Multiple intracranial metastases from a prolactin secreting pituitary tumour

Pituitary metastasis of malignant melanoma misdiagnosed as pituitary adenoma: A case report and systematic review of the literature

We report a case of malignant melanoma revealed by a metastasis to the pituitary gland. The tumor was misdiagnosed as a pituitary adenoma and aggressive transsphenoidal surgery was complicated by a cerebrospinal fluid fistula. Nine weeks later, the patient presented multiple leptomeningeal and brain metastases spreading from the sellar region. Regarding these observations, we conducted a systematic review of the literature in order to investigate clinicoradiological features that should lead clinicians to suspect pituitary metastasis and how it should impact the surgical management.

Multiple intracranial and spinal metastases from a nonfunctioning pituitary adenoma following multiple surgeries: an illustrative case with 16 years of follow-up

Pituitary adenomas are the third most common primary intracranial tumor; however, those with postoperative metastases are very rare and are classically considered as pituitary carcinomas. The field of neurosurgery has struggled with diagnosing and treating these unusual lesions. In this report, we retrospectively analyze the clinical features, imaging findings, pathological characteristics and prognosis of one patient with non-hormone-secreting pituitary adenoma who had multiple intracranial and spinal metastases and underwent four surgeries in a 16-year follow-up period. In addition, on the basis of the existing literature, we explore the underlying mechanisms of, as well as the preventive and therapeutic strategies used to treat, pituitary carcinomas and postoperative metastasis of pituitary tumors.

Long-term follow-up of growth hormone-producing pituitary carcinoma with multiple spinal metastases following multiple surgeries: case report

This report describes a rare case of a patient with growth hormone (GH)-secreting pituitary adenoma with malignant transformation resulting in multiple metastases to the dura mater of the cerebral convexity and high cervical spine. The patient was a 60-year-old man with a previous history of pituitary adenoma with suprasellar extension who had undergone transsphenoidal surgery, craniotomy for a convexity tumor, and suboccipital craniotomy for a cerebellar tumor. Thirteen years after the initial surgery, suboccipital craniotomy for a cervicomedullary junction tumor and cervicospinal surgery for a metastatic tumor was performed. Histologic findings of resected specimens demonstrated that the primary pituitary tumor was typical adenoma (similar to specimens from the initial surgery) but that the cerebellar and the dural tumor from the high cervical spine had a high incidence of mitotic figures, and cellular anaplasia with nuclear polymorphism and necrosis. In addition, the serum levels of GH were noted to have decreased with recurrence of the tumor. It was concluded that patients with pituitary adenoma, even when benign, must be carefully followed for signs of malignant transformation, and spinal or distant metastases.

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 carcinoma: a review of the literature

Pituitary carcinomas, defined as distant metastases of a pituitary neoplasm, are rare; fewer than 140 reports exist in the English literature. The initial presenting pituitary tumor is usually a secreting, invasive macroadenoma, with adrenocorticotropic hormone (ACTH)--and prolactin (PRL)--secreting tumors being the most common. The latency period between the diagnosis of a pituitary tumor and the diagnosis of a pituitary carcinoma is 9.5 years for ACTH-producing lesions and 4.7 years for PRL-secreting tumors. Survival after documentation of metastatic disease is poor; 66% of patients die within 1 year. Treatment options include additional surgery, radiotherapy, and chemotherapy, all of which are associated with poor results. Future studies will focus on identifying those invasive pituitary tumors most likely to metastasize and treating them aggressively before they progress to pituitary carcinomas.

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.

Late development of frontal prolactinoma after resection of pituitary tumor

The unusual case of a patient with a frontal lobe prolactinoma developed 14 years after resection of a histologically benign pituitary adenoma is presented. Sixteen years after resection of this frontal mass, and 30 years after the first intervention, the patient is symptom-free and without evidence of new intracranial tumors. The possibility that frontal tumor resulted as the late proliferation of microscopic tumor seeding that took place in the course of the first surgery, is suggested. Although this case can be considered as a pituitary carcinoma, the clinical course supports that tumor seeding from pituitary tumors not necessarily indicates a poor prognosis.

