Management of macroprolactinomas

Prolactin-secreting pituitary adenomas: male-specific differences in pathogenesis, clinical presentation and treatment

Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents. Therefore, the management of PRLomas in men is challenging in many cases. Additionally, hyperprolactinemia is associated with a significant negative impact on men's health, including sexual function and fertility potential, bone health, cardiovascular and metabolic complications, leading to decreased quality of life. In this review, we highlight the differences in pathogenesis, clinical presentation and treatment of PRLomas concerning the male sex.

Long-term Follow-up of 84 Patients With Giant Prolactinomas-A Swedish Nationwide Study

PURPOSE

To describe the clinical presentation and treatment outcomes in a nationwide cohort of patients with giant prolactinomas.

METHODS

Register-based study of patients with giant prolactinomas [serum prolactin (PRL) > 1000 µg/L, tumor diameter ≥40 mm] identified in the Swedish Pituitary Register 1991-2018.

RESULTS

Eighty-four patients [mean age 47 (SD ±16) years, 89% men] were included in the study. At diagnosis, the median PRL was 6305 µg/L (range 1450-253 000), the median tumor diameter was 47 mm (range 40-85), 84% of the patients had hypogonadotropic hypogonadism, and 71% visual field defects. All patients were treated with a dopamine agonist (DA) at some point. Twenty-three (27%) received 1 or more additional therapies, including surgery (n = 19), radiotherapy (n = 6), other medical treatments (n = 4), and chemotherapy (n = 2). Ki-67 was ≥10% in 4/14 tumors. At the last follow-up [median 9 years (interquartile range (IQR) 4-15)], the median PRL was 12 µg/L (IQR 4-126), and the median tumor diameter was 22 mm (IQR 3-40). Normalized PRL was achieved in 55%, significant tumor reduction in 69%, and combined response (normalized PRL and significant tumor reduction) in 43%. In the primary DA-treated patients (n = 79), the reduction in PRL or tumor size after the first year predicted the combined response at the last follow-up (P < .001 and P = .012, respectively).

CONCLUSION

DAs effectively reduced PRL and tumor size, but approximately 1 patient out of 4 needed multimodal treatment. Our results suggest that the response to DA after 1 year is useful for identifying patients who need more careful monitoring and, in some cases, additional treatment.

Prolactinoma: Clinical Characteristics, Management and Outcome

Aim Prolactinoma, a prolactin (PRL) secreting functioning pituitary tumor, is the most common of all pituitary adenomas (PA) accounting for 40-60% and dopamine agonists (DA) are the cornerstone of treatment. The aim of this study was to review the clinical presentation, treatment modalities and therapeutic outcomes of patients with prolactinomas in the South Asia region. Methods This retrospective study was conducted in the Endocrinology Department of Shaukat Khanum Memorial Cancer Hospital and Research Centre from December 2011 till December 2019. Medical records were used to retrieve for patient's demographics, clinical features at diagnosis, PRL levels and size of prolactinoma on MRI at diagnosis and after start of dopamine agonists and outcome of medical management. Results A total of 107 patients were included in this study. Mean age at diagnosis was 35 (22-54) years for men and 32 (18-50) years for women and 66.4% (71) of the patients were females. Our study included 38 (35.5%) microadenoma, 50 (46.7%) macroadenoma and 19 (17.8%) giant adenomas. At presentation, the most common symptom among females was menstrual irregularity/amenorrhea seen in 73.2% of females and among males was visual disturbance (80.6%). A significant reduction in PRL levels was seen within six to 12 months of treatment. Mean PRL levels decreased from 3162.8 ng/ml to 1.52 ng/ml. A notable decrease in tumor size was seen with medical management, mean adenoma size decreased from 2.18 cm to 1.04 cm. With cabergoline (CAB) 83.3% biochemical cure was seen compared to bromocriptine (BRC) which has 60.4%. The radiological response rate in CAB and BRC groups was 65.45% and 60%, respectively. Complete resolution of adenoma was seen in 13 patients (nine were microadenoma, two macro and two giant adenomas). The prolactin level at diagnosis was positively correlated with maximum tumor diameter (r = 0.469, P = 0.001). Two patients developed cerebrospinal fluid (CSF) rhinorrhea and the defect was repaired in both patients. Median follow-up duration was 40 (12-288) months. Conclusion Clinical presentation and demographics of prolactinoma are the same in our region when compared to the rest of the world. Cabergoline is superior to bromocriptine in prolactin normalization and tumor shrinkage but still bromocriptine is being used in a significant number of patients in low-income countries as first-line due to its low cost.

