Pituitary disorders during pregnancy

Pituitary Apoplexy in Pregnancy: What do We Know?

Pituitary apoplexy refers to a rare clinical syndrome consisting of signs and symptoms that occur due to rapid expansion of the contents of the sella turcica. It can occur spontaneously or associated with pituitary tumors. It can have a broad clinical spectrum, but usually presents with severe headache, visual impairment and hypopituitarism. Sudden onset of symptoms associated to imagiologic confirmation makes the diagnosis. Surgical treatment is advised when there is important compression of the optic tract. We present a case report and a review of the literature on pituitary apoplexy in pregnancy. The cases were reviewed to obtain information on maternal characteristics, clinical presentation, diagnostic studies, therapeutic modalities and maternal and fetal outcomes. Our review found 36 cases of pituitary apoplexy in pregnancy. Most of the cases occurred in the second trimester of pregnancy and headache was the most frequent symptom at presentation. Surgical therapy was required in more than half of the patients. In what respect maternal and fetal outcomes, there were 3 cases of preterm delivery and one case of maternal death. Our clinical case and literature review reinforces the importance of an early diagnosis to avoid potential adverse consequences.

Dopamine agonists for the treatment of pituitary tumours: From ergot extracts to next generation therapies

Dopamine agonists are a key tool in the therapeutic arsenal of endocrinologists worldwide. They exert their effects by binding to dopamine-2 (D2) receptors expressed by pituitary tumour cells to modulate hormonal secretion and tumour size. They are the established first-line treatment for prolactinomas which express high levels of D2 receptors. Growing data support their use as an adjuvant treatment option for other pituitary tumours including growth hormone, adrenocorticotrophic hormones, thyroid hormone secreting adenomas and nonfunctional pituitary tumours, all of which have been shown to express D2 receptors as well, albeit to varying extents. For those pituitary tumours inadequately treated by dopamine agonist alone, combined agonism of D2 and somatostatin receptors represent a new frontier in clinical development. Here we review the development and role of dopamine agonist for the treatment of prolactinomas, the literature supporting their adjuvant use for the treatment of all other pituitary tumours, and recent progress in the development of the next generation of chimeric compounds that target D2 and other receptor subtypes highly expressed on pituitary tumour cells.

Prolactin and Other Pituitary Disorders in Kidney Disease

Prolactin levels are increased in chronic kidney disease (CKD) as a result of reduced clearance and increased secretion. Hyperprolactinemia manifests as galactorrhea and hypogonadism. Treatment of hyperprolactinemia should focus on improving bothersome galactorrhea or hypogonadism by using dopamine agonists and/or replacement of sex hormone(s). Changes in the hypothalamic-pituitary-adrenal axis in CKD are characterized by increases in adrenocorticotropic hormone (ACTH) and cortisol levels, largely preserved circadian rhythms of ACTH and cortisol, and a normal response of cortisol to ACTH, metyrapone, and insulin-induced hypoglycemia. However, the hypothalamic-pituitary-adrenal axis is less inhibited by 1 mg dexamethasone but retains normal suppression by higher-dose dexamethasone. Diagnosis of adrenal insufficiency in CKD patients, as in normal subjects, usually is made by finding a subnormal cortisol response to ACTH. The mainstay of treatment of adrenal insufficiency is to replace glucocorticoid hormone. Cushing's disease in CKD is difficult to diagnose and relies on the dexamethasone suppression test and the midnight salivary cortisol test because the 24-hour urine free cortisol test is not useful because it is increased already in CKD. Treatment of Cushing's disease involves surgery, complemented by radiation and/or medical therapy if necessary. Growth hormone levels are increased and insulin-like growth factor 1 levels are normal in patients with CKD. In a normal patient with CKD, as in one with acromegaly, there can be a paradoxic increase in growth hormone after an oral glucose load. Therefore, diagnosis of acromegaly in renal insufficiency is challenging. The treatment of choice for acromegaly is surgery, although data for medical treatment for acromegaly in CKD are rare. In patients with renal impairment, arginine vasopressin levels are increased as a result of decreased clearance, and there also is impairment of arginine vasopressin signaling in renal tubules. Diabetes insipidus can be masked in advanced kidney disease until kidney transplantation. Diagnosis of the syndrome of inappropriate antidiuretic hormone is similar in mild or moderate kidney disease as in normal subjects, but is challenging in patients with advanced kidney disease owing to the impairment in urine dilution.