Progression on metastatic neuroendocrine carcinoma from a recurrent prolactinoma: a case report

A 54 year old man was referred to the department of neurosurgery for frontal headache and vomiting. The patient was known in the department because of previous multiple surgery for a locally invasive pituitary prolactinoma (eight years, three years, and one year previously). The neurological examination revealed a frontal mass, which adhered to the dura, suggesting a meningioma. One year later, a left temporal metastasis was removed. Three months later, the patient died, with spinal metastases, of massive lung embolism. Histology revealed a progression of adenohypophyseal prolactinoma on neuroendocrine carcinoma, with an increase in proliferating indexes and modification of hormone production. This study documents a 10 year history of a rare prolactin producing pituitary carcinoma, which metastasised via liquoral flow.

Multiple intracranial recurrent tumors with hyperprolactinemia combined with a parasellar malignant fibrous histiocytoma long after transfrontal surgery and irradiation to a pituitary adenoma

We herein describe a 40-year-old woman with hyperprolactinemia, an empty sella and two extrasellar intracranial recurrent tumors which were revealed 23 years after the first transfrontal craniotomy and 18 years after the second transfrontal surgery and irradiation to a provable prolactin-producing pituitary macroadenoma. One recurrent tumor was in the right orbital apex causing right oculomotor nerve palsy, and the other tumor was in the right apex partispetrosae and foramen jugulare. Although her serum prolactin level decreased after the administration of bromocriptine mesilate, and the size of the two tumors remained unchanged, a malignant fibrous histiocytoma, which might have been induced by the irradiation 18 years before, grew rapidly in the right suprasellar-prepontine cistern to the right pedunculus cerebralis, leading to a poor prognosis. This case confirmed the importance of the life-lasting follow-up of pituitary adenomas treated with surgery and/or irradiation therapy. Not only ectopic recurrence of the primary tumor but also post-irradiation tumors may become apparent long after the removal of the primary tumor.

Pituitary carcinoma: an ultrastructural study of eleven cases

Pituitary carcinomas are very rare. Defined as adenohypophysial tumors that undergo craniospinal and/or systemic metastasis, most are PRL- or ACTH-producing. Their ultrastructural features, particularly relative to benign adenomas of similar functional type, have not been sufficiently explored. Eleven cases of immunohistochemically characterized pituitary carcinoma with documented cerebrospinal and/or systemic metastases were collected from various institutions and studied by transmission electron microscopy. The tumors were surgically removed from 7 women and 4 men ranging in age between 28 and 74 years (mean, 50 years). All were endocrinologically functioning. Six tumors secreted PRL; three were ACTH-producing; one each was GH/PRL- and TSH-producing. The patients with the ACTH-producing tumors had all presented with Cushing's disease and two of them had undergone adrenalectomy (Nelson syndrome). In most cases significant cellular atypia and mitotic activity were observed. In terms of morphologic features of functional differentiation, electron microscopy revealed that in 9 cases the tumor cells maintained at least some ultrastructural markers of their basic phenotype. A unique feature in 2 ACTH carcinomas was the variable admixture of smooth endoplasmic reticulum with intermediate (cytokeratin) filaments. In 2 cases, both PRL-producing carcinomas, the cell type comprising the tumor could not be identified on an ultrastructural basis alone. Ultrastructural investigation of pituitary carcinomas confirms their endocrine nature and, in most but not all cases, reveals their functional differentiation. Despite the diagnostic utility of electron microscopy in the assessment of these rare tumors, the distinction of pituitary carcinoma from pituitary adenoma cannot be firmly made on ultrastructural grounds alone.

Telomerase activity and the expression of telomerase components in pituitary adenoma with malignant transformation

BACKGROUND

Telomerase activity responsible for cellular immortality may participate the development of human cancers. Telomerase is a multisubunit ribonucleoprotein composed of at least three components: hTERT, hTERC, and TEP1. This is the first report showing telomerase activity and telomerase component expression in pituitary adenoma with histological malignant transformation.

