Contemporary management of prolactinomas

Outcomes and surgical nuances in management of giant pituitary adenomas: a review of 108 cases in the endoscopic era

OBJECTIVE

Giant (maximum diameter ≥ 4 cm) pituitary macroadenomas are complex tumors that require resection for decompression of optic nerves, relief of mass effect, and symptom improvement. Given the lack of surgical accessibility, the lateral extent of the lesions, and the invasion of the cavernous sinus, management presents a significant challenge. Transsphenoidal, transcranial, and combined approaches have been viable options for resection. The authors present their findings from a large series of patients to characterize giant pituitary adenomas, document outcomes, and outline surgical nuances in resection of these tumors.

METHODS

The authors reviewed 887 consecutive patients who underwent resection of pituitary adenomas at a single institution. From this group, 108 patients with giant pituitary adenomas who underwent resection between January 1, 2002, and December 31, 2020, were identified for inclusion in the study. The patient demographics, clinical presentation, tumor imaging characteristics, surgical approaches, and postoperative outcomes were analyzed using descriptive statistics.

RESULTS

The mean preoperative tumor diameter in this cohort was 4.6 ± 0.8 cm, with a mean volume of 25.9 ± 19.2 cm3. Ninety-seven patients underwent transsphenoidal approaches only, 3 underwent transcranial resection, and 8 patients underwent a combined approach. Gross-total resection was achieved in 42 patients. Tumor stability without a need for additional therapy was achieved in 77 patients, with 26 patients undergoing subsequent adjuvant radiotherapy. Among 100 patients with sufficient follow-up, 14 underwent adjuvant therapy-repeat operation and/or adjuvant radiation therapy-because of recurrence or tumor progression. Six patients with recurrence were observed without additional treatment. Overall, the morbidity associated with removal of these lesions was 11.1%; the most common morbidities were cerebrospinal fluid leak (5 patients, 4.6%) and hydrocephalus (4 patients, 3.7%). One death due to postoperative pituitary apoplexy of the residual tumor and malignant cerebral edema occurred in this cohort.

CONCLUSIONS

Giant pituitary tumors still represent a surgical challenge, with significant morbidity. Gross-total resection occurs in a minority of patients. Surgical goals for removal of giant pituitary tumors should include attempts at removal of most tumor tissue to minimize the risk of residual tumor apoplexy by tailoring the approach along the major axis of the tumor. Experience with both transsphenoidal and multiple transcranial techniques is necessary for minimizing complications and improving outcomes.

Aggressive giant prolactinoma: a case report

BACKGROUND

Managing treatment-resistant aggressive giant prolactinoma can be challenging, as the diagnosis is often complex, and treatment beyond dopamine agonists, surgery, and radiotherapy is limited.

CASE PRESENTATION

A 21-year-old Malay woman first presented to our hospital at the age of 16 years with 1-year history of reduced vision and 2 years of amenorrhea. Her baseline prolactin level was 255,894 µIU/mL with secondary hypogonadism, and pituitary magnetic resonance imaging revealed a giant prolactinoma (2.8 × 3.2 × 4.2 cm³) with suprasellar extension and optic chiasmal compression. She was initially treated with cabergoline, and reductions in the prolactin level and tumor mass were achieved, leading to vision improvement and resumption of normal menstruation. However, she developed recurrent tumor growth and hyperprolactinemia, causing relapse of symptoms, and she needed surgery. Eventually, despite three tumor debulking surgeries and escalation of cabergoline doses up to 1 mg/day, her tumor progressed with aggressive characteristics. Following a multidisciplinary meeting, the patient is initiated on temozolomide therapy after considering the long-term side effects of radiotherapy in her case.

CONCLUSION

This case highlights the importance of early identification of treatment-resistant prolactinoma and the need for a multidisciplinary approach in managing aggressive prolactinoma in young patients, particularly regarding timely implementation of temozolomide therapy.

Primary Endoscopic Endonasal Management of Giant Pituitary Adenomas: Outcome and Pitfalls from a Large Prospective Multicenter Experience

Simple Summary

Giant pituitary adenomas are highly invasive tumors whose treatment is challenging. Surgery is their management mainstay. However, there is no consensus about the type of approach. Open transcranial, microscopic, and endoscopic trans-sphenoidal approaches have all been employed, alone or in combination. Extended endoscopic endonasal techniques may represent a versatile and safe one-stage approach. Our research aimed at evaluating prospectively their applicability, effectiveness, and safety in a multicenter series, to acquire further evidence toward its use in the treatment of those challenging lesions. Ninety-six patients were recruited and followed-up for 52.4 months on average. Most of them (81.2%) presented with visual deficits and >50% had various degrees of adenohypophysis insufficiency. Resection of at least 75% of initial volume was achieved in all cases, with 98.7% visual improvement, >50% endocrine deficit recovery and a permanent complication rate of 4.2%, indicating extended endoscopic endonasal approaches as a valuable treatment option.

