Transsphenoidal microsurgery for pituitary tumors associated with hyperprolactinemia

Application of a Minimally Invasive Liposuction Technique for Harvesting Fat during Transsphenoidal Surgery: A Technical Note

Secure reconstruction in transsphenoidal surgery (TSS) is important for the prevention of the major and serious complication of postoperative cerebrospinal fluid (CSF) leak. Although abdominal fat can be safely and effectively used as a reconstruction tissue, harvesting it from the abdominal wall is traumatic and invasive, resulting in cosmetic problems. In this report, we present a method of harvesting abdominal fat using a minimally invasive liposuction technique to avoid cosmetic issues. Since 2016, we have been using fat harvested from the abdominal wall by suctioning with a dedicated syringe for reconstruction after TSS in selected cases. The liquefied fat obtained by the liposuction technique was wrapped with an oxycellulose sheet and changed its form to what we termed “fatty candy”. In this form, the fat maintained its configuration and could be handled almost as easily as a conventional fat graft. In our experienced series, there was no case with wound complication nor postoperative or late-onset CSF leak during a postoperative follow-up of at least 3 months. The fat harvested by this simple and minimally invasive liposuction technique can be expected to provide an autologous graft that is adequate not only for prevention of cosmetic problems but also for prevention of postoperative CSF leak.

Time Course of Resolution of Hyperprolactinemia After Transsphenoidal Surgery Among Patients Presenting with Pituitary Stalk Compression

BACKGROUND

Primary lactotroph disinhibition, or stalk effect, occurs when mechanical compression of the pituitary stalk disrupts the tonic inhibition by dopamine released by the hypothalamus. The resolution of pituitary stalk effect-related hyperprolactinemia postoperatively has not been studied in a large cohort of patients. We performed a retrospective review to investigate the time course of recovery of lactotroph disinhibition after transsphenoidal surgery.

METHODS

Medical records were retrospectively reviewed for all patients undergoing transsphenoidal surgery with the senior author from April 2008 to November 2014.

RESULTS

Of 556 pituitary adenomas, 289 (52.0%) were eliminated: 77 (13.9%) had an immunohistochemically confirmed prolactinoma, 119 (21.4%) patients had previous surgery, 93 (16.7%) had incomplete medical records, leaving 267 patients (48.0%) for final analysis. Of these patients, 72 (27.0%) had increased serum prolactin levels (≥23.3 ng/mL), suggestive of pituitary stalk effect (maximum prolactin level = 148.0 ng/mL). Patients with stalk effect were more likely than those with normal serum prolactin levels to present with menstrual dysfunction (29.7% vs. 19.4%; P < 0.01) and galactorrhea (11.1% vs. 2.1%; P < 0.01). Patients with lactotroph disinhibition were more likely to harbor macroadenomas than were patients who did not show lactotroph disinhibition (81.9% vs. 70.2%; P = 0.06). Among patients with increased preoperative prolactin, 77.8% experienced normalization of serum prolactin postoperatively, galactorrhea improved in 100%, sexual dysfunction resolved in 66.6%, and menstrual dysfunction among premenopausal females normalized in 73.3% at last follow-up (mean, 5.35 years; range, 0.1-10 years).

CONCLUSIONS

Transsphenoidal surgery can provide durable normalization of serum prolactin levels and related symptoms caused by pituitary stalk compression-related lactotroph disinhibition.

Gonadotrope Tumors

Gonadotrope tumors arise from the gonadotropes of the adenohypophysis. These cells rarely give rise to hyperplasia, usually only in the setting of long-standing premature gonadal failure. In contrast, gonadotrope tumors represent one of the most frequent types of pituitary tumors. Despite their relatively common occurrence, the pathogenesis of gonadotrope tumors remains unknown. Effective nonsurgical therapies remain out of reach. We review the pituitary gonadotrope from the morphologic and functional perspectives to better understand its involvement as the cell of origin of a frequent type of pituitary tumor.

Aggressive Pituitary Tumors or Localized Pituitary Carcinomas: Defining Pituitary Tumors

Pituitary tumors are common and exhibit a wide spectrum of hormonal, proliferative and invasive behaviors. Traditional classifications consider them malignant only when they exhibit metastasis. Patients who suffer morbidity and mortality from aggressive tumors classified as "adenomas" are denied support provided to patients with "cancers" and in many jurisdictions, these tumors are considered curiosities that do not warrant reporting in health registries. We propose use of the term "tumor" rather than "adenoma" to align with other neuroendocrine tumors. The features that can serve as diagnostic, prognostic and predictive markers are reviewed. Clinico-pathological and radiographic classifications provide important information and to date, no single biomarker has been able to offer valuable insight to guide the management of patients with pituitary tumors.

