ray-induced cerebral necrosis have not been observed in any patient. Long-term visual complications developed in four patients. This could be due to scar formation in the treated region, which can compress the optic nerve and provoke disturbance similar to an empty-sella syndrome. The latter occurred prevalently years after treatment, even though surgical methods of sellar plugging were used. The incidence of hypopituitarism after combined treatment modality at time of last follow-up (irradiated between 40-45 Gy at 1.8-2.25 Gy) was low (36%, 21 out of 60). CONCLUSION: In patients with pituitary macroadenomas, radiotherapy with a total dose of 40-45 Gy at 1.8-2.25 Gy per fraction resulted in a high local tumor control without serious morbidity.

Adenoma↗

The new highly sensitive adrenocorticotropin assay improves detection of patients with partial adrenocorticotropin deficiency in a short-term metyrapone test.

This study was designed to evaluate a short term metyrapone test using a highly sensitive (HS) IRMA ACTH assay and to evaluate the usefulness of a morning ACTH level as a screening test for partial ACTH deficiency. ACTH, 11-deoxycortisol and cortisol levels were evaluated over four hours in the morning after a single 40 mg/kg oral dose of metyrapone was administered at 0800 hours. 26 control children and 32 possibly pituitary deficient patients were evaluated. Based on 11-deoxycortisol levels alone, 17 of the patients passed the test, 11 patients failed the test and the result was inconclusive in four patients (12.5%). Evaluation of the increase in ACTH levels (delta ACTH) following metyrapone identified three of the above four with partial ACTH deficiency. The delta ACTH was consistent with the 11-deoxycortisol results in the remainder of patients. There was no difference in morning ACTH levels between controls and patients with partial ACTH deficiency. The measurement of ACTH using the HS IRMA assay, increases the sensitivity of the metyrapone test in detecting patients with partial ACTH deficiency. This test may be used safely in pediatric patients on a repetitive basis, especially in those children who may have progressive ACTH failure following hypothalamic-pituitary irradiation.

Adolescent↗

[Anterior pituitary hypersecretion syndromes].

Anterior pituitary hypersecretion can be due to abnormal hypothalamic regulation, decreased peripheral hormone feedback or pituitary tumor. In some cases hypersecretion gives rise to a typical clinical syndrome involving acromegaly, hyperprolactinemia, and excess corticotropin (ACTH). The etiology of acromegaly is a growth hormone (GH)-secreting pituitary tumor in the vast majority of cases. Hyperprolactinemia and excess cortisol, however, may be due to many causes among which prolactin (PRL)- and ACTH-secreting pituitary tumors are not frequent. Glycoprotein-secreting pituitary tumors, especially gonadotropin (LH and FSH) and free subunits usually do not cause a typical excess hormone syndrome. Perhaps for this reason they are seldom recognized clinically, although histopathological studies are increasingly disclosing the gonadotrope nature of many pituitary tumors. Mixed hormonal secretions are common. When pituitary hormone secretion can be selectively suppressed by medical therapy, a significant reduction of tumor size is by no means rare. In other cases, pituitary irradiation or surgery, or even treatment aimed at a peripheral target gland, may be necessary.

Acromegaly↗

Nonpuerperal galactorrhea and hyperprolactinemia. Clinical findings, endocrine features and therapeutic responses in 56 cases.

The clinical and endocrine features, and the responses to different treatment modalities, were examined in 56 patients with galactorrhea and/or hyperprolactinemia after a two month to six year follow-up period. A pituitary adenoma was diagnosed in 17 patients. A prolactin-cell adenoma was identified histologically in eight patients. Other etiologic factors were myxedema (two patients), phenothiazine ingestion (six patients) and breast manipulation (four patients). In 27 patients, including three with abnormalities of the sella turcica, no causal factor was found, and their condition was labelled as dysfunctional in origin. Symptoms were preceded by childbirth in 11 patients and by estrogen-progestin contraception in 22; pituitary adenomas were discovered in both groups in approximately the same frequency (30%) as in the over-all study group. Aside from roentgenographic studies, as well as visual field perimetry in a few cases, a serum prolactin level above 100 ng/ml was the only indicator of a pituitary prolactin-cell adenoma. Prolactin-suppression tests (L-DOPA and 2alpha-Br-ergocryptine) were found to be of no value in discriminating between tumoral and dysfunctional conditions. No significant alterations in prolactin levels occurred after water loading irrespective of basal levels or the nature of the pathologic process. Selective pituitary tumor excision (eight patients) was followed by rapid normalization of prolactin levels and disappearance of clinical abnormalities. Conversely, after pituitary irradiation (eight patients), improvement tended to be slower. Treatment of infertility in those patients without an apparent organic lesion was more successful with 2alpha-Br-ergocryptine (three of three) than with clomiphene (two of seven). Pregnancies following the administration of drugs or after surgical treatment were uneventful. Since follow-up resulted in the early diagnosis of pituitary tumors from seven to 56 months after initial investigation, and since no diagnostic tools are currently available which help to discriminate between tumoral and dysfunctional conditions before abnormalities become evident on roentgenograms, prolonged observation of these patients remains essential.

Adenoma↗