Magnetic resonance imaging in the management of prolactinomas; a review of the evidence

PURPOSE

This review aimed to evaluate data on the use of magnetic resonance imaging in the management of prolactinomas.

METHODS

Recent literature about prolactinoma behavior and magnetic resonance imaging in the management of prolactinomas is reviewed.

RESULTS

A review of evidence regarding prolactinoma pituitary MRI follow-up; techniques and sequences, recent data on possible gadolinium retention, the role and a review of T2-weighted images in the identification of prolactinomas and frequently encountered clinical scenarios, as well as MRI correlation with prolactin secretion, tumor growth and prediction of response to medical therapy are presented.

CONCLUSION

The underlying decision to perform serial imaging in prolactinoma patients should be individualized on a case-by-case basis. Future studies should focus on alternative imaging methods and/or contract agents.

Pregnancy in acromegaly is safe and is associated with improvements in IGF-1 concentrations

Pregnancy is rarely reported in acromegaly. Many patients are diagnosed in later life and younger patients may have subfertility due to hypopituitarism. We present a case series of 17 pregnancies in 12 women with acromegaly. Twelve women with acromegaly who completed pregnancy were identified from centres involved in the Irish Pituitary Study. Eleven women had pituitary macroadenomas and one woman had a microadenoma. Only 5/17 pregnancies had optimal biochemical control of acromegaly preconception, as defined by IGF-1 concentration in the age-related reference level and plasma GH concentration of <2 μg/L. In 6/17 pregnancies, dopamine agonist treatment was continued during pregnancy; all other acromegaly treatments were discontinued during pregnancy. Effect of pregnancy on acromegaly: No patient developed new visual field abnormalities, or symptoms suggestive of tumour expansion during pregnancy. In 9/12 patients, plasma IGF-1 concentrations that were elevated preconception normalised during pregnancy. There was a reduction in plasma IGF-1 concentrations, though not into the normal range, in a further two pregnancies. Effect of acromegaly on pregnancy: 15 healthy babies were born at term; one patient underwent emergency C-section at 32 weeks for pre-eclampsia, and one twin pregnancy had an elective C-section at 35 weeks' gestation. Blood pressure remained within normal limits in the remainder of the pregnancies. Gestational diabetes did not develop in any pregnancy. Our data suggests that pregnancy in women with acromegaly is generally safe, from a maternal and foetal perspective. Furthermore, biochemical control tends to improve despite the withdrawal of somatostatin analogue therapy during pregnancy.

An update on clinical care for pregnant women with acromegaly

INTRODUCTION

As pregnancy is rare in women with acromegaly, only case reports and few series have been published.

AREAS COVERED

All case reports and publications dealing with pregnancy in patients with acromegaly were collated. Information concerning the effects of acromegaly on pregnancy outcomes, the impact of pregnancy on GH/IGF-I measurements, acromegaly comorbidity and pituitary adenoma size, the effects of treatment of acromegaly on fetus outcomes were retrieved and analyzed.

EXPERT COMMENTARY

Based on the small number of reported cases, pregnancy is generally uneventful, except for a potential increased incidence of gestational hypertension and diabetes mellitus. Medical therapy of acromegaly (dopamine agonists, somatostatin analogs, growth hormone-receptor antagonists) is generally interrupted before or at diagnosis of pregnancy. In very rare patients with a pituitary adenoma, particularly a macroadenoma that has not been surgically treated before pregnancy, or if a surgical remnant persists, or when acromegaly is revealed during pregnancy, tumor volume may increase and cause symptoms through a mass effect. Close monitoring of clinical manifestations and imaging are necessary during pregnancy in these cases. In the rare cases of symptomatic tumor enlargement during pregnancy, medical treatment with dopamine agonists or eventually somatostatin analogs may be attempted before resorting to transsphenoidal surgery.