Abstract

Purpose: To evaluate factors influencing clinical and radiological outcome of extended endoscopic endonasal transtuberculum/transplanum approach (EEA-TTP) for giant pituitary adenomas (GPAs). Methods: We recruited prospectively all consecutive GPAs patients undergoing EEA-TTP between 2015 and 2019 in 5 neurosurgical centers. Preoperative clinical and radiologic features, visual and hormonal outcomes, extent of resection (EoR), complications and recurrence rates were recorded and analyzed. Results: Of 1169 patients treated for pituitary adenoma, 96 (8.2%) had GPAs. Seventy-eight (81.2%) patients had visual impairment, 12 (12.5%) had headaches, 3 (3.1%) had drowsiness due to hydrocephalus, and 53 (55.2%) had anterior pituitary insufficiency. EoR was gross or near-total in 46 (47.9%) and subtotal in 50 (52.1%) patients. Incomplete resection was associated with lateral suprasellar, intraventricular and/or cavernous sinus extension and with firm/fibrous consistence. At the last follow-up, all but one patient (77, 98.7%) with visual deficits improved. Headache improved in 8 (88.9%) and anterior pituitary function recovered in 27 (50.9%) patients. Recurrence rate was 16.7%, with 32 months mean recurrence-free survival. Conclusions: EEA-TTP is a valid option for GPAs and seems to provide better outcomes, lower rate of complications and higher EoR compared to one- or multi-stage microscopic, non-extended endoscopic transsphenoidal, and transcranial resections.

Prolactinomas and nonfunctioning adenomas: preoperative diagnosis of tumor type using serum prolactin and tumor size

OBJECTIVE

Prolactinoma and nonfunctioning adenoma (NFA) are the most common sellar pathologies, and both can present with hyperprolactinemia. There are no definitive studies analyzing the relationship between the sizes of prolactinomas and NFAs and the serum prolactin level. Current guidelines for serum prolactin level cutoffs to distinguish between pathologies are suboptimal because they fail to consider the adenoma volume. In this study, the authors attempted to describe the relationship between serum prolactin level and prolactinoma volume. They also examined the predictive value that can be gained by considering tumor volume in differentiating prolactinoma from NFA and provide cutoff values based on a large sample of patients.

METHODS

A retrospective analysis of consecutive patients with prolactinomas (n = 76) and NFAs (n = 217) was performed. Patients were divided into groups based on adenoma volume, and the two pathologies were compared.

RESULTS

A strong correlation was found between prolactinoma volume and serum prolactin level (r = 0.831, p < 0.001). However, there was no significant correlation between NFA volume and serum prolactin level (r = -0.020, p = 0.773). Receiver operating characteristic curve analysis of three different adenoma volume groups was performed and resulted in different serum prolactin level cutoffs for each group. For group 1 (≤ 0.5 cm3), the most accurate cutoff was 43.65 μg/L (area under the curve [AUC] = 0.951); for group 2 (> 0.5 to 4 cm3), 60.05 μg/L (AUC = 0.949); and for group 3 (> 4 cm3), 248.15 μg/L (AUC = 1.0).

CONCLUSIONS

Prolactinoma volume has a significant impact on serum prolactin level, whereas NFA volume does not. This finding indicates that the amount of prolactin-producing tissue is a more important factor regarding serum prolactin level than absolute adenoma volume. Hence, volume should be a determining factor to distinguish between prolactinoma and NFA prior to surgery. Current serum prolactin threshold level guidelines are suboptimal and cannot be generalized across all adenoma volumes.

Endoscopic Transsphenoidal Surgery of Microprolactinomas: A Reappraisal of Cure Rate Based on Radiological Criteria

BACKGROUND

Current standard treatment of microprolactinomas is dopamine agonist therapy. As this drug treatment is lifelong in up to 80% of cases, many patients consult pituitary surgeons regarding a surgical alternative.

OBJECTIVE

To identify prognostic criteria for surgical remission, we reviewed outcomes of our series of microprolactinomas treated with endoscopic transsphenoidal surgery, with a special emphasis on magnetic resonance adenoma delineation and position.

METHODS

Our study cohort comprises a single center series of 60 patients operated for histopathologically verified magnetic resonance imaging unequivocally identifiable endosellar microprolactinoma between 2003 and 2017. In 31 patients the adenoma was enclosed by pituitary gland (group ENC), in 29 patients the adenoma was located lateral to the gland adherent to the medial cavernous sinus wall (group LAT).

RESULTS

After a mean follow-up of 37 mo (range 4-143 mo), remission rate was significantly higher in adenomas enclosed by pituitary gland (group ENC) than adenomas located lateral to the gland (group LAT), with 87% vs 45%, P = .01. Intraoperatively, 4 patients showed signs of invasiveness. Preoperative prolactin levels did not differ between the groups (mean 155 and 187 ng/ml in group ENC and LAT, respectively).A binary logistic regression model revealed that only the radiological criteria applied showed a significant correlation (P = .003) with endocrine remission.

CONCLUSION

According to our results, remission rate is significantly higher in microprolactinomas enclosed by the pituitary gland. However, the decision for surgery should take into account surgeons experience and possibility of complications.

Prolactinomas: Prognostic Factors of Early Remission After Transsphenoidal Surgery

Background and Objective: Most patients with prolactinomas receive pharmacological treatment only, resulting in limited research on the predictors of successful prolactinoma surgery. In this study, we analyzed whether early postoperative serum prolactin concentrations and selected tumor characteristics could predict early, hormonal remission after removal of prolactinomas. Methods: We prospectively enrolled 48 consecutive patients with prolactinomas who underwent transsphenoidal resection performed by the same surgeon. Early remission, defined as a lack of hyperprolactinemia symptoms and normalization of serum prolactin concentration, was ascertained in all patients at 3 months. We evaluated the invasiveness of prolactinomas on the Knosp grading scale and measured serum prolactin concentrations on the first postoperative day. Routine immunohistochemical analysis, evaluation for plurihormonality, and assessment of the Ki-67 proliferation index (<3 or ≥3% of positive nuclei) were performed in all tumor samples. Results: Of 48 patients, 38 (79%) achieved early biochemical remission at 3 months. Patients in early remission at 3 months had lower serum prolactin concentrations on the first postoperative day than patients with recurrent or persistent hyperprolactinemia (p < 0.001). Using univariate logistic regression, larger maximum tumor diameter (p = 0.014), higher Knosp grade (p < 0.001), and plurihormonality predicted remission at 3 months (p = 0.021). However, using multivariate stepwise logistic regression, only the Knosp grade remained significant (p < 0.001). Conclusions: Radiological assessment of prolactinoma invasiveness (Knosp grades) and early postoperative serum prolactin concentrations are important predictors of early remission following transsphenoidal prolactinoma resection.

