Unusual clinical presentations of giant prolactinomas

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.

Treatment Strategy for Giant Invasive Macroprolactinoma with Spontaneous Cerebrospinal Fluid Rhinorrhea: A Case Report and Literature Review

BACKGROUND

Spontaneous cerebrospinal fluid (CSF) rhinorrhea associated with untreated prolactinomas is rare, which is in contrast to medical treatment-induced CSF rhinorrhea. Previous studies have suggested that cessation of drug administration should be the first line of treatment for prolactinoma with medically induced CSF rhinorrhea. On the other hand, there is no standard treatment strategy for prolactinoma with the development of spontaneous CSF rhinorrhea, because of its complicated pathology. Here, we report a case of giant invasive macroprolactinoma with spontaneous CSF rhinorrhea, and discuss the treatment strategy for this complicated condition with a review of the relevant literature.

CASE DESCRIPTION

A previously healthy 39-year-old man presented with 1-year history of intermittent clear fluid nasal discharge with headache and vomiting. Magnetic resonance imaging showed a large parasellar mass with destruction of the skull base. This tumor was diagnosed as prolactinoma with hypopituitarism based on the results of hormone examinations. Tumor resection with skull base reconstruction in the endoscopic endonasal approach was performed because CSF rhinorrhea was aggravated by bromocriptine loading test and administration of dopamine agonist. Life-threatening bacterial meningitis occurred after surgery, which was cured with antibiotics along with resolution the CSF rhinorrhea.

CONCLUSIONS

Careful consideration is necessary before applying standard first-line protocols with dopamine agonist administration in patients with prolactinoma, especially in cases with spontaneous CSF rhinorrhea. An appropriate treatment strategy should be planned according to the individual case, including factors such age, sex, pituitary function, tumor mass size, prolactin concentration, and condition of CSF leakage.

Giant Prolactinomas

Prolactin-secreting adenomas (prolactinomas) are the most common secreting adenomas of the pituitary. Microprolactinomas (diameter <10 mm) are frequently diagnosed in women, whereas macroprolactinomas (maximum diameter ≥10 mm) are generally seen in men. Most macroprolactinomas measure between 10 and 40 mm. Giant prolactinomas, measuring >40 mm, are rare, accounting for only 1-5% of all prolactinomas. Although generally benign, giant prolactinomas are aggressive and invasive, extending into the suprasellar region and also involving the cavernous sinuses. The optic chiasm is frequently involved, which leads to visual damage, and patients occasionally suffer from ophthalmoplegia. Long-term (usually lifetime) therapy with high-dose dopamine agonists (cabergoline or bromocriptine), together with pituitary surgery in some cases and radiotherapy if required, can achieve biochemical remission, tumor control, and clinical improvement in most patients.

Cabergoline-Induced Pneumocephalus Following Treatment for Giant Invasive Macroprolactinoma Presenting With Spontaneous Cerebrospinal Fluid Rhinorrhea

Cerebrospinal fluid (CSF) rhinorrhea is rarely reported as the first presenting feature of giant invasive macroprolactinomas. Cerebrospinal fluid rhinorrhea is usually reported as a complication of trauma, neurosurgical, and skull-based procedures (such as pituitary surgery or radiations), and less frequently after medical treatment with dopamine agonists (DAs) for macroprolactinomas. This phenomenon results from fistula creation that communicates between the subarachnoid space and the nasal cavity. Meanwhile, pneumocephalus is another well-recognized complication after transsphenoidal surgery for pituitary macroadenomas. This entity may present with nausea, vomiting, headache, dizziness, and more seriously with seizures and/or a decreased level of consciousness if tension pneumocephalus develops. Case reports about the occurrence of spontaneous pneumocephalus after medical treatment with DAs without prior surgical interventions are scarce in the literature. Our index case is a young man who was recently diagnosed with a giant invasive prolactin-secreting pituitary macroadenoma with skull base destruction. A few months before this diagnosis, he presented with spontaneous CSF rhinorrhea with no history of previous medical or surgical treatment. In this case report, we report an uncommon presentation for giant invasive macroprolactinoma with a CSF leak treated with cabergoline that was subsequently complicated by meningitis and pneumocephalus. This is a very rare complication of cabergoline therapy, which occurred approximately 1 month after treatment initiation.

