A giant prolactinoma presenting with unilateral exophthalmos: effect of cabergoline and review of the literature

Clinical and radiological presentation of parasellar ectopic pituitary adenomas: case series and systematic review of the literature

PURPOSE

Parasellar ectopic pituitary adenomas (pEPAs) are extremely rare tumors located out of the sella turcica. PEPAs are heterogeneous entities in terms of anatomical localization and secretion of anterior pituitary hormones.

METHODS

Multicenter retrospective study. Clinical charts' consultation of patients diagnosed with parasellar lesions, to identify all subjects fulfilling the diagnostic criteria of parasellar EPAs. Systematic review of the literature focused on the medical management of prolactin-secreting pEPAs and on the prevalence of radiological bone invasion in pEPAs.

RESULTS

We identified four cases of pEPAs: (1) 54-year-old female with a prolactin-secreting suprasellar EPA successfully treated with cabergoline; (2) 74-year-old male with a non-functioning EPA of the sphenoidal sinus treated with endoscopic transsphenoidal surgery; (3) 75-year-old female with a giant lesion of the skull base (maximum diameter 7.2 cm) diagnosed as a non-functioning EPA after biopsy; (4) 49-year-old male with a silent corticotroph EPA of the sphenoidal sinus and clivus. Three out of four cases had radiological evidence of invasion of the surrounding bone structures. A systematic review of the literature highlighted that medical therapy can be effective in prolactin-secreting pEPAs. Overall, we found mention of local invasiveness in 65/147 cases (44.2%), confirmed by radiological signs of bone invasion/erosion.

CONCLUSION

Our experience confirms the heterogeneity of pEPAs in terms of clinical and radiological presentation, as well as hormone secretion. PEPAs show a high frequency of radiological bone invasion, though similar to that of sellar pituitary adenomas. Although extremely rare, pEPAs need to be considered in the differential diagnosis of parasellar lesions.

Giant pituitary adenoma: histological types, clinical features and therapeutic approaches

Giant pituitary adenomas comprise about 6-10% of all pituitary tumors. They are mostly clinically non-functioning adenomas and occur predominantly in males. The presenting symptoms are usually secondary to compression of neighboring structures, but also due to partial or total hypopituitarism. Functioning adenomas give rise to specific symptoms of hormonal hypersecretion. The use of dopamine agonists is considered a first-line treatment in patients with giant macroprolactinomas. Somatostatin analogs can also be used as primary treatment in cases of growth hormone and thyrotropin producing giant adenomas, although remission of the disease is not achieved in the vast majority of these patients. Neurosurgical treatment, either through transsphenoidal or transcranial surgery, continues to be the treatment of choice in the majority of patients with giant pituitary adenomas. The intrinsic complexity of these tumors requires the use of different therapies in a combined or sequential way. A multimodal approach and a therapeutic strategy involving a multidisciplinary team of expert professionals form the basis of the therapeutic success in these patients.

Long-Term Clinical Outcomes of Invasive Giant Prolactinomas after a Mean Ten-Year Followup

Objective. The aim of this study is to observe clinical outcomes after more than ten years of followup in a group of patients with invasive giant prolactinomas (IGPs) treated with dopamine agonists (DAs). Methods. Twenty-five patients met the criteria of IGPs, among which 16 patients primarily received bromocriptine (BRC) and the other nine had undergone unsuccessful microsurgery prior to BRC treatment. Results. After a mean follow-up period of 135.5 ± 4.7 months, the clinical symptoms in all patients improved by different degrees. Tumor volume was decreased by a mean of 98.6%, and the tumors of 19 patients had almost completely disappeared. The mean duration of treatment at maximal doses of BRC was 48.5 months. At the last follow-up visit, nineteen patients had normal PRL levels, and 14 of these patients had received the low-dose BRC treatment (at an average of 2.9 ± 0.3 mg/d). Younger patients < 25 years had a significantly higher rate of persistent hyperprolactinemia after long-term BRC treatment (p = 0.043). Conclusion. DAs are a first-line therapy for IGPs because they can effectively achieve long-term control in both shrinking tumor volume and normalizing the PRL level, and majority of patients need low-dose DA maintenance. Younger patients are prone to persistent hyperprolactinemia despite long-term DA treatment.