Ept7, a quantitative trait locus that controls estrogen-induced pituitary lactotroph hyperplasia in rat, is orthologous to a locus in humans that has been associated with numerous cancer types and common diseases

Pituitary adenoma is a common intracranial neoplasm that is observed in approximately 10% of unselected individuals at autopsy. Prolactin-producing adenomas, i.e., prolactinomas, comprise approximately 50% of all pituitary adenomas and represent the most common class of pituitary tumor. Multiple observations suggest that estrogens may contribute to development of prolactinoma; however, direct evidence for a causal role of estrogens in prolactinoma etiology is lacking. Rat models of estrogen-induced prolactinoma have been utilized extensively to identify the factors, pathways and processes that are involved in pituitary tumor development. The objective of this study was to localize to high resolution Ept7 (Estrogen-induced pituitary tumor), a quantitative trait locus (QTL) that controls lactotroph responsiveness to estrogens and was mapped to rat chromosome 7 (RNO7) in an intercross between BN and ACI rats. Data presented and discussed herein localize the Ept7 causal variant(s) to a 1.91 Mb interval of RNO7 that contains two protein coding genes, A1bg and Myc, and Pvt1, which yields multiple non-protein coding transcripts of unknown function. The Ept7 orthologous region in humans is located at 8q24.21 and has been linked in genome wide association studies to risk of 8 distinct epithelial cancers, including breast, ovarian, and endometrial cancers; 3 distinct types of B cell lymphoma; multiple inflammatory and autoimmune diseases; and orofacial cleft defects. In addition, the Ept7 locus in humans has been associated with variation in normal hematologic and development phenotypes, including height. Functional characterization of Ept7 should ultimately enhance our understanding of the genetic etiology of prolactinoma and these other diseases.

Outcome of pregnancies in a large cohort of women with acromegaly

OBJECTIVE

To assess the outcome of pregnancies in a large cohort of women with acromegaly.

DESIGN AND METHODS

This is a retrospective analysis of 31 pregnancies in 20 patients with acromegaly.

RESULTS

Twenty-seven pregnancies resulted in healthy offspring, and 4 resulted in abortion. Three patients underwent transsphenoidal surgery during pregnancy. IGF-1 levels remained elevated during pregnancy in 4 pregnancies and normalized in 23 cases. Fifteen cases were followed during pregnancy without any medical or surgical treatment, and 13 of these exhibited normal IGF-1 levels. Before or during pregnancy, somatostatin receptor ligands usage was not associated with higher risk for adverse outcomes. Arterial hypertension worsening (45%) and impairment of glucose levels (32%) were the most common complications during pregnancies. There were no maternal or neonatal deaths. One woman delivered twins. Two cases of congenital malformations and one with foetal macrosomia were observed. Caesarean delivery was performed in sixteen cases.

CONCLUSION

Our study confirms the impact of gestation on IGF-1 levels. However, it also indicates that acromegaly still holds an increased risk for worsening of comorbidities, especially in uncontrolled patients.

How does pregnancy affect the patients with pituitary adenomas: a study on 113 pregnancies from Turkey

OBJECTIVE

Data regarding pregnancies in relation to pituitary tumors are limited. The effects of pregnancy on pituitary adenomas and the effects of adenoma itself (hormonal activity, mass effects and pituitary insufficiency) and/or treatment on the ongoing gestation and developing fetus were evaluated.

METHODS

The study was a retrospective study. A questionnaire involving questions regarding medical history before index gestation, history of related pregnancy, result of index gestation and postpartum follow-up of the patients was filled by the investigator in one of the eight Referral Endocrinology Centers from Turkey.

RESULTS

One hundred and thirteen (83 prolactinoma, 21 acromegaly, 8 NFPA and 1 plurihormonal pituitary adenoma) pregnancies of 87 (60 prolactinoma, 19 acromegaly, 7 NFPA and 1 plurihormonal pituitary adenoma) patients were reviewed. The clinically important pregnancy-related tumor growth of pituitary adenomas was found to be low in previously treated adenomas. Prolactinomas were more likely to increase in size during pregnancy especially if effective prior treatment was lacking. The risk of hypopituitarism is also minimal due to pituitary adenomas during pregnancy. The results of pregnancies did not differ in patients who were on medical treatment or not for prolactinomas and acromegaly during gestation. Neural tube defect and microcephaly associated with maternal cabergoline use; Down syndrome and corpus callosum agenesis associated with maternal bromocriptine use; unilateral congenital cataract, craniosynostosis and microcephaly associated with maternal acromegaly were detected for the first time.

CONCLUSION

Medical treatment can be safely done stopped in patients with prolactinoma and acromegaly when pregnancy is confirmed and reinstituted when necessary. Prospective studies may help to determine the effects of medical treatment during gestation on the mother and fetus.

