Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Therapy with 910 MeV alpha particles provides a treatment with no mortality and an extremely low morbidity and has been highly successful in the control of pituitary hormone hypersecretion and tumor growth. It is possible to deliver radiation doses to the pituitary gland that are sufficiently high to inhibit or destroy the tumor cells that cause abnormal secretory activity without damaging the surrounding structures. The data demonstrate the effectiveness of this form of treatment in acromegaly, non-functioning pituitary tumors, prolactin secreting adenomas, Cushing's disease and Nelson's syndrome.
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PMID:Heavy particle therapy: pituitary tumors. 22 2

Nelson's syndrome is generally regarded as an unusual sequela of primary bilateral adrenalectomy when performed for Cushing's disease. It is classically defined by cutaneous hyperpigmentation, considerably elevated adrenocorticotropic hormone (ACTH) levels, and an enlarged sella turcica. In this report, we present three cases initially treated by transsphenoidal sellar exploration for Cushing's disease. In two of these cases, remission of hypercortisolism did not occur after the initial pituitary exploration. A microadenomectomy was performed in one case and, in the other, no microadenoma was found. In both, Nelson's syndrome occurred after adrenalectomy. A second transsphenoidal operation and radiotherapy were required to control tumor growth. In another case, transsphenoidal adenomectomy of an ACTH-secreting tumor initially led to a remission of hypercortisolism for 4 years, but recurrent Cushing's disease necessitated adrenalectomy, and again Nelson's syndrome occurred. The documentation of a pre-existing ACTH-secreting basophilic pituitary microadenoma before adrenalectomy, as seen in two of our cases, has not been previously reported, and these observations of "non-classical" courses have major implications for the pathophysiology of Nelson's syndrome.
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PMID:Observations on the pathophysiology of Nelson's syndrome: a report of three cases. 217 67

Pituitary adenomas may produce local endocrine and neurological effects, as well as systemic metabolic complications due to hormonal hypersecretion. Medical therapy with pharmacological agents has been developed and is based on the neurotransmitter regulation of normal pituitary hormonal secretion. 189 patients with secretory pituitary adenomas underwent medical therapy for the hypersecretory state. 156 of these were prolactin-secreting adenomas, 16 of which were in males. The response of bromocriptine was almost universal with lowering of serum prolactin and reversal of the clinical symptoms, as well as tumor shrinkage of most large adenomas with suprasellar extension. 23 patients with acromegaly were treated with bromocriptine, with 11 noting clinical improvement, and decreased tumor size in two. Five patients with Cushing's disease were treated with cyproheptadine, with only one showing a biochemical and clinical improvement. Two patients with Nelson's syndrome each had progressive tumor growth stabilized with cyproheptadine and bromocriptine in one, and sodium valproate in the other. There appears to be a role for medical therapy in the majority of prolactin-secreting pituitary tumors, some growth hormone secreting pituitary tumors, and selected adrenocorticotropin secreting-pituitary tumors.
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PMID:The medical treatment of the hypersecreting pituitary gland. 299 35

In all stereotactic irradiation procedures, a high dose is delivered to a relatively small target volume. Whether fractionated stereotactic radiotherapy is preferable (based on a therapeutic ratio) or a radiosurgical method (aiming at the precise and complete destruction of a tissue volume) depends on the definition and composition of the target. The methodologies can be grouped in closed-skull external focussed beam stereotactic radiosurgery/radiotherapy and in stereotactic implantation/injection of radiation sources. Although originally developed to treat functional disorders of the brain, stereotactic radiosurgery has been used most successfully for over 4 decades to treat cerebral arteriovenous malformations. Complete obliteration ranges from 30 to 50% after 1 year are reported. At 2 years the results range from 72 to 90%. Clearly the outcome is influenced by patient selection. In the treatment of acoustic neurinomas follow-up data of larger series of radiosurgery show that the treatment performed under local anesthesia on an outpatient basis becomes comparable with the best microsurgery data. Using multiple isocenters and MR localization tumor growth control is achieved in more than 90% of cases, with hearing preservation of approximately 50%. Pituitary tumors with Cushing's syndrome, acromegaly, Nelson's syndrome, prolactinomas and nonsecreting adenomas have been treated with various stereotactic irradiation methods. Further refinement of both localization techniques, dose distribution and beam manipulation will make radiosurgery an attractive modality because of its noninvasive character and low morbidity. Only a small subgroup of patients with low-grade gliomas are candidates for stereotactic localized irradiation treatment, namely those with circumscribed tumors with only limited spread of tumor cells into the periphery. For this subgroup, which usually comprises not more than 25% of all low-grade gliomas, the results from interstitial radiosurgery compete with surgical resection. Apart from the possibility to define the borders of the treatment volume with serial stereotactic biopsies, there are dosimetric advantages of interstitial radiosurgery. Local single high-dose treatment remains controversial for highly malignant infiltrative tumors, and significant treatment benefit remains to be documented. Radiosurgery can be used to effectively treat solitary brain metastases with less invasiveness and dissection of normal tissue, and with lower morbidity and less expense than open surgery.
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PMID:Stereotactic radiation therapy and radiosurgery. 762 37