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.

Metformin inhibits growth and prolactin secretion of pituitary prolactinoma cells and xenografts

Metformin (MET) is a diabetes drug that activates AMP-activated protein kinase (AMPK), and is suggested to have anticancer efficacy. Here, we investigated the role of AMPK signalling in prolactinoma (PRLoma), with particular respect to MET and bromocriptine (BC) as a PRLoma treatment. We analysed AMPK phosphorylation, dopamine D2 receptor (D2R), and oestrogen receptor (ER) expression in both BC-sensitive and -resistant PRLoma samples; effects of the AMPK agonist MET (alone or with BC) on in vitro proliferation and apoptosis, xenograft growth and prolactin (PRL) secretion of BC-sensitive and -resistant cells, and ER expression in xenografts. Some BC-resistant PRLomas showed high D2R expression but extremely low AMPK activation. MET significantly inhibited proliferation of cultured PRLoma cells; MET + BC notably restrained their PRL secretion. MET + BC further decreased tumour growth and serum PRL levels in xenografts than BC treatment alone. ER was down-regulated after AMPK activation in both cultured cells and xenografts. Together, we propose that the AMPK signalling pathway down-regulates ERα and ERβ, and suppresses PRLoma growth as well as PRL secretion. Combined MET + BC is a potential treatment for PRLomas.

Clinical outcomes in male patients with lactotroph adenomas who required pituitary surgery: a retrospective single center study

PURPOSE

Lactotroph adenomas (LA) are the most frequently encountered pituitary tumors. Although more frequently observed in women, LAs in men were recently included in a more aggressive category regardless of histological grading, by the WHO. We aimed to perform a rigorous retrospective review of a single center's pre-operative evaluation, patient characteristics and outcomes of male LAs patients requiring pituitary surgery.

METHODS

A retrospective review, over 11 years, of patients who underwent resection of a pituitary adenoma at a single center was conducted. Predictors of persistent disease in male LAs patients along with a comparison to predictors of silent corticotroph adenomas (SCAs) patients who also underwent surgery at the center was also conducted.

RESULTS

Thirty-one male patients with LAs were identified. When compared to SCAs patients, LAs male patients were younger (41 vs. 50 years of age, p = 0.01). Men with LAs had more invasive tumors (75% vs. 44.7% p = 0.02). More LAs in men had residual tumor after surgery than patients with SCA (92.6% vs. 42.1%, p < 0.001). Male patients with LAs and patients with SCA had similar rates of requiring additional surgery (28.9% vs. 24.1%, p = NS) and radiation therapy (18.4% vs. 19.4%, p = NS).

CONCLUSIONS

High rates of DA resistance, invasive tumors and postoperative residual disease in male patients with LA who required surgery are shown. Surgery improved optic chiasm compression, PRL level and central hypogonadism but, not surprisingly, failed to normalize other pituitary hormones and/or eliminate need for DA therapy.

[Modern Management of Pituitary Adenomas - Current State of Diagnosis, Treatment and Follow-Up]

Modern Management of Pituitary Adenomas - Current State of Diagnosis, Treatment and Follow-Up Abstract. Pituitary adenomas (PA) are benign neoplasms originating from parenchymal cells of the anterior pituitary. Tumor mass effect can cause headaches, visual deficits by compression of the optic chiasm, and partial or complete hypopituitarism. Hormone secreting PA can cause several forms of specific syndromes such as Cushing's disease or acromegaly depending on the type of hormone. Endoscopic transsphenoidal resection is the preferred treatment option for most symptomatic or growing PA. Nowadays techniques like high definition intraoperative MRI can assist the surgeon in his goal of maximal safe resection. An exception are prolactinomas which can usually be treated medically with dopamine agonists. Therapy of PA is complex and should be managed in a high-volume center with an interdisciplinary team approach including neurosurgeons and endocrinologists.

Pediatric Pituitary Adenoma: Case Series, Review of the Literature, and a Skull Base Treatment Paradigm