DESCRIPTION

A 16-year-old male with a prolactin-producing pituitary adenoma with metastasis is presented. The patient underwent three partial resections of an intra- and suprasellar lesion over a 2-year period and received focal irradiation. Eight years after the first admission, a metastatic lesion to the subarachnoid space around the medulla oblongata was detected and the lesion was resected as the fourth operation. Furthermore, the suprasellar lesion showed regrowth and partial resection was performed as the fifth operation. The last two specimens were diagnosed as pituitary carcinoma. Radiotherapy with gamma knife was performed for the residual suprasellar lesion and a new lesion in the left temporal lobe after the fifth operation. Telomerase activity was examined by TRAP/TRAP-HPA methods, qualitatively and quantitatively. Telomere length was examined by Southern blot analysis, and the expression of telomerase components (hTERT, hTERC, and TEP1) was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). The MIB1 index, telomerase activity, and hTERT expression increased according to histologic malignancy chronologically in this patient. None of the specimens showed immunoreactivity for p53, EGFR, or bc12. No telomerase activity was detected in pituitary adenomas without malignant transformation, other benign brain tumors, or normal brain tissues.

CONCLUSION

We report a patient with pituitary adenoma transforming to carcinoma. The tumor cells acquired immortality and revealed malignant transformation during the course of the disease, that was proved by an increase of telomerase activity and hTERT expression.

Pituitary carcinoma: a clinicopathologic study of 15 cases

BACKGROUND

Pituitary carcinomas are rare adenohypophysial neoplasms, the definition, diagnosis, therapy, and prognosis of which are controversial.

METHODS

Pituitary carcinomas were defined as primary adenohypophysial neoplasms with documented craniospinal and/or systemic metastases. The authors report a clinicopathologic study of 15 examples examined by light microscopy, immunohistochemistry, and image analysis. Both proliferative activity and p53 tumor suppressor gene expression were studied.

RESULTS

The study group consisted of 15 patients, including 8 males and 7 females ranging in age from 34-71 years (mean, 56 years). Of these patients, seven had adrenocorticotropic hormone (ACTH)-producing tumors (four in the context of Nelson's syndrome), seven had prolactin-producing tumors, and one had a nonfunctioning tumor. No evidence of diabetes insipidus was seen in any case. Fourteen tumors were initially considered macroadenomas. Of the ten cases for whom tumor extent was known, all had invasive tumors. The interval from the initial diagnosis of adenoma to that of carcinoma ranged from 0.3 to 18.0 years (mean, 6.6 years; median, 5.0 years); the longest mean interval (15.3 years) occurred for patients with Nelson's syndrome. The latency was twice as long for ACTH-producing tumors as for prolactin (PRL) cell tumors (9.5 vs. 4.7 years). All carcinomas showed a greater tendency toward systemic metastasis than craniospinal metastasis; the rate of systemic metastasis was 71% for PRL cell tumors and 57% for ACTH-producing tumors. Thirteen percent of tumors showed both patterns of metastasis. Fully 50% of primary tumors and the majority of metastases showed nuclear pleomorphism and/or hyperchromasia. The mean mitotic, MIB-1, and proliferating cell nuclear antigen indices for primary tumors and metastases were as follows: 2/10 high-power field (hpf), 2.6% and 11%, respectively; 6/10 hpf, 7.8% and 16%, respectively. Staining for p53 protein was noted in 57% of primary tumors and 88% of metastatic tumors; a relative increase in p53 expression in metastases was noted in 83%. All but one of the primary and metastatic tumors were aneuploid. The most common treatments were radiation therapy and, for PRL cell carcinomas, dopamine agonist administration. Both treatments provided only palliation. Eighty percent of the patients died of metastatic disease 7 days to 8 years after the diagnosis of carcinoma; of these, 66% died within 1 year. At last follow-up, 20% of patients were alive with metastases 9-18 months after diagnosis.

