pituitary tumors

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor best known for its ability to mediate the effects of environmental toxins such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin), polycyclic aromatic hydrocarbons (PAHs), benzene, and polychlorinated biphenyls (PCBs) through the initiation of transcription of a number of metabolically active enzymes. Therefore, the AHR has been studied mostly in the context of xenobiotic signaling. However, several studies have shown that the AHR is constitutively active and plays an important role in general cell physiology, independently of its activity as a xenobiotic receptor and in the absence of exogenous ligands...

OBJECTIVE: Data regarding pregnancies in relation to pituitary tumors are limited. The effects of pregnancy on pituitary adenomas and the effects of adenoma itself (hormonal activity, mass effects and pituitary insufficiency) and/or treatment on the ongoing gestation and developing fetus were evaluated. METHODS: The study was a retrospective study. A questionnaire involving questions regarding medical history before index gestation, history of related pregnancy, result of index gestation and postpartum follow-up of the patients was filled by the investigator in one of the eight Referral Endocrinology Centers from Turkey...

Spindle cell oncocytoma (SCO) of adenohypophysis was first described in 2002 by Roncaroli et al. as a new entity in the tumors originating from adenohypophysis. It was subsequently recognized as a distinct entity in the 2007 WHO classification of CNS tumors and retained in the current updated classification. In contrast to that suggested by the original authors, this tumor does have a potential for recurrence as first described by Kloub et al. and later with many such case reports. This tumor can be confused with other sellar tumors like pituicytomas and pituitary adenoma, both radiologically and histopathologically...

The incidence of brain tumors in the elderly population has increased over the last few decades. Current treatment includes surgery, radiotherapy and chemotherapy, but the optimal management of older patients with brain tumors remains a matter of debate, since aggressive radiation treatments in this population may be associated with high risks of neurological toxicity and deterioration of quality of life. For such patients, a careful clinical status assessment is mandatory both for clinical decision making and for designing randomized trials to adequately evaluate the optimal combination of radiotherapy and chemotherapy...

Magnetic resonance imaging (MRI) is the modality of choice as far as imaging diagnosis of pathologies in the pituitary gland is concerned. Further, the advent of dynamic contrast enhanced (DCE) has enhanced the capability of this modality in detecting minute benign but endocrinologically significant tumors called microadenoma. These lesions are visible with difficulty and a low confidence level in routine MRI sequences, even after administration of intravenous gadolinium. Techniques to enhance the visualization of such foci would be an asset in improving the overall accuracy of DCE-MRI for detection of pituitary microadenomas...

PTEN hamartoma tumor syndrome (PHTS), DICER1 syndrome, and hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome are pleiotropic tumor predisposition syndromes that include benign and malignant neoplasms affecting adults and children. PHTS includes several disorders with shared and distinct clinical features. These are associated with elevated lifetime risk of breast, thyroid, endometrial, colorectal, and renal cancers as well as melanoma. Thyroid cancer represents the predominant cancer risk under age 20 years...

In animal models, estrogens are complete carcinogens in certain target sites. 4-Hydroxyestradiol (4-OH-E2), an endogenous metabolite of 17β-estradiol (E2), is known to have prominent estrogenic activity plus potential genotoxicity and mutagenicity. We report here our finding that 4-OH-E2 does not induce pituitary tumors in ACI female rats, whereas E2 produces 100% pituitary tumor incidence. To probe the mechanism, we conducted a short-term animal experiment to compare the proliferative effect of 4-OH-E2 in several organs...

The pituitary gland plays a pivotal role in the endocrine system, steering fundamental processes of growth, metabolism, reproduction and coping with stress. The adult pituitary contains resident stem cells which are highly quiescent in homeostatic conditions. However, the cells show marked signs of activation during processes of increased cell remodeling in the gland, including maturation at neonatal age, adaptation to physiological demands, regeneration upon injury, and growth of local tumors. Although functions of pituitary stem cells are slowly but gradually uncovered, their regulation largely remains virgin territory...

Cushing syndrome (CS) is caused by chronic exposure to excess glucocorticoids. Early recognition and treatment of hypercortisolemia can lead to decreased morbidity and mortality. The diagnosis of CS and thereafter, establishing the cause can often be difficult, especially in patients with mild and cyclic hypercortisolism. Surgical excision of the cause of excess glucocorticoids is the optimal treatment for CS. Medical therapy (steroidogenesis inhibitors, medications that decrease adrenocorticotropic hormone [ACTH] levels or glucocorticoid antagonists) and pituitary radiotherapy may be needed as adjunctive treatment modalities in patients with residual, recurrent or metastatic disease, in preparation for surgery, or when surgery is contraindicated...

OBJECTIVE: Ectopic ACTH secretion is a less common cause of Cushing's syndrome, and is seen in 5 to 10% of cases with endogenous hypercortisolemia. We hereby describe our experience of patients with ectopic ACTH syndrome, who have been managed over the past 10 years at a tertiary care centre in Southern India. METHODS: The inpatient and outpatient records of patients from 2006 to 2015 were retrospectively reviewed. The clinical features, clinical history, biochemical values, imaging features which included radiological findings and PET scans, management, details of follow-up and outcomes were documented...