Background  Pediatric pituitary adenoma is a rare skull base neoplasm, accounting for 3% of all intracranial neoplasms in children and 5% of pituitary adenomas. Compared with pituitary tumors in adults, secreting tumors predominate and longer disease trajectories are expected due to the patient age resulting in a natural history and treatment paradigm that is complex and controversial. Objectives  The aims of this study were to describe a large, single-institution series of pediatric pituitary adenomas with extensive long-term follow-up and to conduct a systematic review examining outcomes after pituitary adenoma surgery in the pediatric population. Methods  The study cohort was compiled by searching institutional pathology and operative reports using diagnosis and site codes for pituitary and sellar pathology, from 1956 to 2016. Systematic review of the English language literature since 1970 was conducted using PubMed, MEDLINE, Embase, and Google Scholar. Results  Thirty-nine surgically managed pediatric pituitary adenomas were identified, including 15 prolactinomas, 14 corticotrophs, 7 somatotrophs, and 4 non-secreting adenomas. All patients underwent transsphenoidal resection (TSR) as the initial surgical treatment. Surgical cure was achieved in 18 (46%); 21 experienced recurrent/persistent disease, with secondary treatments including repeat surgery in 10, radiation in 14, adjuvant pharmacotherapy in 11, and bilateral adrenalectomy in 3. At the last follow-up (median 87 months, range 3-581), nine remained with recurrent/persistent disease (23%). Thirty-seven publications reporting surgical series of pediatric pituitary adenomas were included, containing 1,284 patients. Adrenocorticotropic hormone (ACTH)-secreting tumors were most prevalent (43%), followed by prolactin (PRL)-secreting (37%), growth hormone (GH)-secreting (12%), and nonsecreting (7%). Surgical cure was reported in 65%. Complications included pituitary insufficiency (23%), permanent visual dysfunction (6%), chronic diabetes insipidus (DI) (3%), and postoperative cerebrospinal fluid (CSF) leak (4%). Mean follow-up was 63 months (range 0-240), with recurrent/persistent disease reported in 18% at the time of last follow-up. Conclusion  Pediatric pituitary adenomas are diverse and challenging tumors with complexities far beyond those encountered in the management of routine adult pituitary disease, including nuanced decision-making, a technically demanding operative environment, high propensity for recurrence, and the potentially serious consequences of hypopituitarism with respect to fertility and growth potential in a pediatric population. Optimal treatment requires a high degree of individualization, and patients are most likely to benefit from consolidated, multidisciplinary care in highly experienced centers.

Medical versus surgical treatment of prolactinomas: an analysis of treatment outcomes

INTRODUCTION

Prolactinomas are unique tumors that may go into both hormonal and radiographic remission with dopamine agonist therapy or transsphenoidal surgery. Regardless of modality, the goals of therapy remain the same: (1) biochemical remission, including reduction of prolactin and normalization of sex hormones; (2) radiographic tumor control, with a range including prevention of tumor growth, tumor regression, or complete tumor resolution; (3) resolution of preoperative symptoms, including those that are hormonal or neurologic; and (4) prevention of new hypopituitarism or new neurologic symptoms.

AREAS COVERED

In the following review, we performed a search of the literature using keywords 'prolactinoma,' 'dopamine agonist,' 'surgery,' 'cost-effectiveness,' 'recurrence,' and 'complication' to compare the relative merits of medical versus surgical therapy for prolactinoma, including special circumstances such as cystic tumors, pregnant patients, and the cost-effectiveness of different strategies.

EXPERT COMMENTARY

Medical therapy can offer a cure, but surgery provides an important adjunct to patients with resistance or intolerance to dopamine agonists, and offers excellent outcomes including when combined with continued postoperative medical therapy. Further head to head comparisons will benefit patients and practitioners weighing the relative risks and benefits of medical and surgical intervention, including the issue of their relative cost-effectiveness.

Reoperative endoscopic endonasal surgery for residual or recurrent pituitary adenomas

OBJECTIVE

Regrowth of the lesion after surgical removal of pituitary adenomas is uncommon unless subtotal resection was originally achieved in the first surgery. Treatment for recurrent tumor can involve surgery or radiotherapy. Locations of residual tumor may vary based on the original approach. The authors evaluated the specific sites of residual or recurrent tumor after different transsphenoidal approaches and describe the surgical outcome of endoscopic endonasal transsphenoidal reoperation.

METHODS

The authors analyzed a prospectively collected database of a consecutive series of patients who had undergone endoscopic endonasal surgeries for residual or recurrent pituitary adenomas after an original transsphenoidal microscopic or endoscopic surgery. The site of the recurrent tumor and outcome after reoperation were noted and correlated with the primary surgical approach. The chi-square or Fisher exact test was used to compare categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between surgical groups.

RESULTS

Forty-one patients underwent surgery for residual/recurrent pituitary adenoma from 2004 to 2015 at Weill Cornell Medical College. The previous treatment was a transsphenoidal microscopic (n = 22) and endoscopic endonasal (n = 19) surgery. In 83.3% patients (n = 30/36) there was postoperative residual tumor after the initial surgery. A residual tumor following endonasal endoscopic surgery was less common in the sphenoid sinus (10.5%; 2/19) than it was after microscopic transsphenoidal surgery (72.7%; n =16/22; p = 0.004). Gross-total resection (GTR) was achieved in 58.5%, and either GTR or near-total resection was achieved in 92.7%. Across all cases, the average extent of resection was 93.7%. The rate of GTR was lower in patients with Knosp-Steiner Grade 3–4 invasion (p < 0.0005). Postoperative CSF leak was seen in only one case (2.4%), which stopped with lumbar drainage. Visual fields improved in 52.9% (n = 9/17) of patients and were stable in 47% (n = 8/17). Endocrine remission was achieved in 77.8% (n = 14/18) of cases, 12 by surgery alone and 2 by adjuvant medical (n = 1) and radiation (n = 1) therapy. New diabetes insipidus occurred in 4.9% (n = 2/41) of patients—in one of whom an additional single anterior hormonal axis was compromised—and 9.7% (n = 4/41) of patients had a new anterior pituitary hormonal insufficiency.

CONCLUSIONS

Endonasal endoscopic reoperation is extremely effective at removing recurrent or residual pituitary adenomas that remain after a prior surgery, and it may be preferable to radiation therapy particularly in symptomatic patients. Achievement of GTR is less common when lateral cavernous sinus invasion is present. The locations of residual/recurrent tumor were more likely sphenoidal and parasellar following a prior microscopic transsphenoidal surgery and sellar following a prior endonasal endoscopic surgery.

Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas

Background Few studies address the cost of treating prolactinomas. We performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings.

Update on prolactinomas. Part 1: Clinical manifestations and diagnostic challenges

The authors provide an update on the clinical manifestations and diagnostic challenges of prolactinomas. Prolactinomas are the most common pituitary adenoma seen in clinical practice. Secondary causes of hyperprolactinemia should be ruled out by assessment of the clinical history, including current medications, physical examination, pregnancy test, routine biochemical analysis with a thyroid function test, and neuroimaging, before a confirmatory diagnosis of prolactinoma is made. Prolactinomas are associated with endocrine dysfunction, affecting gonadal function and causing neurological deficits due to mass effect. The progress in elucidating the pathogenesis of prolactinomas and advances in diagnostic methods, including more sensitive diagnostic hormone assays and neuroimaging, have enriched the current diagnostic approach and management. Making the correct diagnosis is crucial to implementing the appropriate therapy. Dopamine agonist therapy remains the first line of treatment for prolactinomas, as it is effective in normalizing serum prolactin levels and reducing tumor size. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or for those experiencing progressive neurological deficits. Nevertheless, curative surgical resection as a primary mode of treatment for smaller prolactinomas has recently gained attention as an alternative to lifelong dopamine agonist treatment.

Cost-Effectiveness Analysis of Microscopic and Endoscopic Transsphenoidal Surgery Versus Medical Therapy in the Management of Microprolactinoma in the United States

BACKGROUND

Although prolactinomas are treated effectively with dopamine agonists, some have proposed curative surgical resection for select cases of microprolactinomas to avoid life-long medical therapy. We performed a cost-effectiveness analysis comparing transsphenoidal surgery (either microsurgical or endoscopic) and medical therapy (either bromocriptine or cabergoline) with decision analysis modeling.

METHODS

A 2-armed decision tree was created with TreeAge Pro Suite 2012 to compare upfront transsphenoidal surgery versus medical therapy. The economic perspective was that of the health care third-party payer. On the basis of a literature review, we assigned plausible distributions for costs and utilities to each potential outcome, taking into account medical and surgical costs and complications. Base-case analysis, sensitivity analysis, and Monte Carlo simulations were performed to determine the cost-effectiveness of each strategy at 5-year and 10-year time horizons.

RESULTS

In the base-case scenario, microscopic transsphenoidal surgery was the most cost-effective option at 5 years from the time of diagnosis; however, by the 10-year time horizon, endoscopic transsphenoidal surgery became the most cost-effective option. At both time horizons, medical therapy (both bromocriptine and cabergoline) were found to be more costly and less effective than transsphenoidal surgery (i.e., the medical arm was dominated by the surgical arm in this model). Two-way sensitivity analysis demonstrated that endoscopic resection would be the most cost-effective strategy if the cure rate from endoscopic surgery was greater than 90% and the complication rate was less than 1%. Monte Carlo simulation was performed for endoscopic surgery versus microscopic surgery at both time horizons. This analysis produced an incremental cost-effectiveness ratio of $80,235 per quality-adjusted life years at 5 years and $40,737 per quality-adjusted life years at 10 years, implying that with increasing time intervals, endoscopic transsphenoidal surgery is the more cost-effective treatment strategy.

CONCLUSIONS

On the basis of the results of our model, transsphenoidal surgical resection of microprolactinomas, either microsurgical or endoscopic, appears to be more cost-effective than life-long medical therapy in young patients with life expectancy greater than 10 years. We caution that surgical resection for microprolactinomas be performed only in select cases by experienced pituitary surgeons at high-volume centers with high biochemical cure rates and low complication rates.

Update on prolactinomas. Part 2: Treatment and management strategies

The authors present an update on the various treatment modalities and discuss management strategies for prolactinomas. Prolactinomas are the most common type of functional pituitary tumor. Effective hyperprolactinemia treatment is of great importance, due to its potential deleterious effects including infertility, gonadal dysfunction and osteoporosis. Dopamine agonist therapy is the first line of treatment for prolactinomas because of its effectiveness in normalizing serum prolactin levels and shrinking tumor size. Though withdrawal of dopamine agonist treatment is safe and may be implemented following certain recommendations, recurrence of disease after cessation of the drug occurs in a substantial proportion of patients. Concerns regarding the safety of dopamine agonists have been raised, but its safety profile remains high, allowing its use during pregnancy. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or are experiencing progressive tumor growth. Surgical resection can also be considered as a primary treatment for those with smaller focal tumors where a biochemical cure can be expected as an alternative to lifelong dopamine agonist treatment. Stereotactic radiosurgery also serves as an option for those refractory to medical and surgical therapy.

Retrospective comparison of cabergoline and bromocriptine effects in hyperprolactinemia: a single center experience

INTRODUCTION

Patients with hyperprolactinemia who require medical therapy are typically treated with dopamine agonists (DAs). In most cases, DAs normalize prolactin levels, control symptoms, and substantially decrease tumor size. Here, we aimed to compare the efficacy of cabergoline (CAB) and bromocriptine (BRC) in patients with hyperprolactinemia at a single center.

METHODS

Retrospective analysis of the clinical records of 498 patients with hyperprolactinemia [mean age 33.3 ± 10.8 years (range 16-66), 450 women, and 48 men] who had received either CAB (n = 450) or BRC (n = 48) was performed.