Pregnancy promotes pituitary tumors by increasing the rate of the cell cycle

Pituitary tumors may secrete hormones that affect pregnancy. Pregnancy also induces pituitary tumor growth; however, how pregnancy increases the growth of pituitary tumors remains unclear. The present study investigated pregnant female mice with subcutaneous pituitary tumors. The time of tumor occurrence and tumor weight were detected in pregnant and control mice. Tumor weights were measured at the end of the experiment. Blood was collected from pregnant and control mice. Brain-derived neurotrophic factor (BDNF) levels in the blood were detected using an ELISA kit. The in vitro effects of BDNF on pituitary tumor AtT-20 cell proliferation and cell cycle were investigated. It was revealed that pregnancy promoted the growth of pituitary tumors. In comparison to non-pregnant mice, the pregnant mice exhibited increased BDNF levels in the blood. In vitro BDNF treatment was able to increase the rate of proliferation of pituitary tumor cells. Additional cell cycle analysis revealed that BDNF was able to alter the cell cycle distribution of pituitary tumor cells. These results indicated that pregnancy was able to increase the BDNF level and promote the growth of pituitary tumor cells by increasing the rate of the cell cycle, leading to increased tumor growth rate in vivo. The present study provides insights into how pregnancy affects the growth of pituitary tumors. Therefore, it may be beneficial to perform pituitary tumor diagnosis or therapy on pregnant patients.

Sheehan's syndrome: new insights into an old disease

Sheehan's syndrome (SS) is a parturition-related pituitary disease resulting from severe postpartum hemorrhage and can present with varying degrees of pituitary insufficiency. Pathological and clinical findings of SS were first described by Harold L. Sheehan in the previous century. Although his definitions are still valid, various studies and reports including new data have subsequently been published. Additionally, the diagnosis of SS has often been overlooked and thus delayed for long years due to its nonspecific signs and symptoms. Therefore, a large number of patients may be remained undiagnosed and untreated. SS is not as rare as assumed in developed countries, probably due to migrant women and unawareness of physicians regarding the syndrome. In this review, we provide a detailed review of the epidemiology, etiopathogenesis, clinical, laboratory and radiological features, new diagnostic criteria, differential diagnosis, and treatment of SS.

Pregnancy in acromegaly patients treated with pegvisomant

To summarize all available data on pregnancy outcome of acromegaly patients exposed to the growth hormone receptor antagonist pegvisomant (PEGV) during pregnancy as present in the Pfizer's Global Safety Database. Pfizer's Global Safety Database contains adverse event data obtained from the following sources: spontaneous reports, health authorities, Pfizer-sponsored post-marketing surveillance program (ACROSTUDY), customer engagement programs, and clinical studies, reported regardless of outcome. The safety database was searched up to 10th March 2014. From the 35 pregnancy cases, 27 involved maternal [mean age (range) 33.3 years (23-41) and 8 paternal (33.7 years (32-38)] PEGV exposure. Two female patients were reported with two pregnancy cases each. Fetal outcome was normal in 14 (4 paternal) of the 18 reported as live birth, while 4 cases (1 paternal) did not specify the birth outcome. At conception, PEGV mean dose (range) was 15.3 mg/d (4.3-30). In 3 cases of maternal exposure of the 18 cases reporting live birth, PEGV was continued throughout the pregnancy in a dose of 12.1 mg/d (10-15). In 5 cases (all maternal) an elective termination of the pregnancy was performed with no reported fetal abnormalities, 2 cases (maternal) reported a non-PEGV-related spontaneous abortion and in 1 maternal case an ectopic pregnancy occurred. In 9 cases (3 paternal), the fetal outcome was not reported. Three women reported gestational diabetes; one woman continued PEGV treatment during pregnancy. Although the number of reported pregnancies with exposure to PEGV is very small, the presented data reflect the largest series of data available to date and do not suggest adverse consequences of PEGV on pregnancy outcome. Nevertheless, it should be stressed that PEGV should not be used during pregnancy unless absolutely necessary.