CONCLUSIONS

Nearly all pituitary carcinomas present as functioning, microscopically atypical or mitotically active, invasive macroadenomas. By definition, after an interval related to their immunotype, all metastasize. The tumors show a greater tendency toward systemic metastasis than craniospinal metastasis and are associated with poor prognosis. Radiation and dopamine agonist therapy generally provide only palliation. Proliferation indices and p53 expression tend to be higher in metastases than in primary tumors. The current definition of pituitary carcinoma requires the demonstration of metastasis; however, high mitotic and MIB-1 labeling indices as well as p53 immunoreactivity suggest the diagnosis and appear to be of prognostic significance. A redefinition of aggressive pituitary tumors is proposed--one that facilitates the recognition of tumors prone to metastasis.

Diagnosis and drug therapy of prolactinoma

A prolactin-secreting pituitary tumour is the most frequent cause of hyperprolactinaemia that commonly occurs in clinical practice. Prolactinomas occur more frequently in women than in men and may differ in size, invasive growth and secretory activity. At presentation, macroadenomas are more frequently diagnosed in men. Specific immunohistochemical stains are necessary to prove the presence of prolactin in the tumour cells. The main investigations in the diagnosis of a prolactin-secreting adenoma are hormonal and radiological. As prolactin is a pulsatile hormone, it is a general rule to obtain several blood samples by taking a single sample on 3 separate days or 3 sequential samples (every 30 minutes) in restful conditions. Prolactin levels of 100 to 200 micrograms/L are commonly considered diagnostic for the presence of a prolactinoma; however, prolactinoma cannot be excluded in the presence of lower levels, and prolactin levels > 100 micrograms/L are present in some patients with idiopathic hyperprolactinaemia. Several dynamic function tests have been proposed to differentiate idiopathic from tumorous hyperprolactinaemia. Although they could be used for group discrimination, these tests cannot be used for individual patients. To differentiate between a prolactinoma and a pseudoprolactinoma, thyrotrophin response to a dopamine receptor antagonist may be used, as only prolactinomas may have an increased response. A short course of dopaminergic drugs may also be of some help, as in macroprolactinomas only a shrinkage may be observed. After hyperprolactinaemia is confirmed, imaging with computerised tomography (CT) and magnetic resonance imaging (MRI) are necessary to define the presence of a lesion compatible with a pituitary tumour. There is now a general agreement that medical therapy is of first choice in patients with prolactinomas. Bromocriptine, the most common drug used in this condition, is a semisynthetic ergot alkaloid that directly stimulates specific pituitary cell membrane dopamine D2 receptors and inhibits prolactin synthesis and secretion. In most patients, a reduction or normalisation of prolactin levels is usually observed, together with the disappearance or improvement of clinical symptoms. The sensitivity to bromocriptine is variable and patients may need different dose of the drug. Bromocriptine is also able to shrink the tumour in most patients; however, a few reports of disease progression during therapy have been described. The need for close follow-up, including prolactin levels and CT or MRI studies, is therefore emphasised. Bromocriptine is conventionally given in 2 or 3 daily doses; however, a single evening dose has been shown to be equally effective. Bromocriptine is usually well tolerated by the majority of patients; some adverse effects (nausea, vomiting, postural hypotension) may be initially present, but they usually wear off in time. To prevent such adverse effects it is advisable to start treatment with a low dose during the evening meal and gradually increase the dose over days or weeks. A few patients are unable to tolerate oral bromocriptine, so different formulations of bromocriptine or alternative dopamine agonist drugs (lisuride, terguride, metergoline, dihydroergocryptine, quinagolide, cabergoline, pergolide) have been proposed. Of particular clinical relevance because of their good tolerability and sustained activity are cabergoline and quinagolide. Particular attention should be paid to pregnancy in prolactinoma patients, as tumour enlargement has been reported. As the risk for this occurrence is low in patients with microprolactinoma, there is a general agreement that the drug can be stopped once pregnancy is diagnosed. In patients with macroprolactinoma the risk of tumour enlargement is higher. Therefore, primary therapy with bromocriptine until the tumour has shrank is suggested before pregnancy is attempted. Bromocriptine should be stopped as soon as pregnancy is confirmed, but re

