Giant basal prolactinoma extending into the nasal cavity

Pituitary Adenomas Presenting as Sinonasal or Nasopharyngeal Masses: A Case Series Illustrating Potential Diagnostic Pitfalls

We present a series of nonectopic pituitary adenomas presenting as polypoid sinonasal or nasopharyngeal masses. Thirteen cases diagnosed by biopsies from the nasal cavity, sinuses, or nasopharynx were identified from a series of 1288 surgical pituitary specimens. The patients included 5 men and 8 women ranging from 29 to 69 years of age. The presentations included nasal obstruction (4 cases), headaches (3), visual defects (2), recurrent nose bleeds (1), rhinorrhea (1), sepsis (1), fatigue (1), and hyperthyroidism (1). All patients had large tumors involving the sella and extending inferiorly to involve the sphenoid sinus in 10 cases, ethmoid in 8, nasopharynx in 3, nasal cavity in 6, maxillary and frontal sinuses in 1 case each. In 3 patients, the biopsy was from the nasopharynx, in 4 from the nasal cavity, in 4 from the sphenoid sinus, and in 2 from the ethmoid sinus. The correct diagnosis of pituitary adenoma was initially made in 10 cases. In 3 cases the initial diagnosis was incorrect; 2 tumors were classified as olfactory neuroblastoma, one of those was reclassified as neuroendocrine carcinoma, and 1 case was initially diagnosed as neuroendocrine carcinoma with aberrant adrenocorticotrophic hormone expression. Clinical follow-up (2 to 25 y) and treatment information was available in 10 cases. All 10 patients were alive, either free of disease (4 cases) or with disease (6 cases). In 2 cases, the wrong diagnoses led to incorrect treatment with significant morbidity. These cases illustrate that pituitary adenomas can invade nasopharynx and sinonasal cavities and when they do, they present a possible diagnostic pitfall with potentially serious consequences. We demonstrate the need to always consider this entity when encountering a nasopharyngeal or sinonasal tumor with neuroendocrine features.

Clinical presentation and response to therapy in patients with massive prolactin hypersecretion

Prolactin hypersecretion from a pituitary adenoma usually results in a serum prolactin level less than 1,000 ng/ml. During therapy with a dopamine agonist, prolactin levels usually normalize and the tumors shrink substantially. In the past few years, we have seen three men who presented with serum prolactin levels greater than 10,000 ng/ml. All presented with large tumors, visual field deficits, and hypogonadotropic hypogonadism. All other pituitary hormones were normal. In all three patients, significant tumor shrinkage was achieved with improvement or resolution of headaches and visual field deficits. None of our patients has been able to achieve a normal prolactin or testosterone. A literature review identified 32 patients with prolactin levels of more than 10,000 ng/ml. Twenty-six (81%) were males. Most had large tumors, headaches and visual field defects. Even with the addition of surgery and/or radiation therapy to medical therapy, normalization of serum prolactin occurred in only six patients (19%) and only one man achieved a normal testosterone. We conclude that in patients with massive prolactin hypersecretion, therapy with a dopamine agonist will lead to tumor shrinkage and improvement of mass effects, but usually does not normalize prolactin or testosterone. Rather than waiting for maximal prolactin reduction, we would recommend early institution of testosterone replacement therapy.

Treatments of multi-invasive giant prolactinoma

We present a 68-year-old male patient with an exceptionally aggressive tumour which invaded to the skull base, cavernous sinus, nasopharynx, sphenoid sinus, pituitary fossa, bilateral parasellar regions, premedullary cistern, and left infratemporal fossa. Headache was the only symptom. The serum prolactin level was 95,973 ng/ml. The patient was treated by right subfrontal craniotomy with removal of the tumour. Because it did not respond well to surgical treatment and the electron micrograph showed abundant secretory granules in some parts of the specimen, post-operative radiotherapy and bromocriptine therapy were instituted. After combined therapies and a long-term follow-up, only little residual pituitary tumour was seen with serum prolactin progressively dropped to 717 ng/ml with no obvious symptoms. The histological findings, the ideal treatments and the clinical course of multi-invasive giant prolactinoma will be discussed.

