Prolactinomas

Identifying prognostic predictors for postoperative pituitary neuroendocrine tumour recurrence: an integrated clinical, radiological, and immunohistochemistry assessment

OBJECTIVE

Pituitary neuroendocrine tumours (PitNETs) are the second most common type of intracranial tumour. Several studies have explored the prognostic factors for PitNETs. However, prognostic factors for postoperative PitNET recurrence remain not fully understood. This study aimed to explore potential prognostic factors for PitNET recurrence, such as surrounding tissue invasion and the extent of surgical resection in patients with postoperative PitNETs.

METHODS

We included 106 patients who underwent PitNET surgery between 2013 and 2018, dividing them into two groups: those with recurrence and those without recurrence. Tumours were classified based on demographics, neuroradiological, and immunohistological characteristics. Univariate and multivariate analyses were used to determine factors predicting recurrence. Kaplan-Meier plots and log-rank tests were used to analyse each independent factor based on the cumulative 5-year recurrence rate.

RESULTS

During the 5-year follow-up period, 29.2% of the patients (n = 31) had disease recurrence. Univariate analysis showed that predictors of recurrence included cavernous and sphenoid sinus invasions, optic chiasm compression, larger tumour volume, giant adenoma >4 cm, and gross total resection (GTR). Multivariate analysis showed that lactotroph tumour type, sphenoid sinus invasion, and GTR were independent predictors. Kaplan-Meier analysis revealed significant differences in the 5-year recurrence rate among the three independent predictors, with significantly lower recurrence rate in patients with lactotroph tumours and GTR, and a significantly higher recurrence risk in patients with sphenoid sinus invasion.

CONCLUSIONS

Lactotroph tumour type, sphenoid sinus invasion, and GTR are independent predictors of postoperative PitNET recurrence. This study provides insights into the factors affecting postoperative PitNET recurrence.

Long-term use of clomiphene in male macroprolactinomas with persistent hypogonadism

BACKGROUND

Men with macroprolactinoma can present persistent hypogonadism despite normoprolactinemia achieved with clinical and/or neurosurgical treatment. Usually, testosterone replacement therapy is indicated. Nevertheless, although off-label, clomiphene citrate (CC), a selective estrogen receptor modulator, has also been used, mainly when fertility is an issue. The aim of this study is to evaluate the effectiveness of CC in recovering the gonadal axis in men with macroprolactinoma, with or without hyperprolactinemia, and evaluate its safety as a long-term therapy.

METHODS

This is a retrospective study including 10 men with macroprolactinoma on cabergoline treatment and persistent hypogonadism. All patients received initially 50 mg/d of CC.

RESULTS

The median age at diagnosis of prolactinomas was 34 (range, 26-60) years old. All patients were treated with cabergoline at a median maximum dose of 2 (1-7) mg/week, with a median time of treatment of 8.5 (2-15) years. Prolactin was still above the normal range when CC was introduced only in two patients. The mean duration of CC therapy was 3.2 (±2.8) years. Prolactin levels maintained stable (p = 0.252) and testosterone increased (p = 0.027) significantly on CC therapy. Tumor size remained stable. Eight patients (80%) maintained testosterone above 300 ng/dL and were classified as responders. Three responders succeeded in using a lower dose of CC and one of them completed withdrawal CC and maintained eugonadism. There were no side effects or safety concerns reported.

CONCLUSION

CC should be seen as a safe treatment option for men with macroprolactinoma and persistent hypogonadism.

Treatment of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia. Treatment with these agents is effective in 80%-90% of the cases. Infertility treatment of patients with hyperprolactinemia is also carried out with dopamine agonists, aiming for the normalization of prolactin levels. The risk of symptomatic growth of prolactinomas during pregnancy is dependent on the tumor's size, duration of previous treatments, and prolactin levels. Notably, the corresponding risk is relatively low in cases of microprolactinomas (<5%). Remission of hyperprolactinemia occurs in about 30% of the patients after drug treatment and may also occur after pregnancy and menopause. The use of some drugs, such as antidepressants and antipsychotics, is a frequent cause of hyperprolactinemia, and managing this occurrence involves unique considerations. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and drug-induced hyperprolactinemia in women.

A study on the correlations of PRL levels with anxiety, depression, sleep, and self-efficacy in patients with prolactinoma

Purpose

The purpose of this study was to explore the factors influencing PRL levels in patients with prolactinoma and to investigate the correlations between anxiety, depression, sleep, self-efficacy, and PRL levels.

Methods

This retrospective study included 176 patients with prolactinoma who received outpatient treatment at the Affiliated Hospital of Zunyi Medical University from May 2017 to August 2022. The general information questionnaire, Hospital Anxiety and Depression Scale (HADS), Athens Insomnia Scale (AIS), and General Self-Efficacy Scale (GSES) were used for data collection. A generalized estimating equation (GEE) model was used to analyze the factors influencing PRL levels in patients with prolactinoma. GEE single-effect analysis was used to compare PRL levels at different time points between anxiety group and nonanxiety group, between insomnia group and normal group, and between low, medium, and high self-efficacy groups.

Results

The median baseline PRL level and the PRL levels at 1, 3, 6, and 12 months of follow-up were 268.50 ng/ml, 122.25 ng/ml, 21.20 ng/ml, 19.65 ng/ml, and 16.10 ng/ml, respectively. Among patients with prolactinoma, 59.10% had anxiety (HADS-A score = 7.35 ± 3.34) and 28.98% had depression (HADS-D score = 5.23 ± 3.87), 9.10% had sleep disorders (AIS score = 6.10 ± 4.31) and 54.55% had low self-efficacy (GSES score = 2.13 ± 0.83). Educational level, tumor size, number of visits, sleep quality, anxiety level, and self-efficacy level were found to be factors influencing PRL levels in patients with prolactinoma (P<0.05). Higher PRL levels were observed in the anxiety group compared to the non-anxiety group (P<0.001), in the insomnia group compared to the normal group (P<0.05), and in the low self-efficacy group compared to the medium and high self-efficacy groups (P<0.05).

Conclusion

PRL levels in patients with prolactinoma are related to education level, tumor size, number of visits, anxiety, self-efficacy, and sleep but not depression. PRL levels were higher in patients with anxiety, low self-efficacy, and sleep disorders.

PRL-R Variants Are Not Only Associated With Prolactinomas But Also With Dopamine Agonist Resistance

CONTEXT

Knockout prolactin receptor gene (PRL-R) mice are animal models for prolactinomas and PRL acts via autocrine/paracrine inhibiting lactotroph proliferation. Recently, variants of the PRL-R were identified in prolactinoma patients and their frequency was higher compared to individuals from the genomic database.

OBJECTIVE

We analyzed PRL-R variants frequency in an extensive cohort of prolactinoma patients and evaluated their association with clinical, laboratorial, and imaging characteristics and hormonal response to cabergoline.

DESIGN

Observational, retrospective, and cross-sectional study.

SETTING

This study took place at the Neuroendocrinology Unit of Clinics Hospital, Medical School of University of São Paulo, Brazil, a tertiary referral center.

PATIENTS AND METHODS

Study participants included adults with sporadic prolactinomas treated with cabergoline, where response to therapy was defined by prolactin normalization with up to 3 mg/week doses. DNA was extracted from blood samples and the PRL-R was analyzed by polymerase chain reaction techniques and automatic sequencing. The association of PRL-R variants with serum prolactin levels, maximal tumor diameter, tumor parasellar invasiveness, and response to cabergoline was analyzed.