Pituitary Carcinomas

Pituitary carcinomas are defined by their metastatic growth. Most of them also invade into surrounding tissues. They should be classified by the site of their metastases (cerebrospinal, systemic, or combined) and by the presumable cell type of origin, respectively with the hormone being demonstrable by immunohistochemistry (adrenocorticotrophic hormone [ACTH], prolactin [PRL], growth hormone [GH], hormone-negative). Pituitary carcinomas develop from invasive adenomas. Nearly all tumors had been treated by surgery or X-ray before they metastasized. Since 1976, 37 cases demonstrated with modern methods were reported: 23 had metastasized into the brain or meninges, 10 showed extracerebral metastases, and 4 showed both types of metastases. In our collection of pituitary tumors, three carcinomas (0.13%) were identified: two with systemic metastases (one ACTH secreting and one PRL secreting) and one with meningeal dissemination and ACTH production. The diagnosis of pituitary carcinomas should be based on four criteria: a demonstrable metastasis, identification of the primary tumor as a pituitary tumor, similarity between the structure and immunohistological marker expression of metastasis and primary tumor, and exclusion of an alternative primary tumor.

Prolactin-secreting pituitary carcinoma with implants in the cheek pouch and metastases to the ovaries. A case report and literature review

BACKGROUND

Prolactin-secreting pituitary carcinomas are uncommon, locally destructive neoplasms that rarely metastasize outside the central nervous system. The authors report a case of a prolactin-secreting tumor that initially presented as the empty sella syndrome. Two recurrences along transsphenoidal surgery tracts in cheek pouches were followed by distant metastases later in the abdomen and pelvis. Only 10 previous cases of either extracranial or intracranial metastases from prolactin-secreting pituitary carcinomas have been reported. No metastases below the diaphragm have been reported previously.

METHODS

The patient's cheek pouch implants, lymph node metastases, ovarian metastases, and uterine metastases were studied with prolactin-specific immunohistochemistry.

RESULTS

Long term treatment with bromocriptine, several debulking surgeries, extensive local radiation therapy (external beam and proton beam), and cytotoxic chemotherapy had little impact. Tamoxifen, however, may have slowed tumor growth.

CONCLUSION

Tamoxifen may have efficacy in the treatment of prolactin-secreting pituitary carcinomas.

Gonadotropic pituitary carcinoma: case report

A 37-year-old man developed multiple intracranial, intraspinal, and general metastases from an invasive nonfunctioning pituitary adenoma after surgery and radiation therapy. This is the first gonadotropic pituitary carcinoma reported in literature.

Case report: multiple intra-cranial metastases from a prolactin-secreting pituitary tumour

Only seven cases of metastatic prolactin-secreting pituitary tumour have been reported in world literature. The metastases were intra-cranial in five cases and extra-cranial in two cases. We report a further case with multiple intra-cranial metastases in the supra-tentorial compartment. Histologically, both primary and metastatic tumours were benign with strongly positive immuno-histochemical staining for prolactin. Our case exemplifies the inconsistent correlation between the histopathological appearance and biological behaviour of malignant pituitary tumours.

Intracranial dissemination of pituitary adenoma. Case report and review of the literature

Leptomeningeal dissemination of pituitary adenoma is a very rare occurrence. The present report describes the case of a 28 year old man with a nonfunctioning pituitary adenoma which was operated on and irradiated. Eight years later, the patient developed Cushing's syndrome and multiple leptomeningeal masses were revealed by brain CT and MNR. The diagnosis was ACTH-cell adenoma, without malignant histological signs. The growth fraction of the tumor, detected by means of the immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA), was 5.45% of cells; this figure is higher than that reported for non-recurrent pituitary adenomas. From a review of the reported cases, the possibility of predicting late malignant behaviour is discussed. The microscopic aspect has no prognostic value, since metastasizing cases are not overtly malignant in a histological or cytological sense. The application of methods aimed at detecting the growth fraction of the tumor may prove useful in the early identification of aggressive pituitary tumors.