The effects of bromocriptine on preventing postpartum flare in systemic lupus erythematosus patients from South China

Objective. Prolactin plays an important role on the disease flare of postpartum SLE patients. 76 pregnant SLE patients were enrolled in this study to evaluate the efficacy of bromocriptine (an inhibitor of prolactin secretion) on preventing the postpartum disease relapse. Methods. Patients were randomly divided into the treatment group (bromocriptine, 2.5 mg oral, twice a day for 14 days after delivery) and the control group. All the patients were followed up for 12 months. Clinical features were recorded every 4 weeks. Serum prolactin and estradiol levels were measured at the second week and the second month after delivery. The endpoint of the study was disease relapse and defined when SLEDAI score increased by ≥3 points from the antenatal baseline. Results. (1) Serum levels of prolactin and estradiol decreased significantly in bromocriptine treatment group at the second week (P < 0.001) and second month (P < 0.05) after delivery compared to control group. (2) The relapse rate of the treatment group was lower than the control group (χ² = 4.68, P = 0.0305). Conclusions. Two weeks of oral bromocriptine treatment in postpartum SLE patients may relieve the disease from hyperprolactinemia and hyperestrogenemia and may be beneficial in preventing the patients from disease relapse.

Pituitary disorders in pregnancy

The pituitary gland is significantly affected during gestation in terms of both size and function. Due to this physiologic adaptation, endocrine evaluation and interpretation of imaging is far more complex than in the non-pregnant state. Pituitary disorders are rare in pregnancy, as they are usually associated with gonadal dysfunction, thereby posing difficulties with fertility. This review will focus on pituitary adenomas (prolactinomas, GH-secreting and ACTH-secreting), their diagnostic handicaps and the recommendations for treatment. We will also discuss the two pituitary disorders encountered in pregnancy, Sheehan's syndrome and lymphocytic hypophysitis.

Pituitary tumors and pregnancy: the interplay between a pathologic condition and a physiologic status

Pregnancy is becoming a relatively common event in patients with pituitary tumors (PT), due to the increasing availability of medical treatments, which control pituitary diseases associated with the development of PT. However, the presence of PT and its treatment may be a disturbing factor for pregnancy, and pregnancy significantly influences the course and the management of PT. This review summarizes the knowledge about the management of PT during pregnancy and the occurrence of pregnancy in patients with pre-existent PT, focusing on secreting PT characterized by hormonal excess and on clinically non-functioning PT often associated to hormone deficiency, which configure the hypopituitaric syndrome.

Hyperprolactinemia and prolactinoma

Prolactinomas are the most frequent pituitary adenomas. In patients with prolactinomas the primary cause of hyperprolactinemia is excessive and autonomic production of prolactin by lactotroph cells. In other conditions, except in case of macroprolactinemia, hyperprolactinemia is secondary to circumstances that stimulate secretion of prolactin by intrinsically normal lactotroph cells, or, rarely, that are the result of decreased clearance of prolactin. In general, cabergoline is the preferred treatment for micro- and macroprolactinomas, because it is more effective with respect to normalization of prolactin levels and reduction of prolactinoma size and because it has fewer side-effects compared to bromocriptine. Recently, it has been suggested that a standardized, individualized, stepwise, dose-escalating regimen of cabergoline may normalize prolactin levels and reduce prolactinoma size in patients who were otherwise considered to be dopamine agonist resistant. In general, the cardiac adverse effects of dopamine agonists reported in Parkinson's disease are not of clinical concern in the treatment of prolactinomas, which are treated with much lower doses. Nonetheless, there is uncertainty with respect to the dose and duration of cabergoline treatment, which requires echocardiographic follow-up. Although withdrawal of dopamine agonists may be considered in patients with prolactinomas well controlled by dopamine agonists, especially in postmenopausal women, recurrence of signs and symptoms may occur in a considerable portion of patients.

Pregnancy and acromegaly: a review

To review the literature regarding the diagnosis and management of acromegaly during pregnancy. A systematic literature search was performed using MEDLINE including hand-searching reference lists from original articles. The diagnosis of acromegaly during pregnancy is made difficult due to the physiologic changes in pituitary GH secretion and IGF-1 production resulting from placental GH secretion and the inability of commercial assays to discriminate between pituitary and placental GH. Most patients with acromegaly during pregnancy do not have an increase in tumor size, metabolic complications are uncommon, and neonatal outcome is largely unaffected. IGF-1 levels tend to be stable in such patients possibly due to the high estrogen levels causing GH resistance. Dopamine agonists, somatostatin analogues, and a GH receptor antagonist have been reported to be safe during pregnancy. Patients with visual field defects should be considered for surgery, but in most cases this can be safely postponed until after delivery. Overall, pregnancy in acromegaly is uneventful and newborns unaffected. Dopamine agonists and somatostatin analogues have not been associated with major adverse effects to the fetus; however, more data are needed to validate their safety.