Aggressive prolactinoma (Review)

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

Optimal testosterone level to improve symptoms of hypogonadism without causing dopa-testotoxicosis in male macroprolactinoma

BACKGROUND

Male prolactinoma treatment by dopamine agonists (DA) restores sexual function. However, excessive DA dose can lead to impulse control disorder.

OBJECTIVES

The aim of this retrospective study was to determine the level of testosterone that eliminates symptoms and provides fertility in male macroprolactinoma, without causing these adverse effects.

MATERIALS AND METHODS

Twenty-seven male patients with macroprolactinoma were included. There were 16 macro (≥1-2.8 cm), 7 large macro (≥2.9-3.9 cm) and 4 giant (≥4 cm) adenomas. Prolactin (PRL) and testosterone (T) levels were evaluated. A timeline was created to analyze improvement in symptoms of hypogonadism and infertility. Testosterone levels were compared with age-matched controls.

RESULTS

Mean PRL, basal tumor diameter and shrinkage were 2,846±3,415 ng/mL, 27.2±10.2 mm and 63.4%, respectively. Basal T levels were 1.6±1.0 ng/mL for patients and 4.4±1.5 ng/mL for controls (p<0.001). Mean T level in the asymptomatic period was significantly lower than in controls (3.2±0.4 ng/mL vs. 4.4±1.5 ng/mL, respectively; p=0.002), while mean PRL was 27.2 ng/ml. Fertility was achieved in 6 of the patients seeking fertility, and there was no difference in T level between these patients and controls (3.7±0.8 ng/mL and 4.4±1.5 ng/mL, respectively; p=0.14); when fertility was achieved, mean PRL was 26.9±23 ng/mL.

CONCLUSION

Patients should be carefully questioned regarding complaints at each consultation, and DA dose should not be increased unnecessarily, to avoid possible serious adverse effects.

Long-term response to cabergoline and multi-modal treatment in men with macroprolactinoma: Does size really matter?

OBJECTIVE

To study the outcome of men with macroprolactinoma following cabergoline treatment based on tumour size.

DESIGN

Retrospective cohort study.

METHODS

The study included 94 men, divided into three groups according to adenoma diameter: 10-19 mm (Group A, n = 36); 20-39 mm (Group B, n = 41); or ≥40 mm (Group C, giant prolactinomas, n = 17). Patients were followed for a mean of 7.5 years with sellar magnetic resonance imaging, visual fields and hormone measurements.

RESULTS

Mean baseline prolactin was 767, 2090 and 24,806 ng/ml in Groups A, B and C, respectively (p < .01). Prolactin suppression below three times the upper limit of normal (ULN) was achieved in 34 (94%; mean weekly cabergoline dose of 1.2 mg), 37 (90%; cabergoline dose, 2.1 mg) and 15 (88%; cabergoline dose, 2.8 mg) men (p = .31) in each group. After excluding patients who underwent surgery and radiotherapy, cabergoline suppressed prolactin below three times ULN in 32/35 (91%), 29/37 (78%) and 11/14 (79%) men in Groups A, B and C, respectively (p = .27). Visual deficits were observed in 5 (14%), 12 (29%) and 10 (59%) patients (p < .01); improvement was achieved in 5/5 (100%), 11/12 (92%) and 10/10 (100%) of men in Groups A, B and C. Low baseline testosterone was measured in 26 (72%), 39 (95%) and 17 (100%) patients in the three groups (p < .01). Following multi-modal treatment, hypogonadism persisted in 3 (8%), 5 (12%) and 2 (12%) men, respectively (p = .85).