Cervical lymph nodes metastases from a pituitary carcinoma

The authors report a case of a pituitary carcinoma which was locally invasive and which metastasized to cervical lymph nodes more than 9 years after the initial presentation. Cells from the tumour and metastasis immunostained with antibodies to prolactin and growth hormone, even though there was no clinical or biochemical evidence that the tumour was secreting prolactin or growth hormone. In addition, ultrastructural studies showed a monomorphic tumour with secretory granules much smaller than those normally associated with prolactin and growth hormone secretion. The clinical and pathological features suggest that the tumour is probably an acidophil stem cell adenoma, which although known to be aggressive in its clinical behaviour has not been previously reported to metastasize.

Prolactinomas in men masquerading as invasive skull base tumours

Four giant prolactin-secreting tumours invading the skull base are described. All of them occurred in men. The presenting features were sufficiently diverse to be clinically misleading. We advocate the estimation of prolactin levels before embarking on complicated skull base surgery in men where doubt remains regarding the diagnosis after clinical and radiological study.

Dopaminergic resistance in a case of invasive macroprolactinoma

Invasive prolactinoma is a relatively infrequent variety of macroprolactinoma characterized by a fast and aggressive growth, with infiltration to adjacent structures, and whose management is frequently difficult. We present the case of a fatal invasive macroprolactinoma in whom resistance to different dopaminergic drugs developed.

Intracranial dissemination of a macroprolactinoma

A patient with a macroprolactinoma and extrasellar extension was treated by incomplete transfrontal surgery, external irradiation and additional bromocriptine (Br) treatment. After 4 years, partial bromocriptine resistance developed (a rare occurrence) together with the appearance of intracranial metastases. 123I-Iodobenzamide was helpful in evaluating the dopamine D2 receptor status of the metastatic tumour both in vivo using single-photon emission computed tomography (SPECT) and in vitro. Prolactin release by the cultured metastatic tumour cells was more potently inhibited by CV 205-502 than by bromocriptine. The patient, treated by surgery, irradiation and CV 205-502, developed a ptosis of the left eye and a transient psychiatric delusional state, the latter probably an effect of the dopamine agonist. As the right frontal metastasis was markedly positive on SPECT with 111In-SMS, somatostatin treatment was added to the CV 205-502.

Malignant prolactinoma with extracranial metastases: a report of three cases

OBJECTIVE

Prolactin-secreting tumours of the pituitary almost never metastasize extracranially. However, we have recently seen three such patients, whose presentation, clinical course and response to treatment are reviewed in order to determine whether they possess unique clinical features, and to assess optimum therapy.

DESIGN AND PATIENTS

Three patients with extracranial metastases from prolactinomas have been retrospectively reviewed.

MEASUREMENTS

Clinical courses, biochemical parameters and imaging modalities (CT, MR and radiolabelled somatostatin analogue scanning) and histopathology were assessed before and during different therapeutic regimens.

RESULTS

All three patients' presentations were initially unremarkable, but later each had persistent and relentlessly increasing serum prolactin concentrations and evidence of distant spread of their tumours. The first patient presented aged 32 and was treated with repeated transsphenoidal resections of the tumour, pituitary radiotherapy, high dose bromocriptine therapy, the somatostatin analogue octreotide and chemotherapy. Nine years after the original diagnosis a liver biopsy revealed carcinoma cells positively immunostaining for prolactin. At autopsy further microscopically similar metastases were seen in both lungs and the left hilar lymph nodes. The second patient presented aged 48 and was treated with external beam pituitary radiotherapy, bromocriptine, transsphenoidal hypophysectomy and chemotherapy. Fifteen years after the original diagnosis bone biopsy revealed carcinoma cells positively immunostaining for prolactin; the patient developed interstitial nephritis and died in renal failure. The third patient presented aged 48 with hypogonadism and bitemporal hemianopia due to a macroadenoma. This was removed transfrontally and followed by external beam radiotherapy. After recurrence, further surgery and radiotherapy were undertaken, but the tumour continued to grow and the patient died suddenly of a pulmonary embolus. At autopsy, tumour was found in thoracic lymph nodes and lung capillaries.