Radiosurgery aims at the precise destruction of small, defined volumes of tissue by employing ionizing radiation energy. Its methodologies may be subdivided into closed-skull, external focussed beam radiosurgery, and interstitial radiosurgery (brachytherapy). Focussed beam stereotactic radiosurgery has been used successfully for over two decades to treat cerebral arteriovenous malformations. Complete obliteration ranges from 30% to 50% after one year. After two years, obliteration is observed in up to 90% of patients. Outcome, however, is influenced by patient selection. In the treatment of acoustic neurinomas, follow-up data of larger series show that radiosurgery performed under local anesthesia on an out-patient basis is competitive with microsurgery data. Using multiple isocenters and magnetic resonance localization, tumor growth control is achieved in more than 90% of patients with preservation of hearing in approximately 50%. Pituitary tumors with Cushing's syndrome, acromegaly, Nelson's syndrome, prolactinomas and non-secreting adenomas have been treated. Only a small subgroup of patients with low-grade gliomas are candidates for interstitial radiosurgery, namely those with circumscribed tumors with limited spread of tumor cells into the periphery. For this subgroup, which usually comprises not more than 25% of all low-grade gliomas, interstitial radiosurgery competes with surgical resection. Local, single high-dose treatment remains controversial for highly malignant infiltrative tumors, and a significant treatment benefit remains to be demonstrated. Radiosurgery can be used to effectively treat solitary brain metastases (< or = 3 cm diameters) with less invasiveness, and dissection of normal tissue; it may be performed with lower morbidity and with less expense in comparison with open surgery.
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PMID:[Stereotaxic radiosurgery]. 780 64

Adrenalectomy is a radical therapeutic approach to control hypercortisolism in some patients with Cushing's disease. However it may be complicated by the Nelson's syndrome, defined by the association of a pituitary macroadenoma and high ACTH secretion after adrenalectomy. This definition has not changed since the end of the fifties. Today the Nelson's syndrome must be revisited with new to criteria using more sensitive diagnostic tools, especially the pituitary magnetic resonance imaging. In this paper we will review the pathophysiological aspects of corticotroph tumor growth, with reference to the impact of adrenalectomy. The main epidemiological data on the Nelson's syndrome will be presented. More importantly, we will propose a new pathophysiological and practical approach to this question which attempts to evaluate the Corticotroph Tumor Progression after adrenalectomy, rather than to diagnose the Nelson's syndrome. We will discuss the consequences for the management of Cushing's disease patients after adrenalectomy, and will also draw some perspectives.
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PMID:The Nelson's syndrome... revisited. 1613 3

Nelson's syndrome was defined in 1958 as the association of an expanding pituitary tumor with high ACTH secretion after bilateral adrenalectomy for Cushing's disease. Pituitary MRI and ACTH measurements led to the definition of Nelson's syndrome as the proliferation of a corticotrophic microadenoma or an aggressive and highly proliferative tumor residue induced by the decreased glucocorticoid inhibition after bilateral adrenalectomy. Now, the problem is not the definition of Nelson's syndrome but rather the identification of markers predictive of tumor growth. Based on a typical case and a review of the literature, we point out some predictive markers of tumor growth after bilateral adrenalectomy: young age at diagnosis, presence of tumor residue on pituitary MRI before adrenalectomy, markers of tumor aggressiveness (Ki-67>3%, mitoses, nuclear PTTG) and increase of ACTH levels during the first months following adrenalectomy.
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PMID:[Nelson's syndrome: course of aggressive pituitary corticotroph adenoma]. 1730 8