RESULTS

We found 6 PRL-R variants: p.Ile100(76)Val, p.Ile170(146)Leu, p.Glu400(376)Gln/p.Asn516(492)Ile, p.Glu470Asp e p.Ala591Pro; the last 2 are newly described in prolactinomas' patients. The variants p.Glu400(376)Gln/p.Asn516(492)Ile and p.Ala591Pro were more frequent amongst patients compared to genomic databases, and the p.Asn516(492)Ile showed pathogenic potential using in silico analysis as previously described. PRL-R variants were associated with male sex (P = 0.015), higher serum PRL levels (P = 0.007), larger tumors (P = 0.001), and cabergoline resistance (P < 0.001).

CONCLUSIONS

The prolactin/prolactin receptor system seems to be related to prolactinoma tumorigenesis and cabergoline resistance. Additional studies are needed to better understand the PRL-R variants' role and their potential as therapeutic targets.

Letrozole Decreased Testosterone-Induced Cell Proliferation and Prolactin Secretion also Increased Apoptosis in MMQ and GH3 Rat Prolactinoma Cell Lines

Aromatase enzyme plays an essential role in estrogen-induced tumorigenesis. It is expressed in the normal pituitary and more significantly in prolactinoma tissues. The aim of this study was to investigate the effects of an aromatase inhibitor, letrozole, on MMQ and GH3 rat prolactinoma cell lines and evaluate the possible mechanism of action. MMQ and GH3 cells were characterized with demonstrating aromatase enzyme and estrogen receptor alpha expression by PCR and immunofluorescence staining. After dose optimization for testosterone (T) and letrozole (L), four groups were established: only the testosteron-treated group (T) to detect cell proliferation; only letrozole-treated group (L) to investigate apoptotic effects; testosterone and letrozole concomitant-treated group to demonstrate inhibition of testosterone induced cell proliferation with letrozole treatment s(T + L) and control group (C) with no treatment. The proliferation rate of cells was determined by WST-1. For the detection of apoptotic and necrotic cells, Annexin V and caspase-3 labeling was used. Prolactin and estrogen levels were measured with ELISA, and the mRNA expression of aromatase and Esr1 was also determined. Testosterone induced the proliferation of MMQ and GH3 cells and further increased prolactin and estradiol levels. Adding letrozole to testosterone resulted in decreased cellular proliferation and even induced apoptosis. Also, letrozole administration significantly decreased prolactin and estradiol levels. However, letrozole alone had no effects on proliferation and apoptosis. Gene expression of aromatase and Esr1 was also significantly decreased by letrozole treatment. This in vitro study demonstrated that treatment of testosterone proliferating cells with letrozole resulted in decreased prolactin levels and cell proliferation and induced apoptosis, and further loss of aromatase and Esr1 mRNA expression were observed. Although this is an in vivo study, the results showed unique and novel findings which may easily be adapted to clinical use for further verification.

Effect of Dopaminergic Therapy on Impulse Control Disorders in Patients With a Prolactinoma

BACKGROUND

Studies have reported an increase in the incidence of impulse control disorders (ICDs) in patient groups treated with dopamine agonists (DAAs), especially in Parkinson disease (PD). However, very few studies have reported on ICDs in individuals with a prolactinoma who were treated with DAAs.

OBJECTIVE

To see whether a DAA by itself causes ICDs in individuals with a prolactinoma by controlling the susceptibility to impulsivity by excluding individuals with other risk factors for ICDs.

METHOD

We compared the performance of 31 individuals with a prolactinoma receiving DAA therapy (DAA+) on various behavioral scales and the Iowa gambling task (IGT), a neuropsychological instrument that measures risky decision-making, with the performance of 20 individuals with a prolactinoma who were not on DAA therapy (DAA-) and 30 healthy controls (HC).

RESULTS

There was no significant difference among the groups concerning performance on the Zuckerman Sensation Seeking Scale-V, Minnesota Impulse Disorders Interview, Barratt Impulsiveness Scale-11, or IGT. No correlation was found between the scores on these scales and the duration or dose of DAA in the DAA+ group. The incidence of ICDs was 25.8% in the DAA+ group, 15% in the DAA- group, and 16.7% in the HC. The differences among the groups did not reach statistical significance.

CONCLUSION

Individuals who are under treatment with low-dose, D 2 -selective DAAs for a prolactinoma do not face an increased risk for ICDs, especially when they are carefully screened for any psychiatric comorbidity that may also display impulsivity.

11C-methionine PET aids localization of microprolactinomas in patients with intolerance or resistance to dopamine agonist therapy

PURPOSE

To assess the potential for ¹¹C-methionine PET (Met-PET) coregistered with volumetric magnetic resonance imaging (Met-PET/MR^CR) to inform clinical decision making in patients with poorly visualized or occult microprolactinomas and dopamine agonist intolerance or resistance.

PATIENTS AND METHODS

Thirteen patients with pituitary microprolactinomas, and who were intolerant (n = 11) or resistant (n = 2) to dopamine agonist therapy, were referred to our specialist pituitary centre for Met-PET/MR^CR between 2016 and 2020. All patients had persistent hyperprolactinemia and were being considered for surgical intervention, but standard clinical MRI had shown either no visible adenoma or equivocal appearances.

RESULTS

In all 13 patients Met-PET/MR^CR demonstrated a single focus of avid tracer uptake. This was localized either to the right or left side of the sella in 12 subjects. In one patient, who had previously undergone surgery for a left-sided adenoma, recurrent tumor was unexpectedly identified in the left cavernous sinus. Five patients underwent endoscopic transsphenoidal selective adenomectomy, with subsequent complete remission of hyperprolactinaemia and normalization of other pituitary function; three patients are awaiting surgery. In the patient with inoperable cavernous sinus disease PET-guided stereotactic radiosurgery (SRS) was performed with subsequent near-normalization of serum prolactin. Two patients elected for a further trial of medical therapy, while two declined surgery or radiotherapy and chose to remain off medical treatment.

CONCLUSIONS

In patients with dopamine agonist intolerance or resistance, and indeterminate pituitary MRI, molecular (functional) imaging with Met-PET/MR^CR can allow precise localization of a microprolactinoma to facilitate selective surgical adenomectomy or SRS.

Dopamine Agonist-Resistant Microprolactinoma—Mechanisms, Predictors and Management: A Case Report and Literature Review

Objective: Prolactinomas are the most common type of functional, hormone-secreting pituitary adenomas that account for about 40% of total pituitary adenomas. Typical clinical presentations include loss of menstrual periods (amenorrhea) and galactorrhoea in women and sexual dysfunction in men. Prolactinomas are preferentially treated with dopamine agonists and respond to such therapy with hormonal normalisation and tumour shrinkage. However, about 10–20% of prolactinomas are resistant to dopamine agonists. The management of dopamine agonist-resistant prolactinomas poses a therapeutic challenge and includes several possible approaches. Design and Methods: In this study, we present a case report of a woman diagnosed with microprolactinoma at the age of 27 who did not fully respond either to treatment with dopamine agonists nor to transsphenoidal surgery. This was followed by a review of literature on the current state of knowledge about the mechanisms, predictors, and management of dopamine agonist-resistant prolactinomas on the basis of recent scientific literature published up to November 2021 and searches of the PubMed, Google Scholar, and Web of Science databases. Results and Conclusions: The exact mechanisms underlying dopamine agonists’ resistance in lactotroph tumours are not fully understood, yet refractory prolactinomas pose a great challenge in everyday clinical practice. Several predictive factors that contribute to poor response to medical treatment have been identified, among them the elevated Ki-67 index. Recently, various alternative medical treatments have been considered, but their usefulness remains to be evaluated. A return of menses can serve as a first clinical indication of successful medical treatment.