Giant prolactinomas: clinical management and long-term follow up

OBJECT

Giant prolactinomas are rare tumors whose treatment and outcome has only been addressed in isolated case reports. The authors document the long-term follow-up findings and clinical outcome in a group of patients with giant prolactinomas.

METHODS

This study is a retrospective chart and clinical review of more than 2000 cases of pituitary tumors treated at the authors' institution, of which 10 met the criteria for inclusion (prolactin level > 1000 ng/ml, diameter > 4 cm on neuroimaging studies, and clinical signs of hyperprolactinemia/mass effect). The average follow-up duration was 6.7 years after initial treatment with either bromocriptine or transsphenoidal resection. In more than 90% of the patients in this series the disease was controlled by medical treatment with bromocriptine alone; the other 10% required early surgery via transsphenoidal resection. All patients had improvement in visual symptoms. All tumors had extrasellar components, five of which exhibited frank invasion of the cavernous sinus. Tumor volume on magnetic resonance imaging was decreased on average by 69%; this occurred at a faster rate and in larger amounts when treated with bromocriptine than has been reported in the literature for macroprolactinomas.

CONCLUSIONS

According to long-term follow-up findings, giant prolactinomas are exquisitely responsive to dopamine agonist therapy. In giant prolactinomas the prolactin level does not correlate with size. The main indication for early surgery is intratumoral hematoma, whereas our main indications for late surgery are cerebrospinal fluid leakage caused by medical treatment, or an increasing prolactin level despite medical therapy. Checking prolactin levels in suspicious sellar and/or suprasellar lesions may be diagnostic and prevent unnecessary surgery.

Prolactinoma with preferential infrasellar extension: a report of two cases

The authors describe two male patients with prolactinomas which were incidentally found either during the course of a complete work up for headache or after minor head trauma. Since these tumours were located mainly in the sphenoid bone and did not show any upward growth to the suprasellar region, they were initially thought to be a primary skull base tumour; however, the serum prolactin levels of these patients were 1,179 ng/ml and 3,260 ng/ml, respectively. The authors thus emphasise the need to recognise this peculiar infrasellar growth pattern of prolactinoma.

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

We report the case of a 45-year-old male presenting with unilateral exophthalmos due to a large tumoral mass invading the skull base. Ophthalmologic examination did not show any visual field defects. Imaging techniques demonstrated extension of a huge tumor (approx. 8x8x8 cm) into the right orbit and nasopharynx. Endocrine work-up revealed grossly elevated serum prolactin (PRL) levels (26,466 microg/l, nl. < 12), pointing to a large, invasive macroprolactinoma. Stimulation tests indicated associated partial adrenal and growth hormone deficiencies. Planned surgery was abandoned, and the patient was instead treated with the long-acting dopamine agonist, cabergoline. Over a period of one year, serum PRL dropped to 131 microg/l, while the tumor mass shrank to less than 50% of its original volume (with 3.5 mg/week of cabergoline). The exophthalmos disappeared, and the patient did not develop rhinorrhea or any other side effects from treatment with cabergoline. The efficacy was maintained throughout the second year (ultimate serum PRL 74 microg/l, and final size less than 10% of the original). With reference to this case, we review other macroprolactinomas reported in the recent literature for associated exophthalmos, grossly elevated serum PRL levels (> or = 15,000 microg/l), and/or "giant" size (> or = 4 cm in maximum diameter). We highlight the use of dopamine agonists in the treatment of prolactinomas with such unusual characteristics.

Pituitary adenomas with infra-sellar extension into the nasopharynx

Three cases of pituitary adenomas with infra-sellar extension into the nasopharynx and the nasal cavities are reported. The clinical signs were epistaxis, nasal obstruction, painful sinuses and purulent rhinorrhoea. The initial diagnostic hypothesis was that of a carcinoma of the nasopharynx or the sinuses in all three cases. The diagnosis was made by histological examination and measurement of plasma hormone levels. These cases highlight the difficulty in the diagnosis of such tumours due to their misleading clinical, radiological and histological features.