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Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options., Graphical Abstract Graphical Abstract

ContextCraniopharyngiomas, which are categorized as adamantinomatous (ACPs) or papillary (PCPs), have traditionally been treated with surgery and/or radiotherapy, although when the tumors progress or recur, therapeutic possibilities are very limited. Following recent advances in their molecular pathogenesis, new medical therapeutic options have emerged.Evidence AcquisitionThe search strategy that we selected to identify the appropriate evidence involved the following medical subject headings (MeSH) terms: (“Craniopharyngioma” [MeSH] AND “Craniopharyngioma/drug therapy” [MeSH]) NOT (“review” [Publication Type] OR “review literature as topic” [MeSH Terms] OR “review” [All Fields]) AND (“2009/05/01” [PDat]: “2019/04/28” [PDat]).Evidence SynthesisMutations of β-catenin causing Wnt activation with alterations of the MEK/ERK pathway are encountered in the great majority of patients with ACPs; specific alterations also stratify patients to a more aggressive behavior. In most PCPs there is primary activation of the Ras/Raf/MEK/ERK pathway secondary to BRAF-V600E mutations. BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCPs producing clinically useful and, in some cases, sustained responses. In contrast to PCPs, drugs targeting β-catenin and its downstream MAPK pathway in ACPs have so far only been used in in vitro studies, but there appear to be promising new targets clinically.ConclusionsThe identification of specific genetic alterations in patients with craniopharyngiomas has expanded the therapeutic options, providing evidence for a customized approach using newer molecular agents. More studies including a larger number of carefully selected patients are required to evaluate the response to currently available and evolving agents alone and in combination.

Context Although most sellar lesions are related to pituitary adenomas, the region gives rise to a variety of neoplasms that can be associated with substantial morbidity and/or mortality. Design Information from reviews and guidelines of relevant societies dealing with such neoplasms, as well as articles that have provided new developments that made important contributions to their pathogenesis and treatment up to 2018, were obtained: public indexes such as PubMed/MEDLINE were used with the relevant search items. Results Sellar neoplasms have a worse outcome than pituitary adenomas that is related not only to their natural history but also to side effects of therapies and evolving endocrine and/or hypothalamic deficiencies. Recent imaging advances have established the radiological fingerprint of some of these neoplasms, and several chromosomal aberrations have also been identified. Although established approaches along with new surgical and radiotherapeutic approaches remain the main treatment modalities, recent evidence has provided insight into their molecular pathogenesis involving, other than chemotherapy, treatments with targeted agents as in gliomas and craniopharyngiomas bearing BRAF mutations. Development of predictive markers of recurrences may also identify high-risk patients, including proliferative markers and expression of the progesterone receptor in meningiomas, and lead to less aggressive surgery. Owing to the rarity and complexity of these neoplasms, patients should be managed in dedicated centers. Conclusions The diagnosis and management of sellar neoplasms necessitate a multidisciplinary approach. Following evolving recent advances in their diagnosis and therapy, such a multidisciplinary approach needs to be extended to establish evidence-based diagnostic and management plans.

Langerhans Cell Histiocytosis (LCH) is a rare disease exhibiting both neoplastic and inflammatory features including abundant cytokine secretion both at the lesional and systemic level.Evaluation of RANKL expression within LCH lesions in various tissues.Cross-sectional study involving paraffin blocks from the diagnostic biopsies of adults with LCH.The study was conducted among patients followed in an adult outpatient clinic.Eleven patients with active LCH, who were 41.27 ± 3.44 years old, and five patients who were 46.8 ± 7.19 years old with non-LCH diagnosis serving as controls.RANKL, p65 and CD1a immunostaining of deparaffinized sections from LCH lesions and control tissues.Comparison of RANKL and p65 expression between LCH lesions, as indicated from concomitant CD1a immunostaining, and control tissue counterparts.A focal positive granular cytoplasmic RANKL staining was found at all lesional sites in a number of cells of the pathological infiltrate, mostly with morphologic features of pathological Langerhans cells (LCs). Compared to control tissues, RANKL positivity in LCH cases showed an excess of staining, both in intensity of staining and the number of stained cells, especially in areas of pathologic infiltration. RANKL staining also coincided with strong p65 NFκB nuclear positivity, especially in lesional infiltrates.RANKL is highly expressed in active LCH at the lesional level, concomitant to p65 NFκB activation. The use of RANKL inhibition as a rational therapeutic approach of the disease now needs further clinical evaluation.