The interplay between prolactin and cardiovascular disease

Hyperprolactinemia can be caused by several conditions and its effects on the hypothalamic-pituitary-gonadal axis are understood in more detail. Nevertheless, in recent decades, other metabolic effects have been studied and data pointed to a potential increased cardiovascular disease (CVD) risk. A recent study showed a decrease in total and LDL- cholesterol only in men with prolactinoma treated with dopamine agonists (DA) supporting the previous results of a population study with increased CVD risk in men harboring prolactinoma. However, other population studies did not find a correlation between prolactin (PRL) levels and CVD risk or mortality. There is also data pointing to an increase in high-density lipoprotein levels, and decreases in triglycerides, carotid-intima-media thickness, C-reactive protein, and homocysteine levels in patients with prolactinoma on DA treatment. PRL was also implicated in endothelial dysfunction in pre and postmenopausal women. Withdrawal of DA resulted in negative changes in vascular parameters and an increase in plasma fibrinogen. It has been shown that PRL levels were positively correlated with blood pressure and inversely correlated with dilatation of the brachial artery and insulin sensitivity, increased homocysteine levels, and elevated D-dimer levels. Regarding possible mechanisms for the association between hyperprolactinemia and CVD risk, they include a possible direct effect of PRL, hypogonadism, and even effects of DA treatment, independently of changes in PRL levels. In conclusion, hyperprolactinemia seems to be associated with impaired endothelial function and DA treatment could improve CVD risk. More studies evaluating CVD risk in hyperprolactinemic patients are important to define a potential indication of treatment beyond hypogonadism.

Aggressive prolactinoma (Review)

Aggressive prolactinoma (APRL) is a subgroup of aggressive pituitary tumors (accounting for 10% of all hypophyseal neoplasia) which are defined by: invasion based on radiological and/or histological features, a higher proliferation profile when compared to typical adenomas and rapidly developing resistance to standard medication/protocols in addition to an increased risk of early recurrence. This is a narrative review focusing on APRL in terms of both presentation and management. Upon admission, the suggestive features may include increased serum prolactin with a large tumor diameter (mainly >4 cm), male sex, early age at diagnosis (<20 years), and genetic predisposition [multiple endocrine neoplasia type 1 (MEN1), aryl hydrocarbon receptor interacting protein (AIP), succinate dehydrogenase (SDHx) gene mutations]. Potential prognostic factors are indicated by assessment of E-cadherin, matrix metalloproteinase (MMP)-9, and vascular endothelial growth factor (VEGF) status. Furthermore, during management, APRL may be associated with dopamine agonist (DA) resistance (described in 10-20% of all prolactinomas), post-hypophysectomy relapse, mitotic count >2, Ki-67 proliferation index ≥3%, the need for radiotherapy, lack of response in terms of controlling prolactin levels and tumor growth despite multimodal therapy. However, none of these as an isolated element serves as a surrogate of APRL diagnosis. A fourth-line therapy is necessary with temozolomide, an oral alkylating chemotherapeutic agent, that may induce tumor reduction and serum prolactin reduction in 75% of cases but only 8% have a normalization of prolactin levels. Controversies surrounding the duration of therapy still exist; also regarding the fifth-line therapy, post-temozolomide intervention. Recent data suggest alternatives such as somatostatin analogues (pasireotide), checkpoint inhibitors (ipilimumab, nivolumab), tyrosine kinase inhibitors (TKIs) (lapatinib), and mTOR inhibitors (everolimus). APRL represents a complex condition that is still challenging, and multimodal therapy is essential.

Outcomes of transsphenoidal surgery in dopamine agonist-resistant prolactinomas: a retrospective study

PURPOSE

Dopamine agonists (DA) comprise first-line treatment for prolactinomas. However, some patients show no response to DA and are considered resistant. In this study, we retrospectively analyzed the outcomes of DA-resistant prolactinoma patients after transsphenoidal surgery (TSS).

METHODS

A total of 94 consecutive patients with DA-resistant prolactinomas who underwent TSS were retrospectively enrolled in the present study. Early postoperative remission rate, prolactin (PRL) levels, and recurrence rate were analyzed.

RESULTS

Of 94 DA-resistant patients, 47 (50%) achieved early remission 1 week post-surgery, including 41.18% of macroprolactinoma patients and 73.08% of microprolactinoma patients. PRL levels on the first postoperative day were significantly lower than preoperative PRL levels (p < 0.001). Total resection rate in macro- and microprolactinomas were, respectively, 75 and 96.15%. A recurrence of hyperprolactinemia and tumor was, respectively, found in 31.91 and 19.15% of patients with a follow-up of 39.53 ± 2.172 months (range 3-86). A higher hyperprolactinemia recurrence was observed in patients with invasive prolactinomas (p = 0.021) or preoperative PRL levels ≥ 200 ng/ml (p = 0.029). Univariate logistic regression indicated that larger maximum tumor diameter (p = 0.045), invasive prolactinomas (p = 0.002), and absence of early postoperative remission (p = 0.004) were significant predictors of tumor recurrence. However, using multivariate stepwise logistic regression, only invasiveness and early postoperative remission remained significant.

CONCLUSION

Tumor invasiveness and preoperative PRL levels were significant predictors of hyperprolactinemia recurrence after TSS. For tumor recurrence, invasiveness and early postoperative remission were independent predictors.

Tumor volume improves preoperative differentiation of prolactinomas and nonfunctioning pituitary adenomas

PURPOSE

Both prolactinomas and nonfunctioning adenomas (NFAs) can present with hyperprolactinemia. Distinguishing them is critical because prolactinomas are effectively managed with dopamine agonists, whereas compressive NFAs are treated surgically. Current guidelines rely only on serum prolactin (PRL) levels, which are neither sensitive nor specific enough. Recent studies suggest that accounting for tumor volume may improve diagnosis. The objective of this study is to investigate the diagnostic utility of PRL, tumor volume, and imaging features in differentiating prolactinoma and NFA.

METHODS

Adult patients with pathologically confirmed prolactinoma (n = 21) or NFA with hyperprolactinemia (n = 58) between 2013 and 2020 were retrospectively identified. Diagnostic performance of clinical and imaging variables was analyzed using receiver-operating characteristic curves to calculate area under the curve (AUC).

RESULTS

Tumor volume and PRL positively correlated for prolactinoma (r = 0.4839, p = 0.0263) but not for NFA (r = 0.0421, p = 0.7536). PRL distinguished prolactinomas from NFAs with an AUC of 0.8892 (p < 0.0001) and optimal cut-off value of 62.45 ng/ml, yielding a sensitivity of 85.71% and specificity of 94.83%. The ratio of PRL to tumor volume had an AUC of 0.9647 (p < 0.0001) and optimal cut-off value of 21.62 (ng/ml)/cm³ with sensitivity of 100% and specificity of 82.76%. Binary logistic regression found that PRL was a significant positive predictor of prolactinoma diagnosis, whereas tumor volume, presence of cavernous sinus invasion, and T2 hyperintensity were significant negative predictors. The regression model had an AUC of 0.9915 (p < 0.0001).