Neurological, psychiatric, ophthalmological, and endocrine complications in giant male prolactinomas: An observational study in Algerian population

INTRODUCTION

Prolactinomas are less frequent, but more invasive in males. Giant ones (≥4 cm) are extremely rare in literature. Their neurological, psychiatric and endocrine complications are life threatening. Our aim was to report the largest mono center series in order to analyze their frequency, their characteristics, and their complications.

SUBJECTS AND METHODS

All patients had clinical examination, hormonal, ophthalmological, and radiological assessment based on computed tomography scan and cerebral magnetic resonance imaging. Positive diagnosis was based on clinical symptoms, high prolactin ± immunohistochemy study. Mixed adenomas were excluded by hormonal exploration and immunohistochemy. For those who received medical treatment only, a reduction in tumor size was considered a supplementary positive point for the diagnosis.

RESULTS

Among 154 male prolactinomas seen between 1987 and 2013, we observed 44 giant tumors (28.5%). Median age = 36 years, and 38.3% were under 30. Median tumor height = 53.95 mm (40-130) and median prolactin = 15,715 ng/ml (n < 20). Solid and cystic aspect ± calcifications was observed in 25%. 42 had cavernous sinuses invasion. Other invasions were: Posterior= 65.9%, anterior= 63.6%, temporal= 15.9% and frontal = 9%. For endocrine complications: Hypogonadism = 98.4%, thyrotroph and corticotroph deficits were seen in respectively 34%, and 32%. Posterior pituitary insufficiency was observed in one case. For ophthalmological complications: Optic atrophy = 46%, Ptosis = 6.8%, diplopia/strabismus = 4.5%. Neurological complications were: Memory loss and/or unconsciousness = 18.2%, epilepsy = 15.9%, frontal syndrome = 9% and obstructive hydrocephalus = 6.8%.

CONCLUSION

Giant prolactinomas account for 28% in our population. Severe neurological complications are frequent. But, obstructive hydrocephalus is rare, which argues for a slow progression.

Therapy of endocrine disease: the challenges in managing giant prolactinomas

Giant prolactinomas are rare tumours, representing only 2-3% of all prolactin (PRL)-secreting tumours and raising special diagnostic and therapeutic challenges. Based on several considerations developed in this review, their definition should be restricted to pituitary adenomas with a diameter of 40  mm or more, significant extrasellar extension, very high PRL concentrations (usually above 1000  μg/l) and no concomitant GH or ACTH secretion. Giant prolactinomas are much more frequent in young to middle-aged men than in women, with a male to female ratio of about 9:1. Endocrine symptoms are often present but overlooked for a long period of time, and diagnosis is eventually made when neurologic complications arise from massive extension into the surrounding structures, leading to cranial nerve palsies, hydrocephalus, temporal epilepsy or exophthalmos. PRL concentrations are usually in the range of 1000-100,000  μg/l, but may be underestimated by the so-called 'high-dose hook effect'. As in every prolactinoma, dopamine agonists are the first-line treatment allowing rapid alleviation of neurologic symptoms in the majority of the cases, a significant reduction in tumour size in three-fourths of the patients and PRL normalization in 60-70%. These extensive tumours are usually not completely resectable and neurosurgery has significant morbidity and mortality. It should therefore be restricted to acute complications such as apoplexy or leakage of cerebrospinal fluid (often induced by medical treatment) or to patients with insufficient tumoural response or progression. Irradiation and temozolomide are useful adjuvant therapies in a subset of patients with aggressive/invasive tumours, which are not controlled despite combined medical and surgical treatments. Because of these various challenges, we advocate a multidisciplinary management of these giant tumours in expert centres.

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.

Obstructive hydrocephalus, fifth nerve and hypothalamus involvement: acute presentation of a giant prolactinoma

INTRODUCTION

Pituitary tumors from lactotrope cells account for about 40% of all functioning pituitary cancers. Men tend to present with a larger, more invasive and rapid growth prolactinomas than women, possibly because hypogonadism features are less evident.