Context: Although adrenal incidentalomas (AIs) are associated with a high prevalence of cardiovascular risk (CVR) factors, it is not clear whether patients with nonfunctioning AI (NFAI) have increased CVR. Objective: Our objective was to investigate CVR in patients with NFAI. Design and Setting: This case-control study was performed in a tertiary general hospital. Subjects: Subjects included 60 normotensive euglycemic patients with AI and 32 healthy controls (C) with normal adrenal imaging. Main Outcome Measures: All participants underwent adrenal imaging, biochemical and hormonal evaluation, and the following investigations: 1) measurement of carotid intima-media thickness (IMT) and flow-mediated dilatation, 2) 2-hour 75-gram oral glucose tolerance test and calculation of insulin resistance indices (homeostasis model assessment, quantitative insulin sensitivity check, and Matsuda indices), 3) iv ACTH stimulation test, 4) low-dose dexamethasone suppression test, and 5) NaCl (0.9%) post-dexamethasone saline infusion test. Results: Based on cutoffs obtained from controls, autonomous cortisol secretion was documented in 26 patients (cortisol-secreting AI [CSAI] group), whereas 34 exhibited adequate cortisol and aldosterone suppression (NFAI group). IMT measurements were higher and flow-mediated vasodilatation was lower in the CSAI group compared with both NFAI and C and in the NFAI group compared with C. The homeostasis model assessment index was higher and quantitative insulin sensitivity check index and Matsuda indices were lower in the CSAI and NFAI groups compared with C as well as in CSAI compared with the NFAI group. The area under the curve for cortisol after ACTH stimulation was higher in the CSAI group compared with the NFAI group and C and in the NFAI group compared with C. In the CSAI group, IMT correlated with cortisol, urinary free cortisol, and cortisol after a low-dose dexamethasone suppression test, whereas in the NFAI group, IMT correlated with area under the curve for cortisol after ACTH stimulation and urinary free cortisol. Conclusions: Patients with CSAI without hypertension, diabetes, and/or dyslipidemia exhibit adverse metabolic and CVR factors. In addition, NFAIs are apparently associated with increased insulin resistance and endothelial dysfunction that correlate with subtle but not autonomous cortisol excess.

Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology with a strong evidence of immunological dysfunction secondary to cytokine dysregulation.This study aimed to evaluate serum receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and Dickkopf-1 (Dkk-1) levels in adult patients with LCH at various stages of the disease.This was a cross-sectional study in an adult LCH cohort followed for 12.2 ± 2.1 yr.The study was conducted in an outpatient clinic.Twenty-five adult patients with a definitive LCH diagnosis and 50 matched controls participated in the study.Early morning, fasting, venous sampling was conducted in all subjects.We compared RANKL, OPG, and Dkk-1 serum levels between patients and controls, as well as their association with disease parameters.Serum OPG levels were significantly higher (3.0 ± 0.2 vs. 1.7 ± 0.1 pmol/liter; P0.001), whereas RANKL/OPG ratio was significantly lower (0.201 ± 0.041 vs. 0.471 ± 0.072; P = 0.02) in LCH patients compared to controls. Both higher OPG (adjusted odds ratio, 3.431; 95% confidence interval, 1.329-8.924) and lower RANKL (adjusted odds ratio, 0.144; 95% confidence interval, 0.034-0.605) levels were independently associated with LCH in logistic regression analysis, after adjustment for all other parameters. Dkk-1 did not differ among patients and controls.Adults with LCH have high serum OPG levels and low serum RANKL levels. In contrast with other disorders involving the skeleton, serum Dkk-1 levels are similar between LCH patients and controls.