OBJECTIVES: Cushing's disease (CD) results from excessive exposure to glucocorticoids caused by an adrenocorticotropic hormone-secreting pituitary tumor. Inadequately-treated CD is associated with significant morbidity and elevated mortality. Multi-center data on CD patients treated in routine clinical practice are needed to assess treatment outcomes in this rare disorder. The study purpose was to describe the burden of illness and treatment outcomes for CD patients. METHODS: Eight pituitary centers in 4 US regions participated in this multi-center retrospective chart review study...

Dopamine agonists such as bromocriptine and cabergoline have been successfully used in the treatment of pituitary prolactinomas and other neuroendocrine tumors. However, their therapeutic mechanisms are not fully understood. In this study we demonstrated that DRD5 (dopamine receptor D5) agonists were potent inhibitors of pituitary tumor growth. We further found that DRD5 activation increased production of reactive oxygen species (ROS), inhibited the MTOR pathway, induced macroautophagy/autophagy, and led to autophagic cell death (ACD) in vitro and in vivo...

Treatment of aggressive pituitary tumors may be challenging. Temozolomide (TMZ) is a promising agent when conventional treatment methods fail. We present three patients with aggressive pituitary tumors with atypical morphology, who were resistant to conventional treatments and treated with TMZ. First case had a somatotroph adenoma, second a corticotroph adenoma, and the third a macroprolactinoma. We also reviewed the literature reporting TMZ efficacy in somatotroph, corticotroph and mammotroph tumors of pituitary...

The association between nephrolithiasis and acromegaly has been previously described. Although the mechanism has been established, the urological literature sparsely discusses clinically suspecting that patients with recurrent nephrolithiasis could have acromegaly and subsequently referring them for accurate diagnosis and treatment. We present a case of occult acromegaly secondary to a pituitary tumor discovered 20 years after the patient's first stone episode.

Background  Parasellar invasion of pituitary adenomas (PAs) into the cavernous sinus (CS) is common. The management of the CS component of PA remains controversial. Objective  The objective of this study was to analyze CS involvement in PA treated with endoscopic endonasal approaches, including incidence, surgical risks, surgical strategies, long-term outcomes, and our treatment algorithm. Methods  We reviewed a series of 176 surgically treated PA with particular attention to CS involvement and whether the CS tumor was approached medial or lateral to the internal carotid artery...

OBJECTIVE: This study aimed to determine the predictive factors for endocrinological remission of patients with growth hormone (GH)-secreting pituitary adenomas. METHODS: In 47 patients with GH-secreting pituitary adenomas who underwent endoscopic endonasal transsphenoidal surgery with intraoperative GH measurements from 2002 to 2011, the relationship between the intraoperative GH levels and postoperative remission was analyzed, and two items that predicted remission (GH half-life obtained 30 min or less after removal and a minimum surgical GH level less than 2...

Predicting aggressive or malignant behavior of pituitary adenomas (PAs) remains challenging. Aberrant expression of cyclin B1 (CCNB1) occurred in various tumors including PAs. Our study was aimed to explore its roles in the development of PAs aggressiveness. According to the integrated analysis, the expression of CCNB1 was evaluated. Following bioinformatics analysis was performed to uncover the pathways CCNB1 involved in and the upstream transcriptional regulation factors. The mRNA expression of CCNB1 was verified by qRT-PCR...

Pituitary adenoma (PA) is a common type of benign tumor of the pituitary gland that is characterized by specific signs and symptoms, primarily associated with hypersecretion of pituitary glycoprotein hormones (thyroid-stimulating, growth and adrenocorticotrophic hormones, and prolactin). Surgery is the first-line treatment, although postoperative residual tissues/cells and subsequent recurrence remain notable complications. Gene therapy is an effective approach for treatment, as previous studies have demonstrated that the Notch signaling pathway participates in the pathogenesis of PA...

OBJECTIVE In 2004, the WHO classified atypical pituitary adenoma as a distinct adenoma subtype. However, the clinical significance of this distinction remains undetermined. The authors sought to define patient characteristics, tumor features, and treatment outcomes associated with atypical pituitary adenoma. METHODS The authors reviewed records of patients who underwent resection of pituitary adenoma at the University of California, San Francisco, between 2007 and 2014. Per institutional protocol, adenomas exhibiting mitotic activity underwent evaluation for all 3 markers of atypicality (mitotic index, extensive p53 staining, and MIB-1 index ≥ 3%)...

Object  Endoscopic transsphenoidal surgery is the commonest approach to pituitary tumors. One disadvantage of this approach is the development of early postoperative nasal symptoms. Our aim was to clarify the peak onset of these symptoms and their temporal evolution. Methods  The General Nasal Patient Inventory (GNPI) was administered to 56 patients undergoing endoscopic transsphenoidal surgery for pituitary tumors preoperatively and at 1 day, 3 days, 2 weeks, 3 months, and 6 to 12 months postoperatively...