Pituitary tumors in childhood

Outcome of Dopamine Agonist Therapy Withdrawal in Children with Prolactinomas

BACKGROUND

Prolactinomas are rare in children and adolescents. As in adults, dopamine agonists (DAs) are the treatment of choice in the majority of patients. However, at what point children should be taken off of therapy and what the recurrence risk of hyperprolactinemia is following treatment withdrawal is not well described.

OBJECTIVE

Our objective was to systematically review our experience with DA treatment withdrawal in children and adolescents with prolactinomas.

METHODS

A retrospective review of patients followed for prolactinomas during the last 12 years was conducted. Variables analyzed included age, gender, initial serum prolactin levels, tumor characteristics, cabergoline dose, and results of treatment withdrawal. Clinical characteristics of patients who met eligibility criteria for DA withdrawal were compared with those who did not. Patients who underwent surgery were excluded.

RESULTS

Of 47 patients identified, 42 were included in the study. Of those, DA withdrawal was attempted in 13 (31%) and was initially successful in 3 (21%). Patients who did not meet eligibility criteria for treatment withdrawal had higher baseline prolactin levels (p = 0.018) as well as larger (p = 0.03) and more invasive (p = 0.002) tumors.

CONCLUSIONS

Less than half of our patients were eligible for DA treatment withdrawal and less than one-fourth achieved remission of hyperprolactinemia following cessation of therapy. This suggests that the overall recurrence rate of prolactinomas in pediatric patients may be higher than has been reported in adults.

Current Advances in the Management of Adult Craniopharyngiomas

Craniopharyngiomas (CPs) are slow growing, histologically benign intracranial tumors located in the sellar–suprasellar region. Although known to have low mortality, their location and relationship to the adjacent neural structures results in patients having significant neurologic, endocrine, and visual comorbidities. The invasive nature of this tumor makes complete resection a challenge and contributes to its recurrence. Additionally, these tumors are bimodally distributed, being treated with surgery, and are followed by other adjuncts, such as focused radiation therapy, e.g., Gamma knife. Advances in surgical techniques, imaging tools, and instrumentations have resulted in the evolution of surgery using endoscopic techniques, with residual components being treated by radiotherapy to target the residual tumor. Advances in molecular biology have elucidated the main pathways involved in tumor development and recurrence, but presently, no other treatments are offered to patients, besides surgery, radiation, and endocrine management, as the disease and tumor evolve. We review the contemporary management of these tumors, from the evolution of surgical treatments, utilizing standard open microscopic approaches to the more recent endoscopic surgery, and discuss the current recommendations for care of these patients. We discuss the developments in radiation therapy, such as radiosurgery, being used as treatment strategies for craniopharyngioma, highlighting their beneficial effects on tumor resections while decreasing the rates of adverse outcomes. We also outline the recent chemotherapy modalities, which help control tumor growth, and the immune landscape on craniopharyngiomas that allow the development of novel immunotherapies.

Clinical Approach to Sodium Homeostasis Disorders in Children with Pituitary-Suprasellar Tumors

Children with pituitary-suprasellar tumors are at high risk of developing sodium metabolism disorders since the tumoral mass itself or surgical and medical treatment can damage AVP release circuits. Additional risk factors are represented by the use of hypotonic fluids, the young age, total parenteral nutrition, and obstructive hydrocephalus secondary to tumor pathology. The most frequent hyponatremic disorders related to AVP in these patients are the syndrome of inappropriate ADH secretion and the cerebral/renal salt wasting syndrome, while hypernatremic conditions include central diabetes insipidus (CDI) and adipsic CDI. The main challenge in the management of these patients is to promptly distinguish the AVP release disorder at the base of the sodium imbalance and treat it correctly by avoiding rapid sodium fluctuations. These disorders can coexist or follow each other in a few hours or days; therefore, careful clinical and biochemical monitoring is necessary, especially during surgery, the use of chemotherapeutic agents, or radiotherapy. This monitoring should be performed by experienced healthcare professionals and should be multidisciplinary, including pediatric endocrinologists, neurosurgeons, and oncologists since maintaining sodium homeostasis also plays a prognostic role in terms of disease survival, therapeutic response, hospitalization rate, and mortality. In this review, we analyze the management of sodium homeostasis disorders in children with pituitary-suprasellar tumors and discuss the main challenges in the diagnosis and treatment of these conditions based on literature data and over 30 years of clinical experience at our Department of Pediatric Endocrinology.