CONCLUSION

Macroprolactinomas in men were controlled with cabergoline in 84% of cases, independent of tumour size. Pituitary surgery and adjuvant radiotherapy further improved long-term response to 91%.

Pituitary apoplexy of a giant prolactinoma during pregnancy

AIMS AND METHODS

Prolactinomas are a common cause of sexual dysfunction and infertility. We aimed, through this case report, to illustrate the difficulties of management of women with giant prolactinoma, especially in cases of desire of pregnancy.

RESULTS

A 30-year-old woman was referred to our department for secondary amenorrhea. Investigations showed a prolactin level of 5168 ng/mL and giant pituitary adenoma of 4 cm in diameter. Cytoreductive surgery was performed after failure to normalize prolactin levels during three years with medical treatment by cabergoline. After seven months, menstrual cycles have resumed, and after 13 months, the patient became pregnant. At 22nd week of gestation, she was admitted in our hospital for pituitary apoplexy. Medical treatment with bromocriptine was chosen. The vaginal premature delivery at 28 weeks gave birth to twins weighing 1 Kg each who died on the 7th day of life.

CONCLUSION

This is a relevant clinical case that illustrates the efficacy of cytoreductive surgery in case of insufficient response to dopamine agonists to restore gonadal function. The possibility of a pregnancy should be considered in these patients since it can be associated with high maternal and fetal risks.

Educational Case: Pituitary Adenoma

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Spontaneous Cerebrospinal Fluid Rhinorrhea from a Prolactin-Secreting Pituitary Macroadenoma

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

Applying Telemedicine Technology in Treating Prolactinomas: A Case Report

Despite being considered a relatively new concept, telemedicine has already been associated with improved outcomes and reduced healthcare utilization in the management of several high-risk diseases. However, no reports to date have examined the effectiveness of telemedicine in managing prolactinomas. We report a case of a young male with a macroprolactinoma who was reviewed initially in a face-to-face encounter, however, continued his subsequent management virtually using telemedicine methods with satisfactory clinical outcomes.

Hyperprolactinaemia in the context of psychiatry

Advocating for good physical healthcare for their patients is of the utmost importance to psychiatrists. This narrative review focuses on one part of this large goal, the topic of hyperprolactinaemia from the perspective of mental healthcare. For psychiatrists this often includes managing raised prolactin levels in the context of medication. However, they must consider the wider differentials of a raised prolactin level and the possible impact of treatments. For that reason, in this review we start with an overview of prolactin physiology before considering hyperprolactinaemia both in the context of antipsychotic therapy and its wider differentials, including prolactinoma. Investigation and management are considered and key practice points developed.

Prolactinomas in males: any differences?

CONTEXT

Prolactinomas in men are usually large and invasive, presenting with signs and symptoms of hypogonadism and mass effects, including visual damage. Prolactin levels are high, associated with low testosterone, anemia, metabolic syndrome and if long-standing also osteoporosis.

RESULTS

Medical treatment with the dopamine agonist, cabergoline, became the preferred first-line treatment for male prolactinomas as well as for giant tumors, leading to prolactin normalization in ~ 80% of treated men, and tumor shrinkage, improved visual fields and recovery of hypogonadism in most patients. Multi-modal approach including surgery and occasionally radiotherapy together with a high-dose cabergoline is saved for resistant and invasive adenomas. Experimental treatments including temozolomide or pasireotide may improve clinical response in men harboring resistant prolactinomas.

CONCLUSIONS

Compared to other pituitary adenomas, secreting and non-secreting, where pituitary surgery is the recommended first-line treatment, men with prolactinomas will usually respond to medical treatment with no need for any additional treatment.