CONCLUSIONS

Consideration of tumor volume improves differentiation between prolactinomas and NFAs, which in turn leads to effective management.

Determinants of Surgical Remission in Prolactinomas: A Systematic Review and Meta-Analysis

OBJECTIVE

Prolactin-secreting tumors respond well to medical management, with a few patients requiring surgery. We conducted a systematic review and meta-analysis to study the determinants of surgical remission in these tumors.

METHODS

We searched PubMed to identify eligible studies reporting postoperative remission in patients treated with transsphenoidal surgery for prolactinoma. Primary outcomes included postoperative remission, follow-up remission, and recurrence. Postoperative and follow-up remission were defined as normoprolactinemia at <1 year and >1 year after operation, respectively. Recurrence was defined as hyperprolactinemia after initial normalization of prolactin levels. Odds ratios (ORs) were calculated, stratified by radiologic size, tumor extension, and tumor invasion, and analyzed using a random-effects model meta-analysis.

RESULTS

Thirty-five studies were included. Macroadenomas were associated with lower rates of postoperative remission (OR, 0.20; 95% confidence interval [CI], 0.16-0.24) and lower rates of remission at follow-up (OR, 0.11; 95% CI, 0.053-0.22). Postoperative remission was less likely in tumors with extrasellar or suprasellar extension (OR, 0.16; 95% CI, 0.06-0.43) and tumors with cavernous sinus invasion (OR, 0.03; 95% CI, 0.01-0.13). Female gender and absence of preoperative dopamine agonist treatment were also associated with higher remission rates. Across the included studies, there was considerable heterogeneity in each primary outcome (postoperative remission, I² = 94%; follow-up remission, I² = 86%; recurrence, I² = 68%).

CONCLUSIONS

Transsphenoidal surgery for prolactinomas may be particularly effective in small, noninvasive, treatment-naive tumors and may provide a viable first-line alternative to dopamine agonist therapy in such patients.

"The Pituitary within GRASP" - Golden-Angle Radial Sparse Parallel Dynamic MRI Technique and Applications to the Pituitary Gland

MRI is the preferred radiologic modality for evaluating the pituitary gland. An important component of pituitary MRI examinations is dynamic contrast-enhanced MRI. Compared to conventional dynamic techniques, golden-angle radial sparse parallel (GRASP) imaging offers multiple advantages, including the ability to achieve higher spatial and temporal resolution. In this narrative review, we discuss dynamic imaging of the pituitary gland, the technical fundamentals of GRASP, and applications of GRASP to the pituitary gland.

Functional amyloids in the human body

Amyloids have long been associated with a variety of human degenerative diseases. Discoveries indicate, however, that there are several amyloids that serve functional roles in the human body. These amyloids are involved in a variety of biological processes ranging from storage of peptide hormones to necroptosis of cells. Additionally, there are distinct differences between toxic amyloids and their functional counterparts including kinetics of assembly/disassembly and structural features. This digest article surveys the biological roles of functional amyloids found in the human body, key differences between functional and toxic amyloids, and potential therapeutic applications.

Identification of an optimal prolactin threshold to determine prolactinoma size using receiver operating characteristic analysis

Prolactinomas represent the most common type of secretory pituitary neoplasms, with a therapeutic management that varies considerably based on tumour size and degree of hyperprolactinemia. The aim of the current study was to evaluate the relationship between serum prolactin (PRL) concentrations and prolactinoma size, and to determine a cut-off PRL value that could differentiate micro- from macro-prolactinomas. A retrospective cohort study of 114 patients diagnosed with prolactinomas between 2007 and 2017 was conducted. All patients underwent gadolinium enhanced pituitary MRI and receiver operating characteristic (ROC) analyses were performed. 51.8% of patients in this study were men, with a mean age at the time of diagnosis of 42.32 ± 15.04 years. 48.2% of the total cohort were found to have microadenomas. Baseline serum PRL concentrations were strongly correlated to tumour dimension (r = 0.750, p = 0.001). When performing the ROC curve analysis, the area under the curve was 0.976, indicating an excellent accuracy of the diagnostic method. For a value of 204 μg/L (4338 mU/L), sensitivity and specificity were calculated at 0.932 and 0.891, respectively. When a cut off value of 204 μg/L (4338 mU/L) was used, specificity was 93.2%, and sensitivity 89.1%, acceptable to reliably differentiate between micro- and macro- adenomas.

MicroRNA‑29‑3p regulates the β‑catenin pathway by targeting IGF1 to inhibit the proliferation of prolactinoma cells

The present study aimed to analyze the effects and underlying mechanisms of microRNA (miR)-29-3p on the proliferation and secretory abilities of prolactinoma cells by targeting insulin-like growth factor (IGF)-1/β-catenin. The relationship between miR-29a-3p and the survival of prolactinoma cells was analyzed with the Kaplan-Meier method in reference to The Cancer Genome Atlas. The expression levels of miR-29a-3p and IGF-1 in MMQ and GH3 cells were detected. A dual-luciferase reporter gene assay was performed to verify the combination of miR-29a-3p and IGF-1. Cells were transfected with a miR-29a-3p mimic and/or IGF-1 pcDNA3.1 to analyze the effects on the proliferation, apoptosis and secretion of prolactin (PRL) and growth hormone (GH) of prolactinoma cells. The effects on β-catenin in the cytoplasm and nucleus were investigated by western blot analysis. The results showed that miR-29a-3p expression was low in MMQ and GH3 cells. Overexpression miR-29a-3p inhibited IGF-1 mRNA and protein expression. miR-29a-3p inhibited cell proliferation and PRL and GH expression, and promoted apoptosis by inhibiting IGF-1. Increasing the expression of miR-29a-3p increased β-catenin levels in the cytoplasm, whereas IGF-1 promoted β-catenin activation and entry into the nucleus, and reversed the inhibitory effects of miR-29a-3p on β-catenin. To conclude, miR-29a-3p inhibited the proliferation and secretory abilities of prolactinoma cells by inhibiting nuclear translocation of β-catenin via a molecular mechanism that is inseparable from IGF-1.

Spontaneous Cerebrospinal Fluid Rhinorrhea from a Prolactin-Secreting Pituitary Macroadenoma

Cerebrospinal fluid (CSF) rhinorrhea is a rare complication of macroprolactinomas that, in the vast majority of cases, is subsequent to either medical or surgical intervention. Here, we present the successful management of a rare case of spontaneous, noniatrogenic CSF rhinorrhea in a patient with an untreated macroprolactinoma. A 27-year-old man with no significant medical history presented with six months of persistent CSF rhinorrhea, which was confirmed by testing for beta-2-transferrin. He had had decreased libido since adolescence and impaired growth of secondary sexual characteristics. Workup revealed an elevated prolactin level, and imaging demonstrated erosion of the anterior sellar floor and soft tissue within the sphenoid sinus, concerning for tumor. The patient underwent surgical repair of the CSF leak via a transnasal transsphenoidal approach, with resection and biopsy of tumor material within the sinus. No tumor was noted within the sella itself. The patient tolerated the procedure well and had subsequent normalization of his prolactin level with no further CSF egress. Spontaneous noniatrogenic CSF rhinorrhea, although rare, should be considered in the differential diagnosis of invasive pituitary macroadenomas, especially prolactinomas. The mechanism of CSF leak from a prolactinoma is not completely understood, but the CSF leak should be urgently repaired through a transnasal transsphenoidal approach. Concurrently, tumor resection should be performed and a postoperative lumbar puncture or lumbar drain should be considered to reinforce the skull base reconstruction.