Pediatric pituitary adenomas

BACKGROUND

Pediatric pituitary adenomas are a rare medical entity that makes up a small portion of intracranial tumors in children and adolescents. Although benign, the majority of these lesions are secreting functional tumors with the potential for physiological sequela that can profoundly affect a child's development.

FOCUS OF REVIEW

In this review, we discuss the medical and surgical management of these tumors with a focus on clinical presentation, diagnostic identification, surgical approach, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to treat these tumors. The management of pituitary tumors requires a multidisciplinary team of surgeons, endocrinologists, and neuroanesthesiologists as well as neurocritical care specialists to deliver comprehensive care.

Pediatric craniopharyngioma

BACKGROUND

Craniopharyngioma has historically been recognized to be a formidable pathology primarily due to its proximity to critical neurovascular structures and the challenging surgical corridors that surgeons have tried to reach this lesion.

FOCUS OF REVIEW

In this work, we review the medical and surgical management of these tumors with a focus on clinical presentation, diagnostic identification, surgical approach, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to craniopharyngiomas. The management of craniopharyngiomas requires a multidisciplinary team of surgeons, endocrinologists, and neuroanesthesiologists as well as neurocritical care specialists to deliver the most comprehensive and safest surgical resection with minimal postoperative morbidity.

Pediatric pituitary adenomas in Northeast Mexico. A follow-up study

PURPOSE

To review incidence, treatment and outcome of pediatric pituitary adenomas (PAs).

METHODS

A follow-up study patients with the age of ≤19 years old who were treated from 1995 to 2015 in Mexico.

RESULTS

Out of 1244 diagnosed PA, 43 patients were children (35 females, 8 males) with a mean age of 17.2 years. The majority were macroadenomas (70%) with prolactinomas (PRL) dominating (63%) followed by non-functioning adenomas (21%). In total, 40% were diagnosed as invasive. Growth hormone (GH) secreting adenomas, adrenocorticotropic hormone secreting and mixed GH-PRL secreting were rare. The treatment modalities were dopamine agonists and surgery. The average treatment time was 44 months with an average follow-up period of 104 months. Sixty-eight percent (27/40) of the patients had complete response after long time follow-up. Thirty-one percent did not respond to treatment whereof three patients died due to advanced disease and late intervention. The principal causes for treatment failure were treatment resistance, late intervention and poor patient compliance.

CONCLUSIONS

Sixty eight percent had complete treatment response without any sign of disease, while ~31% did not respond to treatment or did not comply to follow up/treatment. Optimized early diagnose, treatment methods with early intervention, long time follow-up and with better measures for patient compliance should improve outcomes.

Beneficial Effects of High Doses of Cabergoline in the Treatment of Giant Prolactinoma Resistant to Dopamine Agonists: A Case Report with a 21-Year Follow-Up

INTRODUCTION

Prolactinomas are pituitary tumors with a very low prevalence in childhood and adolescence compared to adulthood. This condition is preferentially treated with dopamine agonists. Resistance to these drugs is rare.

CASE REPORT

We describe the case of a boy diagnosed with macroadenoma at the age of 9 and followed up for 21 years. He did not fully respond to treatment with dopamine agonists. His initial prolactin level was 2,400 ng/mL (in males, normal values are <16.0 ng/mL) and never normalized. At the last assessment, his prolactin level was 21.5 ng/mL, recorded after 21 years of treatment with the dopamine agonist cabergoline at a dose as high as 4.5 mg per week. Although the prolactin level remained elevated throughout the follow-up period, the patient never presented a low testosterone level and had normal pubertal development. An MRI of the sella turcica showed that the tumor became progressively cystic and disappeared, but a normal pituitary gland was observed. The pituitary gland retained its normal functions despite a partially empty sella.