CASE REPORT

A 27-year-old, previously asymptomatic Saudi man presented with a 3-day history of emesis with severe left-sided frontal headache, left face and right upper limb numbness, with signs of obstructive hydrocephalus. Brain Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) revealed a giant pituitary mass occupying several regions (sellar, infra-sellar, and supra-sellar) measuring 6.5 × 5.7 × 5.9 cm, and invading the sphenoid sinus as well as the cavernous sinuses bilaterally, with intra-pituitary hemorrhage compressing the third ventricle causing obstructive hydrocephalus. Prolactin levels were >200,000 mIU/L, consistent with invasive giant prolactinoma (IGP). He was treated with Cabergoline which eventually normalized the prolactin level and significantly reduced the size of IGP.

CONCLUSION

This is a rare case of obstructive hydrocephalus with super-imposed intra-pituitary hemorrhage secondary to IGP, highlighting the importance of a full hormonal assessment for proper diagnosis and management.

[Macroprolactinoma revealed by an exophthalmos]

With the purpose of illustrating a particular circumstance of giant macroprolactinoma diagnosis, we report the case of a 54-year-old woman who was seen in the Endocrinology department with the suspected diagnosis of hyperthyroidism in presence of unilateral exophthalmos. The patient reported headaches during the last year and secondary amenorrhea since she was 38 years old. The ophthalmologic examination confirmed the unilateral left exophthalmos, which was associated with oculomotor paralysis and vision loss. The computed tomography demonstrated a great mass of the sella extending in all directions and destroying the bone. The hormonal investigation confirmed the diagnosis of prolactinoma, with a level of 8723 ng/ml, and revealed hypopituitarism. The start of bromocriptin treatment was followed by a fall in the prolactin level to less then 200 ng/ml in 1 month. This case is particular regarding the giant macroprolactinoma in a woman discovered by an unusual visual complication.

Long-term efficacy of bromocriptine in macroprolactinomas and giant prolactinomas in men

We prospectively analyzed presentations and long-term therapeutic responses to bromocriptine (BRC) in 29 newly diagnosed men with macroprolactinomas including 14 patients with 'giant prolactinoma'. Clinical symptoms, prolactin (PRL) levels and tumor size on MRI were measured before BRC and sequentially thereafter. The duration of follow-up were 6 to 96 (30.7 +/- 14.4) months. Pretreatment PRL ranged between 124 and 29200 ng/mL (1698 +/- 857.1) and tumor volume was between 2.81 and 132 cm(3) (21.1 +/- 24.3). Baseline PRL levels did not correlated with tumor volume (r = 0.45, P > 0.05). Significant decrease (P = 0.0003) in PRL, at least 96% of the pretreatment value from 1698 +/- 857.1 ng/mL to 42.4 +/- 30.6 ng/mL occurred in 26 patients. Persistent normalization of PRL levels (< 16 ng/mL) for at least 6 months was achieved in 12 patients (40.8%). Twenty-two patients (74.8%) achieved significant tumor shrinkage (P = 0.005) at study completion. An improvement in visual field defects (VFD) and restoration of libido and potency was observed in 40% and 33.3%, respectively. Trans-sphenoidal / trans-frontal pituitary surgery was performed in 9 patients (31%) for various reasons: pituitary apoplexy in 1, CSF rhinorrhea in 2, increasing prolactin in spite of BRC therapy in 3, and intolerant /resistant to BRC in 3 patients. These data suggest that, in male macro- and giant prolactinomas, dopamine agonists represent the first-line therapy effective in reducing PRL, restoration of libido and potency, improvement of VFD and determining tumor shrinkage.

Giant prolactinomas in men: efficacy of cabergoline treatment

OBJECTIVE

The term 'giant prolactinoma' can be used for tumours larger than 4 cm in diameter and/or with massive extrasellar extension. Cabergoline (CAB), a long-lasting dopamine agonist (DA), safe and well tolerated, is effective in normalizing PRL levels and inducing tumour shrinkage in micro- and macroprolactinomas. The purpose of this prospective study was to evaluate the efficacy and safety of CAB also for giant prolactinomas.