Management of pituitary tumors in pregnancy

Pituitary tumors, usually adenomas, account for about 10-15% of all intracranial tumors. Their treatment, which includes surgery, medicine or radiotherapy, either isolated or in combination, aims to halt tumor growth or achieve tumor shrinkage, as well as control hormone hypersecretion or ensure hormone replacement. Such approaches have made pregnancy possible for women with pituitary adenomas. Medical therapy with dopamine agonists is the treatment of choice for most patients with prolactinomas, with surgery reserved for individuals resistant to drugs. On the other hand, surgery before conception is indicated as a first-line approach in patients with acromegaly, Cushing disease or clinically nonfunctioning pituitary macroadenomas. In these patient populations, medical therapy with somatostatin analogues (acromegaly) or drugs that target the adrenal glands, such as metyrapone and ketoconazole (Cushing disease), should be reserved for those in whom surgery is unsuccessful or contraindicated.

A radiologic score to distinguish autoimmune hypophysitis from nonsecreting pituitary adenoma preoperatively

BACKGROUND AND PURPOSE

Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery.

MATERIALS AND METHODS

This was a case-control study of 402 patients, which compared the presurgical pituitary MR imaging features of patients with nonsecreting pituitary adenoma and controls with AH. MR images were compared on the basis of 16 morphologic features besides sex, age, and relation to pregnancy.

RESULTS

Only 2 of the 19 proposed features tested lacked prognostic value. When the other 17 predictors were analyzed jointly in a multiple logistic regression model, 8 (relation to pregnancy, pituitary mass volume and symmetry, signal intensity and signal intensity homogeneity after gadolinium administration, posterior pituitary bright spot presence, stalk size, and mucosal swelling) remained significant predictors of a correct classification. The diagnostic score had a global performance of 0.9917 and correctly classified 97% of the patients, with a sensitivity of 92%, a specificity of 99%, a positive predictive value of 97%, and a negative predictive value of 97% for the diagnosis of AH.

CONCLUSIONS

This new radiologic score could be integrated into the management of patients with AH, who derive greater benefit from medical as opposed to surgical treatment.

Pituitary tumours: the prolactinoma

This review focus on the epidemiology, diagnosis and treatment of prolactinomas. In particular, attention was given to recent data showing a high prevalence of these tumours in the general population, 3-5 times higher than previously reported. The diagnosis of hyperprolactinaemia has been simplified in recent years, and only prolactin (PRL) assay and magnetic resonance imaging of the sella are required. Nonetheless, macroprolactinaemia should be assessed in patients with hyperprolactinaemia in the absence of clinical symptoms of elevated PRL levels. The recent evidence that medical therapy with dopamine agonists should be continued lifelong has been confirmed by several studied. The patients achieving disappearance of the tumours and suppression of PRL levels during treatment are those showing the highest likelihood to have persistent remission of hyperprolactinaemia after treatment withdrawal.

[Cushing's syndrome: special issues]

The present article reviews: Corticotrophin (ACTH) independent bilateral macronodular adrenal hyperplasia, which is characterized by aberrant adrenal receptors due to either ectopic expression or to overexpression (eutopic expression). Micronodular adrenal hyperplasia, which provokes small pigmented nodules in the adrenal gland with atrophy of the internodal tissue. These nodules may not be visible on imaging tests. The term subclinical Cushing's syndrome, coined in 1981, should be used in patients with clinically non-functioning adrenal adenomas but who show autonomous cortisol production that is insufficient to generate overt Cushing's syndrome. This entity must be distinguished from preclinical Cushing's syndrome, given that the subclinical form does not necessarily herald the development of symptoms of hypercortisolism. Cushing's syndrome is uncommon in children and adolescents. Regarding the general incidence of the disease, only 10% of cases are diagnosed in this age group. The most common cause of endogenous Cushing's disease in children older than 7 years is ACTH-dependent Cushing's disease (85%). The association of Cushing's syndrome and pregnancy is highly uncommon, since hypercortisolism usually causes amenorrhea, oligomenorrhea and infertility due to inhibition of gonadotropin secretion. One hundred thirty-six pregnancies have been described in 122 women, with a gestational age at diagnosis of 18.4+/-1 weeks.