DISCUSSION

Long-term treatment with high doses of cabergoline may cause cystic degeneration of a prolactinoma considered to be resistant to this treatment, but we cannot rule out the possibility that this outcome represents the natural development of the tumor.

Management and consequences of postoperative fluctuations in plasma sodium concentration after pediatric brain tumor surgery in the sellar region: a national cohort analysis

PURPOSE

Severe fluctuations in plasma sodium concentration and plasma osmolarity, including central diabetes insipidus (CDI), may have significant influence on postoperative morbidity and mortality after pediatric brain tumor surgery.The aim of this study was to describe the frequency, severity and neurological consequences of these fluctuations in pediatric brain tumor survivors.

METHODS

A retrospective, multi-institutional chart review was conducted among all children who underwent brain tumor surgery in the sellar or suprasellar region in seven university hospitals in the Netherlands between January 2004 and December 2013.

RESULTS

Postoperative CDI was observed in 67.5% of 120 included children. Fluctuations of plasma sodium concentration ≥ 10 mmol/L/24 h during the first ten postoperative days were seen in 75.3% of patients with CDI, with a maximum delta of 46 mmol/L/24 h. When compared to patients without CDI, altered mental status occurred more frequently in patients with postoperative CDI (5.1 vs. 23.5% respectively, p = 0.009). Low plasma sodium concentration was related to altered mental status and the occurrence of seizures. Frequency and severity of fluctuations in plasma sodium concentration during the first ten postoperative days were significantly higher in patients with permanent CDI at last follow-up than in patients with transient CDI or without CDI (p = 0.007).

CONCLUSION

Postoperative CDI is a common complication after pediatric brain tumor surgery in the sellar or suprasellar region. Extreme plasma sodium concentrations and large intra-day fluctuations still occur and seem to influence the postoperative neurological course. These results illustrate the need for intensive monitoring in a highly experienced center.

Imaging of the Sella and Parasellar Region in the Pediatric Population

Masses in the sella and parasellar region comprise about 10% of all pediatric brain tumors but type and frequency differs from those in adults. Imaging is critical for diagnosis and characterization of these lesions. By assessing the site of origin, signal and contrast enhancement characteristics, and the presence or absence of characteristic patterns, differential diagnosis can narrow the possibilities. The clinical presentation is often characteristic for lesion type and should be considered. This article summarizes the characteristic imaging features of the most frequent pediatric tumors and tumor-mimicking lesions in children in this region.

Neurological Complications of Endocrine Disease

The endocrine system is a complex group of organs and glands that relates to multiple other organs and systems in the body with the ultimate goal of maintaining homeostasis. This complex network functions through hormones excreted by several glands and released in the blood, targeting different body tissues and modulating their function. Any primary disorders affecting the endocrine glands and altering the amount of hormones synthesized and released will lead to disruption in the functions of multiple organs. The central nervous system of a developing child is particularly sensitive to endocrine disorders. A variety of neurological manifestations have been described as features of several endocrine diseases in childhood. Their knowledge may contribute to an early diagnosis of a particular endocrine condition, especially when more typical features are not present yet. In this article, we discuss specific neurological manifestations found in various endocrine disorders in children.

Treatment-resistant pediatric giant prolactinoma and multiple endocrine neoplasia type 1

Background

Pediatric pituitary adenomas are rare, accounting for <3 % of all childhood intracranial tumors, the majority of which are prolactinomas. Consequently, they are often misdiagnosed as other suprasellar masses such as craniopharyngiomas in this age group. Whilst guidelines exist for the treatment of adult prolactinomas, the management of childhood presentations of these benign tumors is less clear, particularly when dopamine agonist therapy fails. Given their rarity, childhood-onset pituitary adenomas are more likely to be associated with a variety of genetic syndromes, the commonest being multiple endocrine neoplasia type 1 (MEN-1).