Data from previous retrospective studies and case reports have suggested that infectious diseases of the central nervous system could cause pituitary deficiency.The aim of this prospective study was to investigate pituitary function in patients admitted with infectious meningitis during the acute phase and after 12 months.Sixteen patients were studied. Basal pituitary function was assessed within 24 h of admission. Twelve of these patients underwent both basal and stimulated (insulin tolerance test) pituitary testing after 12 months.During the acute phase, five patients (31.25%) showed apparent pituitary hormone deficiencies: two patients with gonadotropic and three patients with somatotropic deficiency. The exact status of corticosteroid sufficiency could not be defined in four patients, because no dynamic test was performed in the acute phase. In addition, seven patients (44%) had probable low T(3) syndrome. At 12 months, five patients (31.25%), two with viral and three with bacterial meningitis, had at least one anterior pituitary hormone deficiency. Two patients had isolated corticotropic and one isolated somatotropic deficiency. Combined corticotropic and somatotropic deficiencies were detected in two patients. New-onset deficiencies accounted for four of those five patients, whereas one patient demonstrated persisting somatotropic deficiency. All cases of low T(3) syndrome resolved at 12 months.Isolated or combined pituitary deficiencies, which could present at the acute phase and/or occur at a later stage, can develop in a considerable proportion of patients after acute infectious meningitis.

Pituitary carcinomas are rare, making up some 0.2% of all pituitary tumors, but represent a particular challenge to clinical practice. The diagnosis of a pituitary carcinoma requires evidence of metastatic disease, either outside the central nervous system (CNS) or as separate noncontiguous foci within the CNS. They may present as typical pituitary adenomas, which reveal their malignant character only as time progresses, or as peculiarly aggressive tumors ab initio. Recent changes in histopathological classification have clarified many of the features of such tumors, including immunohistochemical staining for Ki-67 and p53, but to date none has been found to be pathognomonic. The majority of carcinomas are secretory, usually arising from corticotroph tumors or prolactinomas, but all histological types and secretory patterns are represented. Treatment is by surgery, transsphenoidal wherever possible, and conventional and stereotactic radiotherapy, but ultimately, a plethora of therapies may be required, including various attempts at medical therapy. Chemotherapy in some instances probably prolongs survival, but, in general, their progress from the diagnosis of carcinomatous changes is progressive and inexorable. However, we do not believe there will be any real prospect of long-term survival until the development and use of therapies targeted at specific molecular abnormalities.

Endocrine pancreatic tumors are rare neoplasms consisting of multipotent cells capable of secreting various bioactive substances causing characteristic clinical syndromes. Ovarian stromal hyperthecosis is characterized by varying degrees of luteinized stromal cell proliferation after sustained LH and/or human chorionic gonadotropin stimulation, clinically manifested by symptoms/signs of virilization resembling the polycystic ovary syndrome (PCOS). We report a case of ectopic bioactive LH production from a pancreatic endocrine tumor in a 33-yr-old woman with rapidly developing symptoms/signs of hyperandrogenism and markedly elevated serum androgen and LH levels leading to hyperthecosis and bilateral luteinized granulosa-thecal cell tumors of the ovaries. Although the patient was initially thought to have either severe PCOS or an LH-secreting pituitary tumor, an LH-producing pancreatic endocrine tumor bearing somatostatin receptors was demonstrated on scintigraphy with [111In]octreotide and abdominal imaging. Symptoms and signs of hyperandrogenism resolved after the resection of the tumor. Immunohistochemistry, in situ hybridization, and electron microscopy studies confirmed LH synthesis by the tumor cell. Although extremely rare, ectopic LH production from nonpituitary endocrine tumors should be considered in the differential diagnosis of hyperandrogenism, particularly when associated with highly elevated serum LH levels.