Biochemical Remission after Cabergoline Withdrawal in Hyperprolactinemic Patients with Visible Remnant Pituitary Adenoma

CONTEXT

Dopamine agonists (DAs) are the first-line therapy for prolactinomas. Although pituitary tumors often do not completely disappear, discontinuing DAs in patients with no visible tumor on magnetic resonance imaging is advised.

OBJECTIVE

To analyze biochemical remission after cabergoline (CAB) withdrawal in patients with visible remnant pituitary tumors.

DESIGN

Retrospective cohort study.

SETTING

Severance Hospital.

SUBJECTS

We identified 734 patients with prolactinomas undergoing CAB therapy for at least 12 months from 2005 to 2018. We selected 44 patients with prolactinomas who discontinued CAB with normal prolactin levels; they were receiving a minimal CAB dose but had visible remnant tumors.

RESULTS

Median age at diagnosis was 32 (18-58) years, and most patients were women (95.45%). Median treatment duration was 32 (12-120) months. Of 44 patients, 33 continued to have normoprolactinemia, but 11 patients developed hyperprolactinemia after drug withdrawal within 26 (12-97) months. Age, sex, maximal and remnant tumor size, and treatment duration were similar between the groups. The initial prolactin level and chances of cavernous sinus (CS) invasion were higher in the recurrence group. CS invasion at diagnosis was associated with an increased recurrence rate. Although treatment response did not correlate with the initial and final signal intensity assessments, a significant decrease in T2 intensity ratio after 6 months of CAB therapy was observed in the remission group (P = .043).

CONCLUSION

In patients with visible tumors, the presence of CS invasion at diagnosis may be an unfavorable predictor for biochemical remission after CAB discontinuation.

Retinal layers in prolactinoma patients: a spectral-domain optical coherence tomography study

PURPOSE

Prolactinoma is a type of pituitary tumour that produces an excessive amount of the hormone prolactin. It is the most common type of hormonally-active pituitary tumour. These tumours can cause ocular complications such as vision loss and visual fields (VF) defect. In this study, we aimed to evaluate the thickness of chorioretinal layers in patients with prolactinoma.

METHODS

We enrolled 63 eyes of 32 prolactinoma patients and 36 eyes of 18 age and gender-matched healthy controls. All participants underwent complete hormonal and ophthalmological examination, including spectral-domain optical coherence tomography (SD-OCT) and VF test.The complete biochemical response was defined as serum PRL concentration ≤ 20 ng/mL at the time of evaluation.The seven layers were retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), and retinal pigment epithelium (RPE). The results of prolactinoma patients were compared with the control group.

RESULTS

The mean RNFL, GCL, IPL, INL, ONL, and RPE were thinner in prolactinoma patients than the control group (p < 0.05) while OPL was similar between groups (p > 0.05).None of the patients had VF defect.The thickness of retinal layers was similar in patients with and without complete biochemical response (p > 0.05).

CONCLUSION

To our knowledge, this is the first study that evaluates the thickness of chorioretinal layers in patients with prolactinoma.Most of the layers were thinner than the control group.Therefore, detailed eye assessment should be a routine component of the follow-up visits of prolactinoma patients and further studies related to this condition are required.

PBK/TOPK Inhibitor Suppresses the Progression of Prolactinomas

BACKGROUND

Prolactinoma is the most common type of pituitary tumors, and its resultant tumor occupying and hormone disturbance greatly damage the health of patients. In this study, we investigated a protein kinase-PDZ Binding Kinase (PBK)/T-LAK Cell-Originated Protein Kinase (TOPK) as a candidate protein regulating prolactin (PRL) secretion and tumor growth of prolactinomas.

METHODS

Downloaded prolactinoma transcriptome dataset from Gene Expression Omnibus (GEO) database, and screened differentially expressed genes (DEGs) between normal pituitary tissues and prolactinoma tissues. Then, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed, a protein-protein interaction (PPI) network was constructed and the hub genes were identified. After a literature search, TOPK was presumed as an candidate target regulating the prolactinoma. We found a specific inhibitor of TOPK to investigate its effects on the proliferation, migration, apoptosis and PRL secretion of pituitary tumor cells. Finally, the regulation of TOPK inhibitor on its downstream target-p38 Mitogen Activated Protein Kinase (p38 MAPK) was detected to explore the potential mechanism.

RESULTS

A total of 361 DEGs were identified, and 20 hub genes were screened out. TOPK inhibitor HI-TOPK-032 could suppress the proliferation & migration and induce apoptosis of pituitary tumor cells in vitro, and reduce PRL secretion and tumor growth in vivo. HI-TOPK-032 also inhibited the phosphorylation level of the downstream target p38 MAPK, suggesting that TOPK inhibitors regulate the development of prolactinoma by mediating p38 MAPK.

CONCLUSION

Our study of identification and functional validation of TOPK suggests that this candidate can be a promising molecular target for prolactinoma treatment.

Outcomes of surgical and/or medical treatment in patients with prolactinomas during long-term follow-up: a retrospective single-centre study

OBJECTIVES

Prolactinoma is the most common cause of pituitary tumours. Current medical guidelines recommend dopamine agonists (cabergoline or bromocriptine) as the initial therapy for prolactinoma. However, surgical removal can also be considered in selected cases, such as patients with macroadenomas with local complications (bleeding or optic chiasm pressure) or those not responding to medical treatment.

METHODS

The present retrospective study included patients with prolactinomas (n=43; female, 24; male, 19) who were primarily managed with medical (n=32) or surgical (n=11) treatment.

RESULTS

Macroadenoma (n=29.67%) was commonly detected in both genders (female, 54%; male, 84%). Moreover, the mean pre-treatment prolactin levels were similar in both genders (female, 683.3 ± 1347 ng/mL; male, 685.4 ± 805 ng/mL; p=0.226). Surgically treated patients had a greater reduction in tumour size (27.7 ± 17.9 mm pre-treatment vs. 8.72 ± 14.2 mm post-treatment) than non-surgically treated ones (12.5 ± 7.5 mm pre-treatment vs. 4.1 ± 4.2 mm post-treatment; p=0.00). However, the decrease in prolactin levels was similar between the two patient groups (p=0.108). During the follow-up period (10.6 ± 7.0 years), the average cabergoline dose of the patients was 1.42 ± 1.47 mcg/week.

CONCLUSIONS

Although a surgical approach was considered for selected cases of prolactinoma, the average dose used for medical treatment was highly inadequate for the patients in the present study.