Clinical practice guideline for hypotalamic-pituitary disturbances in pregnancy and the postpartum period

During pregnancy, the body undergoes a major adaptation process as a result of the interaction between mother, placenta and fetus. Major anatomical and histological changes are produced in the pituitary, with an increase of up to 40% in the size of the gland. There are wide variations in the function of the hypothalamus-pituitary-thyroid axis that effect iodine balance, the overall activity of the gland, as well as transport of thyroid hormones in plasma and peripheral metabolism of thyroid hormones. The incidence of goiter and thyroid nodules increases throughout pregnancy. The management of differentiated thyroid carcinoma should be individually tailored according to tumoral type and pregnancy stage. Given the effects of hypothyroidism on fetal development, both the diagnosis and appropriate therapeutic management of thyroid hypofunction are essential. The most important modification to the hypothalamus-pituitary-adrenal axis during pregnancy is the rise in serum cortisol levels due to an increase in cortisol-binding proteins. Although Cushing's syndrome during pregnancy is infrequent, both diagnosis and treatment of this disorder are especially difficult. Adrenal insufficiency during pregnancy does not substantially differ from that occurring outside pregnancy. However, postpartum pituitary necrosis (Sheehan's syndrome) is a well-known complication that occurs after delivery and, together with lymphocytic hypophysitis, constitutes the most frequent cause of adrenal insufficiency. The management of prolactinoma during pregnancy requires suppression of dopaminergic agonists and their reintroduction if there is tumoral growth. Notable among the neuropituitary disorders that can occur throughout pregnancy is diabetes insipidus, which occurs as a consequence of increased vasopressinase activity.

Hyperprolactinemia and prolactinomas

Any process interfering with dopamine synthesis, its transport to the pituitary gland, or its action at the level of lactotroph dopamine receptors can cause hyperprolactinemia. As described in this article, considering the complexity of prolactin regulation, many factors could cause hyperprolactinemia, and hyperprolactinemia can have clinical effects not only on the reproductive axis. Once any drug effects are excluded, prolactinomas are the most common cause of hyperprolactinemia. The most frequent symptom is hypogonadism in both genders. Medical and surgical therapies generally have excellent results, and most prolactinomas are well controlled or even cured in some cases.

Drugs and prolactin

Medications commonly cause hyperprolactinemia and their use must be differentiated from pathologic causes. The most common medications to cause hyperprolactinemia are the antipsychotic agents, although some of the newer atypical antipsychotics do not do so. Other medications causing hyperprolactinemia include antidepressants, antihypertensive agents, and drugs which increase bowel motility. Often, the medication-induced hyperprolactinemia is symptomatic, causing galactorrhea, menstrual disturbance, and erectile dysfunction. In the individual patient, it is important differentiate hyperprolactinemia due to a medication from a structural lesion in the hypothalamic-pituitary area. This can be done by stopping the medication temporarily to determine if the prolactin (PRL) levels return to normal, switching to another medication in the same class which does not cause hyperprolactinemia (in consultation with the patient's physician and/or psychiatrist), or by performing an MRI or CT scan. If the hyperprolactinemia is symptomatic, management strategies include switching to an alternative medication which does not cause hyperprolactinemia, using estrogen/testosterone replacement, or cautiously adding a dopamine agonist.

Imaging of Neurologic Disorders Associated with Pregnancy and the Postpartum Period

Diverse pathologic conditions affect the central nervous system (CNS) and pituitary gland during pregnancy and the puerperium. Some are specific to the physiologic process of reproduction (eg, eclampsia, postpartum cerebral angiopathy, Sheehan syndrome, lymphocytic adenohypophysitis). Others are nonspecific but occur more often in pregnant women (eg, cerebral infarction, dural venous thrombosis, pituitary apoplexy). Recognition of the characteristic imaging findings in eclampsia, for example, may allow exclusion of other disorders. Even when imaging changes are nonspecific, knowledge of those entities associated with pregnancy and awareness of the increased likelihood of certain diseases in pregnancy will allow a more informed differential diagnosis. Differentiation of primary nonaneurysmal subarachnoid hemorrhage (SAH) from aneurysmal SAH is an example. Moreover, earlier use of imaging will result in fewer delayed diagnoses. For example, magnetic resonance venography allows early diagnosis of cerebral venous thrombosis. Even when the imaging changes are less specific, knowledge of likely possibilities will lead to more appropriate earlier use of imaging. For example, the stimulatory effects of pregnancy on prolactinoma, meningioma, hemangioblastoma, vestibular schwannoma, and metastatic tumors such as breast cancer and choriocarcinoma suggest the early use of CNS imaging to avoid the consequences of a delayed diagnosis.

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future.