OBJECTIVE Nelson-Salassa syndrome (NSS) is a rare consequence of bilateral adrenalectomy (ADX) for refractory hypercortisolism due to Cushing disease (CD). Although classically defined by rapid growth of a large, invasive, adrenocorticotropin hormone (ACTH)-secreting pituitary tumor after bilateral ADX that causes cutaneous hyperpigmentation, visual disturbance, and high levels of ACTH, clinical experience suggests more variability. METHODS The authors conducted a retrospective chart review of all patients 18 years and older with a history of bilateral ADX for CD, adequate pituitary MRI, and at least 2 years of clinical follow-up. Statistical tests included Student's t-test, chi-square test, Fisher's exact test, multivariate analysis, and derived receiver operating characteristic curves. RESULTS Between 1956 and 2015, 302 patients underwent bilateral ADX for the treatment of hypercortisolism caused by CD; 88 had requisite imaging and follow-up (mean 16 years). Forty-seven patients (53%) had radiographic progression of pituitary disease and were diagnosed with NSS. Compared with patients who did not experience progression, those who developed NSS were significantly younger at the time of CD diagnosis (33 vs 44 years, p = 0.007) and at the time of bilateral ADX (35 vs 49 years, p = 0.007), had larger tumors at the time of CD diagnosis (6 mm vs 1 mm, p = 0.03), and were more likely to have undergone external-beam radiation therapy (EBRT, 43% vs 12%, p = 0.005). Among NSS patients, the mean tumor growth was 7 mm/yr (SE 6 mm/yr); the median tumor growth was 3 mm/yr. Prevalence of pathognomonic symptoms was low; the classic triad occurred in 9%, while hyperpigmentation without visual field deficit was observed in 23%, and 68% remained asymptomatic despite radiographic disease progression. NSS required treatment in 14 patients (30%). CONCLUSIONS NSS is a prevalent sequela of CD after bilateral ADX and affects more than 50% of patients. However, although radiological evidence of NSS is common, it is most often clinically indolent, with only a small minority of patients developing the more aggressive disease phenotype characterized by clinically meaningful symptoms and indications for treatment. Young age at the time of CD diagnosis or treatment with bilateral ADX, large tumor size at CD diagnosis, and EBRT are associated with progression to NSS and may be markers of aggressiveness.
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PMID:Characterizing and predicting the Nelson-Salassa syndrome. 2808 14

Nelson's syndrome is a rare condition defined by enlargement of a pituitary adenoma following bilateral adrenalectomy for treatment of Cushing disease. Nelson's syndrome occurs at an incidence of 8-38% and is more frequent in younger people. This syndrome is characterized by skin hyperpigmentation and very high circulating levels of adrenocorticotrophic hormone. The pathophysiology of the disease is still not fully understood, and it is unknown what factors drive corticotroph cells in these patients. Presently, the syndrome is diagnosed at earlier stages and therefore its clinical manifestation is less typical than in the past. However, we can still find cases of full-blown Nelson's syndrome, resulting from massive tumor growth and dramatically increased production of adrenocorticotrophic hormone. Treatment of this syndrome largely consists of surgery and/or radiotherapy because of the limited effectiveness of pharmacotherapy. Although no guidelines have been published, it is reasonable to perform pituitary imaging and to assess adrenocorticotrophic hormone in all patients, particularly during the first years after bilateral adrenalectomy. The purpose of this paper is to review the current views on the etiopathogenesis, clinical presentation, diagnosis and treatment of Nelson's syndrome.
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PMID:[Nelson's Syndrome]. 2850 41

Nelson's syndrome (NS) is a condition which may develop in patients with Cushing's disease after bilateral adrenalectomy. Although there is no formal consensus on what defines NS, corticotroph tumor growth and/or gradually increasing ACTH levels are important diagnostic elements. Pathogenesis is unclear and well-established predictive factors are lacking; high ACTH during the first year after bilateral adrenalectomy is the most consistently reported predictive parameter. Management is individualized and includes surgery, with or without radiotherapy, radiotherapy alone, and observation; medical treatments have shown inconsistent results. A subset of tumors demonstrates aggressive behavior with challenging management, malignant transformation and poor prognosis.
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PMID:Nelson's Syndrome: An Update. 3274 80


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