Unusual Course of an Aggressive Pituitary Prolactinoma: Case Report and Review of the Literature

Pituitary carcinomas are rare tumors with heterogeneous behaviors. Their carcinogenesis is still unknown. Consequently, treatment is multimodal and not standardized. Dopamine (DA) agonists are used as first-line treatments, while radiotherapy and surgery may be used for local control of invasive tumors. We describe the case of a 35-year-old male who presented with an invasive prolactinoma, managed initially with a transsphenoidal resection, postsurgical radiotherapy and DA agonists. The patient posteriorly presented a sole metastatic lesion to the lumbar spine that was later managed with local radiotherapy. Due to pituitary recurrence of the lesion, multiple surgical resections were needed until further treatment was declined. The clinical course in this patient was unusual. He lived for 13 years after initial diagnosis, with a very invasive tumor without systemic chemotherapy. Radiotherapy is used in pituitary tumors in which surgery fails; we hypothesize that it contributed to the malignant transformation and the late resistance to DA agonists in our patient. Several biomarkers in tumoral tissue have been evaluated regarding their association with malignancy and aggressive behaviors, although more studies are still needed. Therapeutic strategies are limited, without evidence on the impact on overall survival and prognosis. Risk factors associated with early malignancy in pituitary prolactinomas include recurrent behavior, increase in prolactin levels with a stable sellar mass, and secondary development of DA agonist resistance. However, there are still no conclusive answers as to whether physicians should rigorously follow up these patients or provide direct therapy with aggressive approaches.

Clinical management of difficult to treat macroprolactinomas

INTRODUCTION

Prolactinomas represent the most common pituitary adenomas encountered in the clinic. While a majority of these tumors will be successfully treated by dopamine agonist (DA) such as cabergoline, their management becomes problematic since a resistance to DA can occur and/or if the tumor displays features of aggressiveness, two conditions that are closely related.

AREAS COVERED

Epidemiology and medical treatment of prolactinomas; resistance to DA and molecular basis of DA-resistance; therapeutical alternatives in case of DA-resistant Prolactinomas and therapies in development; summarizing conclusions.

EXPERT OPINION

The management of DA-resistant prolactinomas requires a multidisciplinary approach by an expert team. Along with discussions about surgery with or without gamma knife radiosurgery, genetic screening for multiple endocrine neoplasia type 1 (MEN1) syndrome is actively discussed in a case-by-case approach. In case of surgery, a careful analysis of the tumor sample can provide information about its aggressivity potential according to recent criteria. Ultimately, temozolomide can be indicated if the tumor is rapidly growing and/or threatening for the patient.

Cytoskeleton actin-binding proteins in clinical behavior of pituitary tumors

Although generally benign, pituitary tumors are frequently locally invasive, with reduced success of neurosurgery and unresponsive to pharmacological treatment with somatostatin or dopamine analogues. The molecular basis of the different biological behavior of pituitary tumors are still poorly identified, but a body of work now suggests that the activity of specific cytoskeleton proteins is a key factor regulating both the invasiveness and drug resistance of these tumors. This review recapitulates the experimental evidence supporting a role for the actin-binding protein filamin A (FLNA) in the regulation of somatostatin and dopamine receptors expression and signaling in pituitary tumors, thus in determining the responsiveness to currently used drugs, somatostatin analogues and dopamine receptor type 2 agonists. Regarding the regulation of invasive behavior of pituitary tumoral cells, we bring evidence to the role of the actin-severing protein cofilin, whose activation status may be modulated by dopaminergic and somatostatinergic drugs, through FLNA involvement. Molecular mechanisms involved in the regulation of FLNA expression and function in pituitary tumors will also be discussed.

Stem Cells in Pituitary Tumors: Experimental Evidence Supporting Their Existence and Their Role in Tumor Clinical Behavior

Although generally benign, pituitary tumors frequently show local invasiveness and resistance to pharmacological therapy. After the demonstration of the existence of pituitary gland stem cells, over the past decade, the presence of a stem cell subpopulation in pituitary tumors has been investigated, analogous to the cancer stem cell model developed for malignant tumors. This review recapitulates the experimental evidence supporting the existence of a population of stem-like cells in pituitary tumors, focusing on their potential role in tumor initiation, progression, recurrence and resistance to pharmacological therapy.