Medical treatment of functional pituitary tumors

Medical therapy with a dopamine agonist is the most effective for treatment of a prolactin-producing adenoma and is considered as primary treatment. Surgery and pituitary radiation are reserved for patients who either do not tolerate or do not respond to a dopamine agonist drug. A somatostatin analogue is effective medical therapy for patients with acromegaly, and this is usually administered if there is persistent GH hypersecretion after surgical resection. Medical treatment for patients with Cushing's disease is directed at the adrenal glands to reduce cortisol hypersecretion. Unfortunately, there is no effective medical therapy to reduce pituitary corticotropin production. Medical therapy for a gonadotrope adenoma with a dopamine agonist or somatostatin analogue has limited utility but is employed in patients who are unable to undergo surgery and may delay or prevent additional tumor growth. Many patients with a pituitary adenoma can be successfully treated with one treatment, either a dopamine agonist for a prolactinoma or surgery for other types of tumors. A substantial number of patients require multimodality therapy, however, including medical therapy, surgery, and pituitary radiation. Because the biologic behavior of pituitary adenomas varies considerably, a patient with a pituitary adenoma requires lifelong regular monitoring for hormone hypersecretion, tumor recurrence, and development of new pituitary hormone deficiency. A coordinated plan of care among endocrinologists, neurosurgeons, neuroophthalmologists, and radiation therapists is necessary to provide optimal care for these patients.

Comparison of endonasal endoscopic surgery and sublabial microsurgery for prolactinomas

BACKGROUND

Endonasal endoscopy is a promising minimally invasive surgery for the treatment of pituitary adenomas; it is also a good alternative to traditional sublabial microsurgery. In this study, we compared endoscopic surgery with microsurgery and evaluated both for their safety and effectiveness. We chose prolactinomas for study because their hormone and symptomatic changes facilitated the comparison.

METHODS

During the past five years, 44 randomized prolactinoma patients underwent pituitary adenomectomy. Group A (22 patients) underwent endonasal endoscopic surgery for prolactinomas. Group B (22 patients) underwent sublabial transsphenoidal microsurgery for prolactinomas.

RESULTS

In groups A and B, patients with prolactinoma exhibited significantly reduced postoperative prolactin levels, return of menstrual cycle, and relief of galactorrhea, (Wilcoxon signed rank test) (p < 0.001). But there were no statistically significant differences in the effectiveness of the procedures used in group A and group B. Visual improvement in cases of macroadenoma was satisfactory in both groups. Hospital stay in group A ranged from 2-5 days, with a mean of 3.2 days. Hospital stay in group B ranged from 4-8 days with a mean of 5.3 days. The hospital stay for group A patients was shorter (2.1 days) than for group B (Student t test, p < 0.05). The operative time was shorter by 1 hour in Group A (mean: 1.7 hours vs. mean: 2.7 hours, p < 0.05). There were fewer complications in group A (4.5%) than in group B (27%), p < 0.05.

CONCLUSIONS

The endoscopic era of pituitary surgery may be coming. Endonasal endoscopic surgery may have the same effectiveness as traditional microsurgery. However, endoscopic surgery may shorten hospital stay and operative time, and lead to fewer complications. It seems to be a good minimally invasive surgical technique for prolactinomas.

Initial clinical results of LINAC-based stereotactic radiosurgery and stereotactic radiotherapy for pituitary adenomas

PURPOSE

To retrospectively evaluate the initial clinical results of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) for pituitary adenomas with regard to tumor and hormonal control and adverse effects of the treatment.

SUBJECTS AND METHODS

Forty-eight patients with pituitary adenoma who underwent SRS or SRT between September 1989 and September 1995 were analyzed. Of these, 18 received SRS and 30 received SRT. The median tumor volumes were 1.9 cm3 for SRS and 5.7 cm3 for SRT. Eleven of the SRS and 18 of the SRT patients were hormonally active at the time of the initial diagnosis. Four of the SRS and none of the SRT patients had a history of prior radiation therapy. Both SRS and SRT were performed using a dedicated stereotactic 6-MV linear accelerator (LINAC). The dose and normalization used for the SRS varied from 1000 cGy at 85% of the isodose line to 1500 cGy at 65% of the isodose line. For SRT patients, a total dose of 4500 cGy at 90% or 95% of the isodose line was delivered in 25 fractions of 180 cGy daily doses.

RESULTS

Disease control-The three year tumor control rate was 91.1% (100% for SRS and 85.3% for SRT). Normalization of the hormonal abnormality was achieved in 47% of the 48 patients (33% for SRS and 54% for SRT). The average time required for normalization was 8.5 months for SRS and 18 months for SRT. Adverse effects-The 3-year rate of freedom from central nervous system adverse effects was 89.7% (72.2% for SRS and 100% for SRT). Three patients who received SRS for a tumor in the cavernous sinus developed a ring enhancement in the temporal lobe as shown by follow-up magnetic resonance imaging. Two of these cases were irreversible and were considered to be radiation necrosis. None of the 48 patients developed new neurocognitive or visual disorders attributable to the irradiation. The incidence of endocrinological adverse effects were similar in the two groups, resulting in 3-year rates of freedom from newly initiated hormonal replacement of 78.4% (77.1% for SRS and 79.9% for SRT).