RESULTS

The mean age, gender distribution, and treatment duration were similar between the CAB and BRC groups (33.2 ± 11 vs. 34.1 ± 9.6 years, male/female 44/406 vs. 4/44, 18.7 ± 12.1 vs. 17.8 ± 6.0 months, respectively; p > 0.05 for all). Mean dosage was 1.5 ± 1.6 mg/week for CAB and 3.8 ± 2.7 mg/day for BRC. Baseline prolactin levels, frequency of galactorrhea, amenorrhea, oligomenorrhea, erectile dysfunction, infertility, and visual impairment were similar between the two groups, whereas the baseline tumor volume was higher in the CAB group. The prolactin normalization rate (87.4 vs. 41.4 %, p = 0.029) and tumor volume shrinkage (79.8 ± 39.1 vs. 54.1 ± 55.3 %, p = 0.015) were significantly higher in the CAB-treated patients than in the BRC-treated patients, while the tumor cure rates were similar. Symptom relief was higher in the CAB group than in the BRC group. More side effects were recorded in patients who took BRC (29.1 vs. 5.3 %, p < 0.001).

CONCLUSION

Our data revealed that CAB was more effective than BRC in controlling symptoms associated with hormone excess, normalizing serum prolactin levels, and shrinking prolactinomas.

Managing Prolactinomas during Pregnancy

Prolactinomas are the most prevalent functional benign pituitary tumors due to a pituitary micro- or macroadenoma. The majority of patients presents with infertility and gonadal dysfunction. A dopamine agonist (DA) (bromocriptine or cabergoline) is the treatment of choice that can normalize prolactin levels, reduce tumor size, and restore ovulation and fertility. Cabergoline generally preferred over bromocriptine because of its higher efficacy and tolerability. Managing prolactinomas during pregnancy may be challenging. During pregnancy, the pituitary gland undergoes global hyperplasia due to a progressive increase in serum estrogens level that may lead to increase of the tumor volume with potential mass effect and visual loss. The risk of tumor enlargement may occur in 3% of those with microadenomas, 32% in those with macroadenomas that were not previously operated on, and 4.8% of those with macroadenomas with prior ablative treatment. Though both drugs appear to be safe during pregnancy, the data on fetal exposure to DAs during pregnancy have been reported with bromocriptine far exceeds that of cabergoline with no association of increased risk of pregnancy loss and premature delivery. It is advisable to stop the use of DAs immediately once pregnancy is confirmed, except in the case of women with invasive macroprolactinomas or pressure symptoms. This review outlines the therapeutic approach to prolactinoma during pregnancy, with emphasis on the safety of available DA therapy.

Proptosis as the presenting sign of giant prolactinoma in a prepubertal boy: successful resolution of hydrocephalus by use of medical therapy

We report the case of a 13-year-old prepubertal boy who presented with a left-sided proptosis, bilateral papilloedema and hydrocephalus who was subsequently diagnosed with a giant prolactinoma invading the left orbit. He was commenced on dopamine receptor agonists in the form of quinagolide and cabergoline, and made an excellent response to medical therapy alone, with resolution of hydrocephalus, restoration of normal vision and a 98% reduction in serum prolactin. The rapid improvement achieved negated the requirement for surgery and this highlights the efficacy of the dopamine agonists in the management of giant prolactinomas, even in the presence of neurological symptoms.

Endoscopic endonasal compared with microscopic transsphenoidal and open transcranial resection of giant pituitary adenomas

Giant (>4 cm) pituitary macroadenomas often require surgery to decompress the optic nerves. Compared with traditional open or transsphenoidal microscopic methods, the extended endoscopic endonasal transsphenoidal approach offers the potential for aggressive resection via a minimal access corridor. We conducted a systematic review of the literature to further our understanding of the role of endoscopy in the management of these challenging lesions. MEDLINE search of the modern literature (1995-2010) to identify surgical series for pediatric and adult pituitary adenomas >4 cm in maximal diameter. Patient and tumor characteristics, resection, morbidity and visual outcome were compared by approach. Chi-square and Fisher's exact tests with post-hoc Bonferroni analysis were used for statistical analyses. Sixteen studies (478 patients) were included. Compared with the open cohort, the endoscopic cohort had higher rates of gross total resection (47.2% vs. 9.6%; P < 0.003) and improved visual outcome (91.1% vs. 45.7%; P < 0.003). The microscopic transsphenoidal cohort had lower rate of total resection and worse visual outcomes than the endoscopic group. There were no instances of postoperative CSF leak reported in the endoscopic group. The transcranial group had a higher rate perioperative mortality compared to the transsphenoidal group (P = 0.004). In select cases, the endoscopic endonasal approach is safe and effective for the treatment of giant pituitary adenomas, with the potential for gross total resection and improved visual outcome. CSF leak, which is a major limitation of the endonasal approach, may be avoided using meticulous multi-layer closure and vascularised nasoseptal flaps.

Prolactin in men's health and disease

PURPOSE OF REVIEW

To review physiology of prolactin (PRL), cause and managment of hyperprolactinemia, and discuss evolving diverse roles of PRL in men's health.

RECENT FINDINGS

Hyperprolactinemia can be physiologically found after sexual activities, exercise, lactation, during pregnancy, and after stressful venipuncture. Elevated PRL can be caused by medications use, renal failure, hypothyroidism, and by prolactinoma - PRL secreting tumors. Symptomatic hyperprolactinemia and prolactinomas should be treated to lower PRL levels, decrease tumor size, and restore gonadal function. Three modes of treatment are typically utilized: pharmacological, radiosurgery with gamma radiation, and external beam radiation. Pharmacological treatment of prolactinomas is mainly based on dopamine agonists. The most frequently used dopamine agonists are bromocriptine and cabergoline. Cabergoline becoming the preferred drug in the treatment of prolactinomas because of higher response rate and less side-effects. Bromocriptine has been recently approved to improve glycemic control in diabetes mellitus.