Medically induced CSF rhinorrhea following treatment of macroprolactinoma: case series and literature review

PURPOSE

Although several reports have addressed cerebrospinal fluid (CSF) rhinorrhea following dopamine agonist (DA) therapy of macroprolactinomas, further study is warranted for this relatively uncommon entity. Toward this aim, our retrospective series and review of literature further clarifies recommendations in treatment of this rare problem.

METHODS

We retrospectively reviewed all macroprolactinoma cases in our hospital for a 15-year period. Our systematic search of PubMed identified original articles and reviews of all macroprolactinoma cases with an associated medication-induced CSF leak.

RESULTS

Five patients with drug-induced CSF leak were identified; four of these patients received cabergoline therapy an average of 6 weeks before the onset of rhinorrhea and then underwent surgical repair of the CSF leak. Of 35 published studies included, we identified 60 patients with medication-induced CSF leak. Medical therapy included bromocriptine in 34 patients, cabergoline in 21 patients, and use of both DAs in two patients. Three cases did include complete diagnostic and treatment data. Median time from initiation of the DA treatment to occurrence of rhinorrhea was 6 weeks. For CSF rhinorrhea, 49 patients underwent surgical repair (38 by the transnasal approach) and seven patients were treated nonoperatively.

CONCLUSION

Baseline skull base erosion in macroprolactinomas in combination with subsequent tumor shrinkage induced by DA therapy may result in spontaneous CSF rhinorrhea. Therefore, such patients should be advised about and monitored for this potential setback. Once CSF leak is diagnosed, prompt treatment must be carried out to avoid infectious complications. Transnasal surgery appears the most effective therapeutic approach.

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.

Nonalcoholic fatty liver disease with prolactin-secreting pituitary adenoma in an adolescent: A case report

RATIONALE

Nonalcoholic fatty liver disease (NAFLD), among the commonest chronic liver disorders in children and adolescents, is considered a reflection of the current obesity epidemic in children and adults. This liver disease has been linked with various metabolic disorders, but not with prolactinoma (PRLoma).

PATIENT CONCERNS

A 13-year-old Japanese girl manifested obesity, serum transaminase and γ-glutamyltransferase elevations, and amenorrhea. Abdominal ultrasonography showed fatty liver. Her serum prolactin concentration was elevated, and cranial magnetic resonance imaging showed a pituitary mass consistent with macroadenoma.

DIAGNOSES

NAFLD and PRLoma.

INTERVENTIONS AND OUTCOMES

After the patient's NAFLD failed to respond to diet and exercise, cabergoline treatment of the PRLoma decreased body weight, serum transaminase and γ-glutamyltransferase elevations, and ultrasonographic fatty liver grade as the tumor became smaller.

LESSONS

Physicians should consider the possibility of PRLoma when diet and exercise fail to improve fatty liver disease in a patient with endocrine symptoms such as amenorrhea.

Prolactinoma through the female life cycle

Prolactinomas are the most common secretory pituitary adenoma. They typically occur in women in the 3rd-6th decade of life and rarely in the pediatric population or after menopause. Most women present with irregular menses and/or infertility. Dopamine (DA) agonists, used in their treatment, are safe during pregnancy, but in most cases are discontinued at conception with close monitoring for signs or symptoms of tumor growth. Breastfeeding is safe postpartum, provided there was no significant growth during pregnancy. Some women will experience normalization of prolactin levels postpartum. Menopause may also decrease prolactin levels and even those with macroprolactinomas may consider discontinuing their DA agonist with close follow-up. Prolactinomas may be associated with decreased quality of life scores in women, and play a role in bone health and cardiovascular risk factors. This review discusses the current literature and clinical understanding of prolactinomas throughout the entirety of the female life cycle.