We studied 211 hyperandrogenic women with respect to clinical presentation, basal androgen levels, and the degree of cortisol and androgen suppression during a 48-h low-dose (2 mg) dexamethasone-suppression test (LDDST) to exclude ovarian and adrenal tumors. In 42 women with elevated testosterone levels, 21 of whom failed to suppress testosterone during the LDDST, the response of serum androgen levels during a 4-wk administration of 7.5 mg prednisolone in a reverse circadian regimen was also assessed. These results were compared with an additional 17 patients with histologically proven androgen-secreting tumors. Clinical presentation alone was suggestive of a virilizing tumor in 70% of patients with tumors. Serum testosterone, although occasionally only marginally elevated, was the sole androgen that was elevated in every patient with a tumor. After the LDDST, none of the patients with tumors obtained either a greater than 40% reduction or normalization of the previously elevated testosterone levels, whereas 88% of patients with nontumorous hyperandrogenism showed either normalization or suppression of more than 40%. With one exception, all of the patients with nontumorous hyperandrogenism who showed inadequate suppression of testosterone during the LDDST, and were treated with prednisolone, normalized the previously elevated androgens after 1 month of administration. In summary, in women presenting with hyperandrogenism, lack of testosterone suppression during the LDDST is associated with 100% sensitivity and 88% specificity in distinguishing patients with ovarian and adrenal androgen-secreting tumors from patients with nontumorous hyperandrogenism in this small series. The LDDST is an easy to perform screening test that can also identify causes of hyperandrogenism due to altered glucocorticoid secretion.

Macrophage migration inhibitory factor (MIF) is a proinflammatory pituitary and immune cell cytokine and a critical mediator of septic shock. It has been reported that MIF is secreted in parallel with ACTH from the pituitary in response to stress or inflammatory stimuli. MIF release from immune cells is also induced rather than inhibited by glucocorticoids. It has therefore been suggested that MIF may be a novel counterregulatory hormone of glucocorticoid action that acts both as a paracrine and endocrine modulator of host responses. We have measured circulating MIF levels, using a human MIF ELISA, in normal subjects and patients under numerous pathophysiological conditions. Serum MIF was measured in normal subjects who underwent stimulation of the hypothalamo-pituitary-adrenal axis with an insulin tolerance test (n 8), a CRH-stimulation test (n 5), a short synacthen test (n 5), and following a low-dose dexamethasone suppression test (n 6). We also sampled from a peripheral vein and both inferior petrosal sinuses before and after CRH stimulation in four patients with a histologically proven diagnosis of Cushing’s disease. Immunostaining of the pituitary tumors for MIF was also performed. In normal subjects serum MIF levels did not rise in parallel with cortisol during the insulin tolerance or CRH test or after administration of synthetic ACTH. In all subjects cortisol levels became undetectable after the lowdose dexamethasone suppression test, and no consistent change was observed in serum MIF levels during the test. In patients with Cushing’s disease, there was no basal centralto-peripheral gradient in MIF, and no consistent changes occurred in serum MIF levels in either the left or right inferior petrosal sinus after CRH stimulation; however, immunostaining of the surgically removed pituitary tumors from the same patients showed strong staining for both ACTH and MIF. These results show that in humans acute modulation of the hypothalamo-pituitary-adrenal axis does not significantly alter circulating MIF levels. In addition, ACTH-secreting pituitary tumors that express MIF do not release MIF either spontaneously or in response to CRH stimulation, and there is no gradient for MIF in the venous drainage of the pituitary. Our study suggests that the pituitary gland is not the major contributor to circulating MIF; an autocrine or paracrine role for pituitary-derived MIF is more likely. (J Clin Endocrinol Metab 87: 1834 –1840, 2002)