17β-estradiol binding to ERα promotes the progression of prolactinoma through estrogen-response element-induced CaBP-9k up-regulation

17β-estradiol (E2) is considered to be an important instigator of prolactinoma, and can positively regulate the expression of calbindin-D9k (CaBP-9k) which contains an estrogen responsive element (ERE) via estrogen receptors (ERs). However, the detailed mechanism of E2 in promoting CaBP-9k expression and their roles in prolactinoma progression remain unclear. Here, we aimed to characterize it. The luciferase gene reporter assay with luc-ERE transfection showed that E2 treatment significantly enhanced the transcriptional level of CaBP-9k, whereas CaBP-9k activity was reduced when GH3 and MMQ cells were treated with AZD9496, an antagonist of ERα. E2 treatment increased the protein expressions of CaBP-9k and ERα but not ERβ, whereas this effect was also abolished when cells were treated with AZD9496. Besides, immunoprecipitation (IP) and immunofluorescence assays demonstrated that CaBP-9k could directly interact with ERα not ERβ, and Chromatin IP (ChIP) assay showed that ERα could bind to ERE of the CaBP-9k promoter. Moreover, cell counting kit-8 (CCK-8) and flow cytometry assays showed that E2 treatment significantly enhanced cell viability and inhibited cell apoptosis, but these effects were all abolished when ERα was down-regulated by short hairpin RNA (shRNA) or inhibited by AZD9496, as well as CaBP-9K suppression in both GH3 and MMQ cell lines. Taken together, these findings indicated that E2 stimulation promoted prolactin cell proliferation and inhibited cell apoptosis through ERα-induced CaBP-9k up-regulation, which then accelerated the advanced progression of prolactinoma.

SF-12 or SF-36 in pituitary disease? Toward concise and comprehensive patient-reported outcomes measurements

PURPOSE

Pituitary diseases severely affect patients' health-related quality of life (HRQoL). The most frequently used generic HRQoL questionnaire is the Short Form-36 (SF-36). The shorter 12-item version (SF-12) can improve efficiency of patient monitoring. This study aimed to determine whether SF-12 can replace SF-36 in pituitary care.

METHODS

In a longitudinal cohort study (August 2016 to December 2018) among 103 endoscopically operated adult pituitary tumor patients, physical and mental component scores (PCS and MCS) of SF-36 and SF-12 were measured preoperatively, and 6 weeks and 6 months postoperatively. Chronic care was assessed with a cross-sectional study (N = 431). Mean differences and agreement between SF-36 and SF-12 change in scores (preoperative vs. 6 months) were assessed with intraclass correlation coefficients (ICC) and limits of agreement, depicting 95% of individual patients.

RESULTS

In the longitudinal study, mean differences between change in SF-36 and SF-12 scores were 1.4 (PCS) and 0.4 (MCS) with fair agreement for PCS (ICC = 0.546) and substantial agreement for MCS (ICC = 0.931). For 95% of individual patients, the difference between change in SF-36 and SF-12 scores varied between -14.0 and 16.9 for PCS and between -7.8 and 8.7 for MCS. Cross-sectional results showed fair agreement for PCS (ICC = 0.597) and substantial agreement for MCS (ICC = 0.943).

CONCLUSIONS

On a group level, SF-12 can reliably reproduce MCS in pituitary patients, although PCS is less well correlated. However, individual differences between SF-36 and SF-12 can be large. For pituitary diseases, alternative strategies are needed for concise, but comprehensive patient-reported outcome measurement.

Gamma Knife Radiosurgery (GKRS) for Patients with Prolactinomas: Long-Term Results From a Single-Center Experience

Background

The aim of this study was to review outcomes of gamma knife radiosurgery (GKRS) for prolactinoma and report our experience with it.

Material/Methods

We reviewed the patient database in our center and identified 24 patients with prolactinoma who underwent GKRS from 1993 to 2016. Complete endocrine, clinical, and radiological data were available on these individuals before and after GKRS.

Results

Data from 5 males and 19 females with a median age of 30.5 years (range, 18.1 to 51.1) were reviewed. The median follow-up was 109.3 months (range, 23.2–269.3). The median margin dose of GKRS was 15 Gy (range, 10.5 to 23.6). In total, prolactin (PRL) normalization after GKRS was achieved in 66.7% of patients. Endocrine remission (normal PRL levels after discontinuation of dopamine agonists) was achieved in 10 patients (41.7%), and endocrine control (normal PRL levels while taking dopamine agonists) was achieved in 6 patients (25.0%). All of the patients showed tumor control. New-onset hypopituitarism post-GKRS occurred in 4 patients (16.7%). No new visual dysfunction or cranial nerve dysfunction were observed after GKRS.

Conclusions

For treatment of prolactinomas, GKRS may provide relatively high rates of endocrine remission and tumor control, as well as a low rate of new-onset hypopituitarism. GKRS may be an effective and safe treatment for prolactinomas.

Inhibition of lncRNA-UCA1 suppresses pituitary cancer cell growth and prolactin (PRL) secretion via attenuating glycolysis pathway

Pituitary tumor is one type of endocrine tumor with high incidence and mortality rates. Long non-coding RNAs (lncRNAs) are a family of non-coding RNAs with longer than 200 nucleotides. Among them, lncRNA-UCA1 is highly expressed in multiple cancers and plays critically oncogenic roles in tumor progressions. However, the potential roles of UCA1 in human pituitary tumor have not been elucidated. In this study, the expressions of lncRNA-UCA1 were analyzed in thirty pituitary tumor samples and thirty normal pituitary tissues. Cancer cell glycolysis rate was examined by glucose uptake and lactate production. The lncRNA-UCA1 expression was detected by qRT-PCR. Glycolysis enzyme expressions were measured by Western blot and qRT-PCR. Consistent with other cancers, lncRNA-UCA1 was highly expressed in pituitary tumors. Meanwhile, we found glycolysis of pituitary tumors was higher than normal pituitary tissues. Overexpression of lncRNA-UCA1 in rat pituitary cancer cell lines, GH3 and MMQ, significantly promoted glucose uptake and lactate production. In addition, expressions of the glycolysis key enzymes, HK2 and LDHA, were significantly upregulated by exogenous overexpression of lncRNA-UCA1. Importantly, silencing lncRNA-UCA1 obviously inhibited pituitary cancer cells growth and prolactin (PRL) secretion. We report higher lncRNA-UCA1 expression is associated with higher serum PRL level in pituitary patients. Finally, by blocking the lncRNA-UCA1-promoted glycolysis of pituitary cancer cells by glycolysis inhibitor, 2-DG, we obtained recovery of cell growth rate and PRL secretion from an in vitro model. Taken together, our investigation revealed an oncogenic role of lncRNA-UCA1 through upregulating glycolysis of pituitary tumors. This study contributes to underlying molecular mechanisms of the tumorigenesis of pituitary tumors.

A single- center experience of prolactin-producing pituitary adenomas without hyperprolactinemia: Its incidence and clinical management

OBJECTIVE

This study clarifies the incidence of prolactin-producing pituitary adenomas without hyperprolactinemia and determines the appropriate treatment strategy for these tumors.

PATIENTS AND METHODS

This retrospective analysis focused on prolactin-producing adenomas without hyperprolactinemia, which were initially treated by surgery as nonfunctioning pituitary adenomas. Among 942 patients with histologically confirmed pituitary adenoma, 114 (12.1 %) patients, consisting of 68 men and 46 women, who had prolactin-producing adenomas without hyperprolactinemia were identified between April 2005 and March 2019.