PATIENTS AND METHODS

Ten men with giant prolactinomas with a median age of 44.8 years were treated with CAB. Before CAB, four patients had previously undergone transsphenoidal surgery without modifying the parasellar extension of the tumour or their visual defects. Pretreatment serum prolactin (PRL) levels ranged between 1230 and 22 916 micro g/l (mean +/- SEM: 5794 +/- 1996) and tumour volume was between 21.8 and 105.5 cm3 (mean +/- SEM: 50.7 +/- 8.8). CAB was administered at an initial low dose of 0.5 mg three times a week and, in five patients who did not achieve serum PRL normalization, the dose was progressively increased up to 10.5 mg/week. The duration of treatment was 13-68 months (mean 38.9). PRL levels and pituitary target organ hormones were assayed before, after 30 days and then every 3 months after the beginning of CAB treatment. Magnetic resonance imaging (MRI) was carried out before, after 1-3 months, after 6 months and then every 10-12 months to evaluate tumour shrinkage.

RESULTS

In every patient, a significant PRL decrease (P = 0.0086) of at least 96% of the pretreatment values occurred (from 5794 +/- 1996 to 77 +/- 38, mean +/- SEM); a persistent normalization of PRL levels was achieved in five out of 10 patients (50%) beginning from the first 3-6 months of CAB treatment (only one patient needed 12 months of therapy). A significant tumour shrinkage (P = 0.0003) was achieved after 12 months of therapy in nine out of 10 patients (90%), with a volume reduction greater than 95% in three, of 50% in four and 25% in two patients. Tumour volume decreased from 50.7 +/- 8.8 to 28.6 +/- 9.4 and then to 22.3 +/- 8.8 cm3 (mean +/- SEM) after 6 and 12 months of CAB treatment, respectively. An improvement of visual field defects (VFD) was obtained in six of the seven patients presenting visual impairment before CAB treatment. Among the eight patients presenting libido and potency (L-P) failure, five normalized their PRL levels. In two of these a complete restoration of libido and potency was observed. Three patients with secondary hypoadrenalism and a patient with secondary hypothyroidism were treated with substitutive therapy during all the study time. The drug was well tolerated by all patients and no one discontinued the therapy.

CONCLUSIONS

These data suggest that, in giant, aggressive prolactinomas, CAB represents a first-line therapy effective in reducing PRL levels and determining tumour shrinkage.

Hyperprolactinemia: pathophysiology and management

Hyperprolactinemia is commonly found in both female and male patients with abnormal sexual and/or reproductive function or with galactorrhea. If serum prolactin levels are above 200 microg/L, a prolactin-secreting pituitary adenoma (prolactinoma) is the underlying cause, but if levels are lower, differential diagnoses include the intake of various drugs, compression of the pituitary stalk by other pathology, hypothyroidism, renal failure, cirrhosis, chest wall lesions, or idiopathic hyperprolactinemia. When a pituitary tumor is present, patients often have pressure symptoms in addition to endocrine dysfunction, such as headaches, visual field defects, or cranial nerve deficits. The large majority of patients with prolactinomas, both micro- and macroprolactinomas, can be successfully treated with dopaminergic drugs as first-line treatment, with normalization of prolactin secretion and gonadal function, and with significant tumor shrinkage in a high percentage of cases. Surgical resection of the prolactinoma is the option for patients who may refuse or do not respond to long-term pharmacological therapy. Radiotherapy and/or estrogens are also reasonable choices if surgery fails. In patients with asymptomatic microprolactinoma no treatment needs to be given and a regular follow-up with serial prolactin measurements and pituitary imaging should be organized. Currently, the most commonly used dopamine agonists are bromocriptine, pergolide, quinagolide and cabergoline. When comparing the plasma half-life, efficacy and tolerability of these drugs, cabergoline seems to have the most favorable profile, followed by quinagolide. Ifprolactin levels are well controlled with dopamine agonist therapy, gradual tapering of the dose to the lowest effective amount is recommended, and in a number of cases medication can be stopped after several years. Evidence to date suggests that cabergoline and quinagolide appear to have a good safety profile for women who wish to conceive, but hard evidence proving that dopamine agonists do not provoke congenital malformations when taken during early pregnancy is currently only available for bromocriptine. Once pregnant, dopamine agonist therapy should be immediately stopped, unless growth of a macroprolactinoma is likely or pressure symptoms occur. At our institution patients with symptomatic prolactinomas, both micro- and macroadenomas, are treated with cabergoline as the first-line aproach. In the small group of patients who do not respond to this treatment, or who refuse long-term therapy, surgery is offered. Radiotherapy is given if both pharmacologic therapy and surgery fail.