CONCLUSIONS

These three patients may be added to the previous two reported cases of malignant prolactinoma with extracranial spread. Several different therapies were tried but were of limited value in controlling the progression of the disease, although chemotherapy is an important modality to be considered. No particular factor or combination of factors at presentation differentiated these patients from more typical patients whose disease is much less aggressive.

Prolactin secreting pituitary carcinoma

A man with a prolactin secreting pituitary carcinoma was treated by surgery and radiotherapy. Persistent hyperprolactinaemia partially responded to oral bromocriptine for four years. Serum prolactin then rose considerably with rapid, invasive tumour recurrence. Cytotoxic chemotherapy halted tumour progression for twelve months before fatal spread throughout the brain. Failure to normalise serum prolactin with bromocriptine may precede an aggressive course in patients with prolactinoma.

Prolactin-producing pituitary carcinoma with pulmonary metastases

Pituitary adenomas rarely are metastatic. Extracranial visceral metastases of prolactinomas were not previously reported. The authors report a case of a 34-year-old man with a prolactin-producing pituitary carcinoma and histologically proven lung metastases. Pathologic examination of the pulmonary spread included electron microscopy and immunohistochemistry; these confirmed prolactin production by the tumor. The patient's presentation at initial diagnosis, disease recurrence, clinical course, management, and response to therapy (with its theoretic basis) are detailed. Despite the use of dopamine analogues (to tolerance and in combination), there was documented intracranial and extracranial disease progression. Possible future therapeutic maneuvers are discussed.

Giant invasive prolactinomas

Two of the largest prolactinomas ever documented that have been followed for nine and 10 years, respectively, demonstrate how aggressive prolactinomas may become and how difficult invasive prolactinomas are to treat. One of these prolactinomas invaded both internal auditory canals and simultaneously grew inferiorly, reducing the bony support of the skull and necessitating the patient to utilize both hands to hold his head up. The second patient's prolactinoma invaded the sphenoidal, ethmoidal, and cavernous sinuses. Both of these patients had neurosurgical debulking of their tumors followed by radiation therapy. Neither patient's prolactin levels decreased significantly during their first five years post-surgically, at which time bromocriptine was added. Since then, there has been a gradual lowering of serum prolactin levels and a decrease in the size of these tumors. These cases demonstrate that prolonged treatment and very large doses of bromocriptine may be necessary for tumor reduction in patients with invasive prolactinomas.

Subarachnoid dissemination of a pituitary adenoma

The authors present an unusual case of a pituitary adenoma that developed into intracranial and intraspinal dissemination following intracranial surgery with adjunctive radiation, and review metastasis of pituitary adenomas in the central nervous system briefly in light of other reported cases.

Discordant responses of prolactinoma to two different dopamine agonists

A 19-year-old woman presented with headaches, temporal lobe epilepsy and primary amenorrhoea. There was a family history of multiple endocrine adenomatosis. Investigation revealed normal visual fields and acuity, hyperprolactinaemia (48 000 mU/l) and a very large pituitary tumour with extrasellar spread. Treatment with bromocriptine reduced the tumour size and the prolactin level to 2440 mU/l. Six months after the start of therapy, resistance to bromocriptine developed and the prolactin concentration progressively rose to pretreatment levels, despite increasing the dose of bromocriptine to 40 mg/d. At this stage treatment with a second dopamine agonist, pergolide, was effective in reducing the prolactin concentration to normal within four months. Serial CT scans at 1, 6 and 12 months on dopamine agonist therapy showed a progressive decrease in tumour size, which seemed to be maintained even during the period of rising prolactin concentrations due to bromocriptine resistance. This case illustrates that during dopamine agonist therapy a discrepancy may exist in the clinical response as judged by reduction in tumour size and decrease in the circulating prolactin level. Furthermore, in patients with prolactinomas, pergolide may induce a response when resistance to bromocriptine develops.