RESULTS

Of the 114 patients identified, 13 (11.4 %) had prolactin mono-expressions, 18 (15.8 %) had pit-1 lineage hormonal expressions, and 83 (72.8 %) had paradoxical immunoexpression out of the pituitary differentiation lineage, including prolactin. During the follow-up period, 19 patients suffered tumor progression, and 14 required salvage treatment. Of the 19 patients, 11 underwent gamma knife radiosurgery, and none of them experienced further tumor progression. Cabergoline was administered of them to six patients, and one achieved tumor shrinkage. However, the remaining five patients who were treated with cabergoline suffered further tumor progression and required another salvage treatment. Among the patients in the prolactin mono-expression group, one experienced tumor regrowth and underwent gamma knife radiosurgery. In the pit-1 lineage group, two patients experienced tumor regrowth. One had further tumor progression after treatment with cabergoline and underwent gamma knife radiosurgery. Among the patients in the paradoxical immunoexpression group, 16 suffered tumor progression. Four patients underwent further surgery, seven patients were treated with gamma knife radiosurgery, and one patient received fractionated irradiation. None of the eight patients who were treated with gamma knife radiosurgery and fractionated irradiation showed further tumor progression. Four patients in this group were treated with cabergoline, but they all suffered further tumor progression and underwent additional salvage treatments.

CONCLUSIONS

Out of the pituitary differentiation lineage, paradoxical hormonal expression occurred in three-quarters of the patients identified. Further surgery or gamma knife radiosurgery should be given priority in times of tumor progression because most patients were resistant to dopamine agonists.

Prolactinomas in pregnancy: considerations before conception and during pregnancy

Prolactinomas are the most common pituitary tumors and pathological hyperprolactinemia. Therefore, women harboring prolactinomas frequently present infertility due to the gonadal axis impairment. The gold-standard treatment is dopamine agonist (DA) which can reverse hyperprolactinemia and hypogonadism, and promote tumor shrinkage in the majority of cases. Therefore, reports of pregnancy in such cohort become more common. In this scenario, bromocriptine is still the DA of choice due to its shorter half-life and larger experience as compared to cabergoline. In DA resistant cases, transsphenoidal pituitary surgery is indicated. However, potential risks of DA-induced pregnancies include fetal exposition and symptomatic tumor growth. Dopamine agonist should be discontinued as soon as pregnancy is confirmed in microprolactinomas and intrasellar macroprolactinomas (MAC). Concerning expansive/invasive MAC, DA maintenance should be considered. Periodically clinical evaluation should be performed during pregnancy, being sellar imaging indicated if tumor symptomatic growth is suspected. In such cases, if DA treatment fails, neurosurgery is indicated.

Acute effects of somatomammotropin hormones on neuronal components of the hypothalamic-pituitary-gonadal axis

Growth hormone (GH) and prolactin (PRL) are known as pleiotropic hormones. Accordingly, the distribution of their receptors comprises several organs and tissues, including the central nervous system. The appropriate secretion of both hormones is essential for sexual maturation and maintenance of reproductive functions, while defects in their secretion affect puberty onset and can cause infertility. Conversely, GH therapy at a prepubertal age may accelerate puberty. On the other hand, hyperprolactinemia is a frequent cause of infertility. While the action of PRL in some central components of the Hypothalamic-Pituitary-Gonadal (HPG) axis, such as the kisspeptin neurons, has been well documented, the possible effects of GH in the hypothalamus are still elusive. Thus, the present study was designed to investigate whether somatomammotropin hormones are able to modulate the activity of critical neuronal components of the HPG axis, including kisspeptin neurons and cells of the ventral premammillary nucleus (PMv). Our results revealed that GH effects in kisspeptin neurons of the anteroventral periventricular and rostral periventricular nuclei or in PMv neurons relies predominantly on the recruitment of the signal transducer and activator of transcription 5 (STAT5) rather than through acute changes in resting membrane potential. Importantly, kisspeptin neurons located at the arcuate nucleus were not directly responsive to GH. Additionally, our findings further identified PMv neurons as potential targets of PRL, since PRL induces the phosphorylation of STAT5 and depolarizes PMv neurons. Combined, our data provide evidence that GH and PRL may affect the HPG axis via specific hypothalamic neurons.

Aggressive and Malignant Prolactinomas

Prolactin-secreting tumors (prolactinomas) represent the most common pituitary tumor type, accounting for 47-66% of functional pituitary tumors. Prolactinomas are usually benign and controllable tumors as they express abundant levels of dopamine type 2 receptor (D2), and can be treated with dopaminergic drugs, effectively reducing prolactin levels and tumor volume. However, a proportion of prolactinomas exhibit aggressive features (including invasiveness, relevant growth despite adequate dopamine agonist treatment, and recurrence potential) and few may exhibit metastasizing potential (carcinomas). In this context, the clinical, pathological, and molecular definitions of malignant and aggressive prolactinomas remain to be clearly defined, as primary prolactin-secreting carcinomas are similar to aggressive adenomas until the presence of metastases is detected. Indeed, standard molecular and histological analyses do not reflect differences between carcinomas and adenomas at a first glance and have limitations in prediction of the aggressive progression of prolactinomas, wherein the causes underlying the aggressive behavior remain unknown. Herein we present a comprehensive, multidisciplinary review of the most relevant epidemiological, clinical, pathological, genetic, biochemical, and molecular aspects of aggressive and malignant prolactinomas.

Neurosurgical anesthesia for a pregnant woman with macroprolactinoma: A case report

RATIONALE

Being required to perform neurosurgery on a pregnant woman is rare, but occasionally unavoidable. In these cases, clinical anesthesiologists are confronted with conflicting information and few evidence-based guidelines.

PATIENT CONCERNS

Here, we describe the successful anesthetic management of a 24-week pregnant woman with macroprolactinoma who underwent endonasal transsphenoidal resection of pituitary adenoma.

DIAGNOSES

According to the prolactin (PRL) level and magnetic resonance imaging (MRI) results, the patient was diagnosed with macroprolactinoma and kept stable after taking the regular bromocriptine treatment. However, after stopping the drug by herself because of pregnancy, her tumor increased in size and she suffered from vision loss. Surgery was recommended as soon as possible to lessen the compression in the eye. However, the anesthetic management was a considerable risk due to the increased chance of maternal mortality, intrauterine growth restriction, or preterm labor.

INTERVENTIONS

We held a multidisciplinary meeting before the operation and made a detailed plan for how to proceed. During the operation, our team ensured intensive monitoring, provided adequate oxygen, and achieved haemodynamic stability. Anesthetics like sufentanyl, rocuronium, propofol, and desflurane were carefully chosen in order to ensure the safety of both the mother and fetus.

OUTCOMES

Under the careful and successful anesthetic management, the pregnant woman underwent the surgery smoothly and neither the mother nor baby experienced any pre- or postoperative complications. At the 38th week of gestation, the patient received a cesarean section and the baby had developed normally.

LESSONS

Neurosurgeries in pregnancy are sparse, and careful planning with cross-disciplinary specialists was needed in advance of the operation. Moreover, when dealing with such surgeries, we should consider the safety of both the mother and fetus, which is challenging but important.