A 37-yr-old woman with clinical, endocrinological, and radiological features suggestive of a nonfunctioning pituitary tumor was found to have a chondrosarcoma of the pituitary sella. The bony structures around the sella were relatively uninvolved, other than showing minor erosion of the left side of the dorsum and the posterior wall of the sphenoid sinus. After partial resection of the tumor by the transsphenoidal route the patient received postoperative radiosurgery by a linear accelerator, stereotactic multiarc radiotherapy. Subsequent follow-up revealed reduction of the residual tumor. This case demonstrates that a chondrosarcoma may apparently arise directly from the pituitary fossa and suggests the efficacy of stereotactic radiosurgery, at least in the medium term. The origin, areas of involvement, management, and long-term prognosis of these rare tumors are reviewed.

The interconversion of hormonally active cortisol (F) and inactive cortisone (E) is catalyzed by two isozymes of 11β-hydroxysteroid dehydrogenase (11βHSD), an oxo-reductase converting E to F (11βHSD1) and a dehydrogenase (11βHSD2) converting F to E. 11βHSD1 is important in mediating glucocorticoid-regulated glucose homeostasis and regional adipocyte differentiation. Earlier studies conducted with GH-deficient subjects treated with replacement GH suggested that GH may modulate 11βHSD1 activity.In 7 acromegalic subjects withdrawing from medical therapy (Sandostatin-LAR; 20–40 mg/month for at least 12 months), GH rose from 7.1 ± 1.5 to 17.5 ± 4.3 mU/L (mean ± se), and insulin-like growth factor I (IGF-I) rose from 43.0 ± 8.8 to 82.1 ± 13.7 nmol/L (both P < 0.05) 4 months after treatment. There was a significant alteration in the normal set-point of F to E interconversion toward E. The fall in the urinary tetrahydrocortisols/tetrahydocortisone ratio (THF+allo-THF/THE; 0.82 ± 0.06 to 0.60 ± 0.06; P < 0.02) but unaltered urinary free F/urinary free E ratio (a marker for 11βHSD2 activity) suggested that this was due to inhibition of 11βHSD1 activity. An inverse correlation between GH and the THF+allo-THF/THE ratio was observed (r = −0.422; P < 0.05). Conversely, in 12 acromegalic patients treated by transsphenoidal surgery (GH falling from 124 ± 49.2 to 29.3 ± 15.4 mU/L; P < 0.01), the THF+allo-THF/THE ratio rose from 0.53 ± 0.06 to 0.63 ± 0.07 (P < 0.05). Patients from either group who failed to demonstrate a change in GH levels showed no change in the THF+allo-THF/THE ratio.In vitro studies conducted on cells stably transfected with either the human 11βHSD1 or 11βHSD2 complementary DNA and primary cultures of human omental adipose stromal cells expressing only the 11βHSD1 isozyme indicated a dose-dependent inhibition of 11βHSD1 oxo-reductase activity with IGF-I, but not GH. Neither IGF-I nor GH had any effect on 11βHSD2 activity.GH, through an IGF-I-mediated effect, inhibits 11βHSD1 activity. This reduction in E to F conversion will increase the MCR of F, and care should be taken to monitor the adequacy of function of the hypothalamo-pituitary-adrenal axis in acromegalic subjects and in GH-deficient, hypopituitary patients commencing replacement GH therapy. Conversely, enhanced E to F conversion occurs with a reduction in GH levels; in liver and adipose tissue this would result in increased hepatic glucose output and visceral adiposity, suggesting that part of the phenotype currently attributable to adult GH deficiency may be an indirect consequence of its effect on tissue F metabolism via 11βHSD1 expression.