SUMMARY

PRL plays a diverse role in men's reproduction and health. Detecting and treating elevated PRL may not only improve infertility and hypogonadism but also have a positive effect on the metabolic profile of patient and control of glycemic control and metabolic profile - an important advantage considering dramatic and worldwide increase in obesity and diabetes.

Gamma knife radiosurgery for patients with prolactin-secreting pituitary adenomas

OBJECTIVE

To evaluate the efficacy of stereotactic radiosurgery (SRS) for patients with prolactin (PRL)-secreting pituitary adenomas that were refractory to medical management.

METHODS

Retrospective review of 22 patients treated with SRS from 1994 until 2006. All patients were either intolerant or their tumors were unresponsive to dopamine agonist therapy. Nine patients (41%) had undergone prior transsphenoidal surgery. The median serum PRL concentration before SRS was 88.4 ng/mL (range, 25-943). The median treatment volume was 2.2 cm(3) (range, 0.4-29.0); the median margin radiation dose was 25 Gy (range, 16-30). The median endocrinologic follow-up was 60 months (range, 16-129).

RESULTS

Tumor control after SRS was 100%. Serum PRL concentration was significantly lower (median, 28.4 ng/mL) (P = 0.006) at last follow-up, but the 4-year actuarial rate of biochemical remission off medications was only 17%. No tested variable was associated with biochemical remission off medications. Overall, four patients (18%) had biochemical remission off medications and clinical improvement, three patients (14%) had normal serum PRL concentrations and clinical improvement on dopamine agonist therapy, seven patients (32%) had improved symptoms off medications but continued to have elevated serum PRL levels, and eight patients (36%) continued to be symptomatic with elevated PRL levels either on (n = 3) or off (n = 5) dopamine agonist therapy. The incidence of new anterior pituitary deficits was 42% at 4 years.

CONCLUSIONS

SRS was effective in controlling tumor growth for patients with PRL-secreting pituitary adenomas, and the majority of patients were clinically improved.

Clinical Problem Solving: Monster on the Hook—Case Problems in Neurosurgery

BACKGROUND AND OBJECTIVE:

Nonfunctioning and functioning pituitary tumors can present in numerous ways. They may be difficult to diagnose correctly and, even with proper treatment, may lead to complications.

METHODS:

We present the case of a patient who presented with a large, invasive sellar mass and underwent both medical and surgical treatment for this lesion. The patient's course did not progress as was expected from his initial workup.

RESULTS:

The patient's history, physical examination, laboratory values, pathologic specimens, and radiologic findings are discussed. His management before, during, and after medical therapy and surgery is reviewed by pituitary experts from 2 different institutions. Aspects of diagnosis and management of sellar lesions are presented and reviewed in the literature.

CONCLUSION:

Neurosurgeons frequently treat patients with sellar lesions and should remember that despite modern laboratory, pathologic, and radiologic techniques, the diagnosis and treatment of these lesions is not always clear.

Transcranial approach to pituitary adenomas invading the cavernous sinus: A modification of the classical technique to be used in a low-technology environment

Objective:

Pituitary adenomas invading the cavernous sinus represent a therapeutic challenge. Those tumors have been traditionally treated with incomplete surgical removal, observation and/ or adjunctive medical therapy, and radiotherapy. In relatively recent years, some authors have suggested a main direct surgical approach to cavernous sinus (CS) with the aim of complete removal of the adenoma, either by a modified trans-sphenoidal route, using or not an endoscopy-assisted approach, or by a transcranial direct approach. The latter has the advantage of allowing direct exposure of the lesion with a view of the surgical field unhindered by important neurovascular structures.

Materials and Methods:

We report a technical modification of the classical epidural approach for CS adenoma removal. This was used in 14 patients. Surgical technique included a fronto-orbito-zygomatic craniotomy with extradural anterior clinoidectomy, and intradural approach to the Hakuba’s triangle for intracavernous dissection. The tumors were removed under direct vision.

Results:

Total macroscopical removal was achieved in all but one case. This patient required postoperative radiation therapy as well as adjuvant dopaminergic regime for achieving control of preoperatively increased hormonal values. No other case required radiotherapy. Hormonal and/ or clinical control was also achieved in all the remaining cases. Out of the remaining 13 cases, all appeared to be tumor free at an average postoperative observation at 78 months (34 to 90 months). Significant surgical sequels were detected in only 1 case (persistent 3^rd nerve palsy and moderate hemiparesis).

Conclusions:

This experience, though limited, would suggest that the transcranial limited CS exposure through the Hakuba’s triangle may allow adequate removal of intracavernous pituitary adenomas with very good long-term results and acceptable complication rate.

Endoscopic endonasal transsphenoidal approach for pituitary adenomas invading the cavernous sinus

Object

In this report, the authors describe their experience with surgical access to the cavernous sinus via a fully transnasal endoscopic approach in 20 cases. Clinical and endocrinological follow-up are discussed.