Myasthenia gravis imitating pituitary apoplexy in macroprolactinoma

Myasthenia gravis (MG) is an autoimmune disease affecting neuromuscular transmission that manifests with muscle weakness and typically involves the eye muscles, often producing diplopia and ptosis. Recent studies suggest that hyperprolactinaemia may have a role in the development of MG, although its association with prolactinoma is extremely rare. We report the unusual case of a 71-year-old male affected with macroprolactinoma, who presented at our Center 2 weeks after starting cabergoline treatment because of acute onset of headache, diplopia, and ptosis. On admission, he presented with drowsiness, dropped head, swallowing impairment and bilateral ptosis, which rapidly worsened. Based on clinical manifestation and history, emergency surgery was performed on suspicion of pituitary apoplexy (PA), the typical complication occurring in patients with macroadenomas who present these symptoms. No pituitary haemorrhage was found. The symptoms initially resolved after surgery, but soon returned and worsened day by day, especially in the evening, despite the increase of cortisone replacement doses. MG was thus suspected and confirmed by the detection of antibodies to the acetylcholine receptor. Pyridostigmine was started with prompt improvement of neurological symptoms. In conclusion, although very rare, MG should be considered in the differential diagnosis of patients with macroprolactinomas and suggestive neurological symptoms in order to provide early and appropriate treatment. The role of hyperprolactinaemia in MG onset and evolution is also discussed.

Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

STAT5 signaling in kisspeptin cells regulates the timing of puberty

Previous studies have shown that kisspeptin neurons are important mediators of prolactin's effects on reproduction. However, the cellular mechanisms recruited by prolactin to affect kisspeptin neurons remain unknown. Using whole-cell patch-clamp recordings of brain slices from kisspeptin reporter mice, we observed that 20% of kisspeptin neurons in the anteroventral periventricular nucleus was indirectly depolarized by prolactin via an unknown population of prolactin responsive neurons. This effect required the phosphatidylinositol 3-kinase signaling pathway. No effects on the activity of arcuate kisspeptin neurons were observed, despite a high percentage (70%) of arcuate neurons expressing prolactin-induced STAT5 phosphorylation. To determine whether STAT5 expression in kisspeptin cells regulates reproduction, mice carrying Stat5a/b inactivation specifically in kisspeptin cells were generated. These mutants exhibited an early onset of estrous cyclicity, indicating that STAT5 transcription factors exert an inhibitory effect on the timing of puberty.

Management of prolactinomas: a survey of physicians from the Middle East and North Africa

BACKGROUND

Prolactinomas are the commonest functional tumors of the pituitary gland. There are still controversies regarding medical therapy in specific clinical situations. Patients may be managed by different specialists in the Middle East and North Africa (MENA) region and no data exist on patterns of clinical management.

OBJECTIVES

To ascertain the diagnostic and therapeutic approaches to prolactinomas among relevant professionals from the MENA region.

METHODS

An online survey of a large sample of physicians was conducted. The questionnaire covered various aspects of diagnosis and treatment of prolactinomas. 468 respondents were included; 36 % were endocrinologists; 49 % worked in public facilities and 81 % graduated more than 10 years. 40 and 30 % would have seen 1-5 and more than 5 suspected or confirmed prolactinomas over a 6 months period, respectively.

RESULTS

Regarding the diagnosis, 30 % of the respondents considered that prolactin levels <100 ng/ml exclude the presence of a prolactinoma. 21 % of respondents considered prolactin levels >250 ng/ml compatible with macroprolactinomas only, whereas others accepted this to be compatible also with microprolactinomas, macroprolactinaemia and drug-induced hyperprolactinemia (50, 42 and 36 % respectively). 71 % of respondents favored the screening for macroprolactin in asymptomatic individuals with hyperprolactinemia. Regarding the treatment, 84 % of respondents would treat microprolactinomas even in the absence of symptoms whereas 72 % of the respondents would treat microprolactinomas only if symptoms exist. 60 and 49 % of the respondents chose cabergoline as the drug of choice to treat macroprolactinomas and microprolactinomas respectively. Similar proportions had no preference of either cabergoline or bromocriptine as the best treatment for macroprolactinoma (27 %) and microprolactinomas (32 %). 46 and 75 % of respondents favored treatment withdrawal 2-3 years after prolactin normalization in patients with macroprolactinomas and microprolactinomas, respectively whereas 10 % of respondents withdraw treatment after menopause in either case. 94 % of respondents considered medical therapy as the primary treatment for microprolactinomas. In case of pregnancy, 49 % considered bromocriptine as the drug of choice for women who wish to become pregnant. 65 and 38 % of respondents advocated discontinuation of treatment with dopamine agonists in patients with microprolactinomas and macroprolactinomas, respectively. Finally, 48 % would allow breast-feeding without restriction, 28 % would restrict it to patients with microprolactinomas and 25 % would not recommend it for women with prolactinomas.

CONCLUSIONS

This is the first study of the clinical management of prolactinomas in the MENA region. Some of the practices are not in line with the latest Endocrine and Pituitary Societies guidelines. These warrant further discussions of contemporary guidelines in regional forums.

Therapeutic effects of Schisandra chinensis on the hyperprolactinemia in rat

Prolactin (PRL) is secreted from the pituitary gland in response to eating, mating, and ovulation. Increased serum concentration of PRL during pregnancy contributes to enlargement of the mammary glands of the breasts and prepares for production of milk. However, high PRL levels derived from prolactinoma and hyperprolactinemia induce physiological disorders such as infertility and early menopause. Natural compounds isolated from S. chinensis have been known to possess anti-oxidative, anti-inflammatory and anti-diabetic effects. In the present study, we examined the therapeutic effect of S. chinensis and its single compounds on hyperprolactinemia in the pituitary gland. In rat pituitary cells, PRL expression levels were examined using real-time PCR and western blot assay. Crude S. chinensis extract and its single compound, gomisin N, reduced mRNA and protein levels of PRL in GH3 cells. In addition, cell proliferation and PRL target gene expression in cells were modulated by S. chinensis. Similar to the in vitro experiments, crude S. chinensis extract and gomisin N reduced PRL levels in the pituitary and serum of immature female rats. These results show that S. chinensis and its single compound, gomisin N, are regulators of PRL production and may be candidates for treatment of hyperprolactinemia and prolactinoma.

Guidelines for the management of neuroendocrine tumours by the Brazilian gastrointestinal tumour group

Neuroendocrine tumours are a heterogeneous group of diseases with a significant variety of diagnostic tests and treatment modalities. Guidelines were developed by North American and European groups to recommend their best management. However, local particularities and relativisms found worldwide led us to create Brazilian guidelines. Our consensus considered the best feasible strategies in an environment involving more limited resources. We believe that our recommendations may be extended to other countries with similar economic standards.

Interactions between prolactin and kisspeptin to control reproduction

Prolactin is best known for its effects of stimulating mammary gland development and lactogenesis. However, prolactin is a pleiotropic hormone that is able to affect several physiological functions, including fertility. Prolactin receptors (PRLRs) are widely expressed in several tissues, including several brain regions and reproductive tract organs. Upon activation, PRLRs may exert prolactin's functions through several signaling pathways, although the recruitment of the signal transducer and activator of transcription 5 causes most of the known effects of prolactin. Pathological hyperprolactinemia is mainly due to the presence of a prolactinoma or pharmacological effects induced by drugs that interact with the dopamine system. Notably, hyperprolactinemia is a frequent cause of reproductive dysfunction and may lead to infertility in males and females. Recently, several studies have indicated that prolactin may modulate the reproductive axis by acting on specific populations of hypothalamic neurons that express the Kiss1 gene. The Kiss1 gene encodes neuropeptides known as kisspeptins, which are powerful activators of gonadotropin-releasing hormone neurons. In the present review, we will summarize the current knowledge about prolactin's actions on reproduction. Among other aspects, we will discuss whether the interaction between prolactin and the Kiss1-expressing neurons can affect reproduction and how kisspeptins may become a novel therapeutic approach to treat prolactin-induced infertility.