GH secretagogues (GHSs) act via specific receptors in the hypothalamus and the pituitary gland to release GH. GHSs also stimulate the hypothalamo-pituitary-adrenal (HPA) axis via central mechanisms probably involving CRH or arginine vasopressin (AVP). We studied the effects of hexarelin, CRH, and desmopressin, an AVP analog, on the stimulation of the HPA axis in 15 healthy young male volunteers. Circulating ACTH, cortisol, GH and PRL concentrations were measured for 2 h after the injection of hexarelin, CRH, or desmopressin alone and the combination of hexarelin plus CRH or hexarelin plus desmopressin. Symptoms during the tests were assessed by visual analog scales. Hexarelin significantly increased ACTH and cortisol release (area under the curve, 3,444+/-696 ng/L x 125 min and 45,844+/-2,925 nmol/L x 125 min, respectively), and this effect was augmented by the addition of CRH in a dose that on its own produces maximal stimulation (6,580+/-1,572 ng/mL x 125 min and 63,170+/-2,616 nmol/L x 125 min; P = 0.01 and 0.001, respectively), but was not influenced by the addition of desmopressin (3,540+/-852 ng/mL x 125 min and 35,319+/-3,252 nmol/L x 125 min; not significant). CRH on its own caused similar or slightly higher ACTH and cortisol release than hexarelin alone. Desmopressin given alone elicited a rapid rise in circulating ACTH and cortisol, but its effects were less than those of any other treatment and were not augmented by hexarelin. Hexarelin also caused significant GH and PRL release, but these effects were not influenced by the coadministration of CRH or desmopressin. Visual analog scales showed an acute small increment in appetite with hexarelin. Our data suggest that the effect of GHSs on the HPA axis involve at least in part the stimulation of AVP release. In summary, we have shown that in healthy male volunteers, the effect of hexarelin on the HPA axis does not involve CRH, but may occur through the stimulation of AVP release.

Rathke's cleft cysts are cystic sellar and suprasellar lesions, characteristically lined by a single layer of ciliated cuboidal or columnar epithelium. In contrast, craniopharyngiomass, which are also cystic sellar and suprasellar lesions, are characteristically lined by stratified squamous epithelium with keratinization on a layer of connective tissue. The usual management recommended for Rathke's cleft cysts is simple surgical drainage with partial excision of the cyst wall. Recurrences of these cysts reportedly have been very rare. This retrospective study presents the details of 12 patients (6 females; median age 30 yr, range 21-58 yr) with Rathke's cleft cyst, referred to our department over a 15-yr period (1981-1996), an unusual feature being the recurrence of 4 (33%) of these lesions. Clinical, endocrine, radiological, surgical (10 transsphenoidal; 2 transcranial), and pathological details were recorded. Nine out of 12 patients (75%) were symptomatic; visual symptoms were the commonest, and 8 had visual field defects. The median duration of symptoms was 12 months (range 3-24 months). Three patients (25%) had panhypopituitarism, 2 of whom also had diabetes insipidus (17%). The cysts varied in size from 6 mm to 50 mm, 1 being entirely suprasellar. There were no pathognomonic clinical or radiological features to differentiate them from other pituitary lesions, although the presence of diabetes insipidus in 2 patients suggested that the lesion was not a pituitary adenoma. A definite histological diagnosis was possible in 8 patients; in 4, the diagnosis was presumptive. The median duration of follow-up was 30 months (1-168 months). Four patients (33%) showed reexpansion at 3, 6, 48, and 48 months after initial surgery, 3 of whom were symptomatic and required repeat surgery. Two of these patients were given postoperative external beam pituitary radiotherapy. Apparent recurrence of Rathke's cleft cysts after initially successful surgery in our series was higher than suggested by previous reports, and thus, long-term follow-up with pituitary imaging and neuroophthalmological assessment is essential. There are no specific characteristics of the cyst that predict recurrence. Ideal management of these cysts is unclear, but aspiration, followed by extensive excision of the cyst wall when possible, seems to be the best initial option. For recurrent symptomatic tumors, surgical resection is the treatment of choice. Considering the high recurrence rate with residual structural and functional dysfunction, the role of radiotherapy in preventing recurrence of these cysts needs careful evaluation with a larger study with a longer follow-up period.