Case description

We present a case of an early-onset, treatment-resistant giant prolactinoma occurring in an 11-year-old peripubertal boy that was initially sensitive, but subsequently highly resistant to dopamine agonist therapy, ultimately requiring multiple surgical debulking procedures and proton beam irradiation. Our patient is now left with long-term tumor- and treatment-related neuroendocrine morbidities including blindness and panhypopituitarism. Only after multiple consultations and clinical data gained from 20-year-old medical records was a complex, intergenerationally consanguineous family history revealed, compatible with MEN-1, with a splice site mutation (c.784-9G > A) being eventually identified in intron 4 of the MEN1 gene, potentially explaining the difficulties in management of this tumor. Genetic counseling and screening has now been offered to the wider family.

Conclusions

This case emphasizes the need to consider pituitary adenomas in the differential diagnosis of all pediatric suprasellar tumors by careful endocrine assessment and measurement of at least a serum prolactin concentration. It also highlights the lack of evidence for the optimal management of pediatric drug-resistant prolactinomas. Finally, the case we describe demonstrates the importance of a detailed family history and the role of genetic testing for MEN1 and AIP mutations in all cases of pediatric pituitary adenoma.

Prolactinomas in children under 14. Clinical presentation and long-term follow-up

PURPOSE

Pediatric prolactinomas are rare, especially in children under 14 years of age. In this study, we evaluated the clinical presentation and microsurgical outcome of prolactinomas in prepubertal children.

METHODS

Nine patients with prolactinomas who had undergone surgical removal of the tumor before the age of 14 years were included in this retrospective study. Data on their clinical presentation, medications, physical and laboratory evaluations, radiological findings, and long-time follow-up were obtained from their medical records.

RESULTS

The main presenting symptom in the four female patients was galactorrhea (n = 4, 100%), whereas the five male patients most commonly presented with headache (n = 4, 80%) and growth retardation (n = 3, 60%). Six (66.6%) of the patients who had undergone transsphenoidal surgery were medication-free postoperatively. In three (33.3%) patients with giant adenomas, complete resection of the tumor was not achieved. One (11.1%) patient received radiotherapy after failed surgical and medical treatment. Postoperatively, electrolyte disturbances occurred in five (55.6%) patients, diabetes insipidus in two (22.2%), and thyroid dysfunction in two (22.2%). These complications resolved spontaneously. During follow-up, growth and puberty were usually normal.

CONCLUSIONS

Tumor compressive symptoms and/or gonadal and growth arrest may be the primary clinical presentations of pediatric prolactinoma. Patients who are not candidates for dopamine agonist therapy are best treated surgically, based on the low mortality and high cure rates. Hypopituitarism is a rare complication and may resolve spontaneously. Following successful treatment of a prolactinoma, growth and puberty in these children are normal.

Transnasal Transsphenoidal Surgical Method in Pediatric Pituitary Adenomas

AIM

To evaluate the clinical outcome in a 13-year consecutive series of children operated for pituitary adenomas with transnasal transsphenoidal surgery.

METHODS

All patients <18 years who were operated on at our center by transsphenoidal surgery for pediatric pituitary adenomas were included in the study. Clinical features, hormonal profile, radiology, surgical approach, results and complications were analyzed.

RESULTS

Eighteen patients (90%) had functional pituitary adenomas and 2 (10%) patients had nonfunctional pituitary adenoma. The most common type was prolactin-secreting adenoma (n = 12), followed by corticotropinoma (n = 4), growth hormone-secreting adenoma (n = 2), and nonfunctioning adenoma (n = 2). Prolactin-secreting adenomas in children occurred more commonly with suprasellar expansion than did other adenomas.

CONCLUSION

Transsphenoidal surgery was effective for decompression of suprasellar extension and relieved the chiasmal compression immediately. Prolactin-secreting tumors required postoperative medical therapy for persistently elevated prolactin levels.