Methods

The authors used an endoscopic transsphenoidal approach in 192 patients with pituitary adenomas between September 1997 and January 2008, adding a cavernous sinus approach in 20 patients with invasive tumors during the last 5 years of this period. Parasellar extension of the tumor was measured according to the Knosp Scale. Radical tumor removal was achieved in 13 (65%) of 20 patients, and subtotal removal in 7 (35%). The authors used recently defined cavernous sinus approaches in the first 14 cases, including the paraseptal approach in 6, middle turbinectomy in 7, and contralateral middle turbinectomy in 1 case. Combined approaches rather than defined standard cavernous sinus approaches were used in 4 cases and an extended approach in 2.

Results

The tumors included nonsecretory adenomas in 5 cases (25%), growth hormone–secreting adenomas in 7 (35%), prolactin-secreting adenomas in 4 (20%), and adrenocorticotropic hormone–secreting adenomas in 4 cases (20%). Normal growth hormone and insulin-like growth factor 1 levels were achieved in 4 patients (57%) with growth hormone adenomas, and remission criteria were obtained in 3 patients with prolactinomas and 3 patients with adrenocorticotropic hormone–secreting adenomas.

Conclusions

Compared with transcranial and microscopic transsphenoidal surgery, endoscopic transsphenoidal surgery offers a wide exposure for cavernous sinus medial wall adenomas that enables removal of the adenoma from the medial cavernous sinus wall. Because of the necessity for multidisciplinary treatment to achieve satisfactory results, Gamma Knife surgery and medical therapy should be supplementary treatment options after endoscopic transsphenoidal surgery.

Insidious extension of pituitary prolactinoma: two can't-miss findings depicted on a 3.0-T MR system

BACKGROUND

In this article, we present two can't-miss findings on preoperative magnetic resonance imaging (MRI) using a 3.0-T MR system resulting in a better surgical option in prolactinoma treatment after emergent of dopamine agonists.

METHODS

We reviewed six cases of pituitary prolactinoma; each had vague or occult bulk of adenoma on 1.5-T MR imaging, which were finally confirmed by surgery. Four cases were preoperatively examined with a 3.0-T MR imaging system. With the 3.0-T MR system, 3-dimension-anisotropy-contrast (3DAC) MR imaging and 3-dimension fast spoiled gradient recalled acquisition in the steady state (3D-FSPGR) imaging were used for depiction of the adenoma.

RESULTS

3DAC imaging revealed cavernous sinus (CS) pathology in three cases, and multiplanar reconstruction of 3D-FSPGR imaging revealed normal pituitary gland and invasive adenoma into the CS in three cases and creeping extension up to the contralateral side of the CS invasion in four cases.

CONCLUSIONS

Two can't-miss findings: (1) intrasellar creeping extension up to the opposite side of the adenoma main body and (2) intracavernous-localized adenoma with indistinct intrasellar mass should be carefully considered when neurosurgeons perform adenomectomy for patients with prolactinoma, even in cases of microprolactinoma.

Intrasellar symptomatic salivary gland rest

Ectopic salivary gland tissue in sellar turcica is frequently observed in microscopic examination at autopsy. This tissue is considered clinically silent. Only 2 symptomatic cases have been previously reported. Here we report a 28-year-old woman presenting with galactorrhea and hyperprolactinemia. Magnetic resonance imaging revealed a 6 x 5-mm nodule in the posterior aspect of the pituitary gland. This nodule showed isointensity on T1- and T2-weighted images and less enhancement on post-contrast T1-weighted images. Transsphenoidal exploration revealed a cystic lesion within the pituitary gland, which consisted of a grayish gelatinous content. The pathologic examination confirmed the diagnosis of salivary gland rest.

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.

Pituitary apoplexy in the magnetic resonance imaging era: clinical significance of sphenoid sinus mucosal thickening

OBJECT

The authors report their experience with pituitary apoplexy and evaluate the clinical significance of sphenoid sinus mucosal thickening found on magnetic resonance (MR) imaging.

METHODS

The cases of 28 patients (19 males and nine females) with pituitary apoplexy were reviewed retrospectively. The mean age of the patients was 50 years (range 16-83 years), and the mean follow-up duration was 32 months (range 1-104 months). Admission MR imaging demonstrated hemorrhage or infarction in a pituitary tumor in each patient. A clinical grading scale for apoplexy was devised as follows: Grade I, presence of acute headache and/or endocrine abnormality (12 patients); Grade II, presence of the foregoing symptoms as well as cranial nerve deficit (visual and/or oculomotor; 15 patients); and Grade III, presence of all of these symptoms and a decreased level of consciousness (one patient). Twenty-five patients (89%) underwent early transsphenoidal resection within 9 days (80% within 72 hours) of diagnosis. Headaches and oculomotor paresis resolved completely in 100%, visual function resolved completely in 44% and partially in 56%, and hypopituitarism was reversed in 25%. Twelve patients (43%) required long-term hormone replacement therapy. Two of the three patients who were treated conservatively had prolactin-secreting adenomas, which were treated with dopamine agonist therapy. Thickening of sphenoid sinus mucosa was present in 22 patients (79%). Fifty percent of patients in Grade I and 100% of those in Grades II and III, including all those with persistent hypopituitarism and residual visual deficits, had thickened sphenoid sinus mucosa on MR imaging. Patients with thickened sphenoid sinus mucosa had larger tumors that compressed the optic chiasm or cavernous sinus, and these individuals also had a higher rate of cranial nerve deficits at presentation than those without mucosal thickening (73% compared with 0%). Patients with thickened mucosa had a higher rate of hypopituitarism and subsequent long-term hormone replacement therapy than those without thickened mucosa (55% compared with 17%).

CONCLUSIONS

Thickened sphenoid sinus mucosa may correlate with higher grades of pituitary apoplexy and worse neurological and endocrinological outcomes.