Giant prolactinomas larger than 60 mm in size: a cohort of massive and aggressive prolactin-secreting pituitary adenomas

OBJECTIVES

Prolactin (PRL)-secreting macroadenomas usually measure between 10 and 40 mm. Giant (adenoma size ≥40 mm) PRL-tumors are not common, and larger prolactinomas (maximal diameter ≥60 mm) are rare, and their management outcomes have not been well characterized.

METHODS

We have identified 18 subjects (16 men, 2 females) with giant PRL-adenomas (size ≥60 mm; PRL > 1000 ng/ml) and summarized their characteristics and response to treatment.

RESULTS

Mean age was 36.3 ± 13.5 years (range 12-59 years). Mean adenoma size was 71.8 ± 10.2 mm (60-92 mm). Complaints at presentation included headaches in 11 patients, visual deterioration in 9, sexual dysfunction in 9 males, and behavioral changes in two. Fourteen (78 %) had visual field defects. Mean PRL at presentation was 28,465 ng/ml (range 1300-270,000). All patients were treated with cabergoline (3.9 ± 2.0 mg/week), except for one who received bromocriptine. Treatment achieved PRL normalization in 11/18 patients within a median interval of 20 months. Visual improvement occurred in 12/14 patients with pre-treatment visual abnormalities. Nine patients underwent surgery (transsphenoidal, 7; transcranial, 2). None of the seven patients with elevated PRL before surgery achieved remission post-operatively. After a follow-up of 7.8 ± 5.1 years, 15/18 patients had significant adenoma shrinkage. Eleven patients are normoprolactinemic, 3 are partially controlled (PRL < 3 × ULN), and 4 remain with significantly elevated PRL. Most patients reported disappearance or improvement of their complaints.

CONCLUSIONS

These enormous PRL-adenomas are invasive but respond fairly well to medical treatment. Long-term therapy with high dose cabergoline together with a pituitary surgery in some patients was the key for their successful management, achieving biochemical and clinical remission in most patients.

Management of macroprolactinomas

Prolactin (PRL) secreting tumors are the most common functional neoplasms of the pituitary and are commonly subdivided into microprolactinomas (<10 mm) and macroprolactinomas (≥10 mm) according to their baseline diameter. Patients with prolactinoma present with symptoms evolving from hyperprolactinemia and with those caused by pressure of the expanding mass on surrounding tissues, including the optic chiasm and the cavernous sinuses. We hereby describe the possible complications of macroprolactinomas, including mass effects, hypopituitarism, CSF leak and apoplexy and discuss their relevant management.

In general, all patients harboring macroprolactinomas should be treated, the objectives being to achieve normal or near normal PRL levels, to reduce or stabilize adenoma size and to recover altered pituitary axes. Medical therapy with dopamine agonists (DA) is the preferred initial treatment for the vast majority of patients harboring prolactinomas. Pituitary surgery is indicated in patients who cannot tolerate or are resistant to therapy with DAs, patients that seek fertility and harbor adenomas that impinge on the optic chiasm, psychiatric patients with contraindication to DA treatment and patients presenting with pituitary apoplexy or a cerebrospinal fluid (CSF) leak. In addition, in this review, several patient populations with unique clinical characteristics will be discussed separately namely postmenopausal women, the elderly, children and patients with pituitary carcinoma.

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.

Macroprolactinoma: a diagnostic and therapeutic update

Prolactinomas are the most common type of pituitary adenomas. Macroprolactinomas are the name used for these tumors when their size is ≥ 1 cm. These tumors commonly cause symptoms due to the excessive production of prolactin as well as complaints caused by tumor mass and compression of neural adjacent structures. Clinical diagnosis and assessment of macroprolactinoma are based on the measurement of serum prolactin concentrations and the morphological evaluation of the pituitary gland by magnetic resonance imaging. Dopamine agonists are the first-line treatment modality, with cabergoline being preferred to bromocriptine, because of its better tolerance and feasibility of administration. Cabergoline therapy has been reported to achieve normalization of prolactin levels and gonadal function and reduction of tumor volume in >50% of patients with macroprolactinoma. Resistance or intolerance to dopamine agonists are the main indications for transsphenoidal adenomectomy in patients with macroprolactinoma. External radiation therapy has been used in patients with poor response to medical and surgical procedures. Clinically significant tumor growth may occur during pregnancy in women with macroprolactinomas, especially if they have not received prior surgical or radiation therapy. Visual fields should be assessed periodically during pregnancy and therapy with dopamine agonists is indicated if symptomatic tumor growth occurs. Cystic and giant prolactinomas as well as the rare cases of malignant prolactinomas have special peculiarities and entail a therapeutic challenge.