CONCLUSION

Considering the relatively high incidence of morbidity observed in the SRS group, we recommend SRT as the primary method of radiation therapy for pituitary tumors. When treating a lesion in the cavernous sinus with SRS, special attention should be paid to dose distribution in the adjacent brain parenchyma. Longer follow-up is necessary before drawing any conclusions about the advantages of these techniques over conventional external beam radiation therapy.

Surgical management of pituitary adenomas

Surgical management of pituitary adenomas continues to be a safe and effective method, suitable for a large number of patients suffering from the effects of these lesions. Frequently surgery is just part of an overall programme that includes medical management and radiation therapy as well. It is important for the physicians and the patients to understand that surgery alone may not be totally successful, but that with careful follow-up and appropriate adjunctive management, patients with pituitary tumours may live normal lives, and may enjoy reversal of the endocrine and visual problems that had been caused by their tumours. Careful study of surgically managed patients has contributed to some of the advances that have occurred in the overall management of pituitary adenomas and in our understanding of their biology, pathophysiology and pathogenesis.

Giant pituitary adenomas: role of radiotherapy

Between 1970 and 1989, 31 patients with a diagnosis of giant pituitary adenoma were referred to the London Regional Cancer Center. Giant pituitary adenoma was defined in terms of extension in excess of 40 mm from the midpoint of the jugum sphenoidale. The diagnosis was made surgically in 30 patients and clinically in one. Tumor extent and dimensions were obtained from operative reports and/or radiological scans computed tomography or magnetic resonance imaging. Mean follow-up was 8 years. Initial treatment consisted of surgery alone (4 patients), radiotherapy alone (2 patients) and combined surgery-radiotherapy (25 patients). One patient underwent a needle biopsy for histological confirmation and was grouped with the radiotherapy alone subset. Four of the six patients who received single modality treatment failed initial treatment (three surgery and one radiation). In contrast only 3 of the 25 patients treated with combined surgery-post-operative radiotherapy progressed despite the fact that all patients had gross residual disease post-operatively and that 43% of these patients received radiotherapy based on the post-operative rather than the pre-operative tumor extent. With subsequent salvage, overall tumor control amongst the 31 patients was 93.5%. Complications in general were minimal although one acromegalic patient sustained a unilateral internal capsular cerebrovascular accident year post treatment. In summary, combined modality treatment with initial surgical debulking followed by radiotherapy in the dose range of 4500-5000 cGy over 25 fractions yields tumor control rates in giant pituitary adenomas similar to those of smaller pituitary adenomas without undue morbidity.

Enlarged adenomectomy for enclosed prolactinomas: a preliminary study of 26 cases

Preliminary results obtained from 26 cases of prolactinomas less than 20 mm in diameter after treatment by enlarged adenomectomy are described. The operation consisted in removal of the adenoma, a layer of normal pituitary at the outer edge of the tumour and the pituitary capsule in contact with the sellar meninges. 24 women and 2 men were involved whose prolactin levels (PRL) were less than 200 ng/ml. All presented abnormal PRL responses to Thyrotropin releasing hormone (TRH) and Metoclopramide (MCP) tests and an absence of a nocturnal rise in the sleep cycle study. Postoperatively, three patients developed transitory diabetes insipidus and five transitory adrenal insufficiency. Gonadotropin reserve was always found normal. All 24 women resumed normal menstrual cycles and two became pregnant within one year. From a serological viewpoint, after surgery 100% of patients were found to be normal for levels of prolactin but only 85% turned to normal dynamic tests. The results of this small series of enlarged adenomectomies seem better than those obtained using selective adenomectomy, but must be confirmed with time.

[Treatment of prolactinoma]

Prolactinomas rank first in frequency among hormone-secreting pituitary adenomas, but their management remains controversial. The authors present a review of the literature concerning the various therapeutic methods used and their results. As regards microadenomas, opinions are divided since the results obtained with bromocriptine and with selective adenomectomy are about the same. As regards macroadenomas, surgery exposes to more frequent complications and above all to recurrences. The majority of authors is in favour of bromocriptine first followed, if necessary, by surgical excision. Pregnancy may accelerate the development of prolactinomas. This risk is minimal with microadenomas and more real with macroadenomas, requiring more radical treatment before pregnancy and close monitoring.

Pituitary adenoma: the efficacy of radiotherapy as the sole treatment

The management of patients with pituitary adenomas by radiotherapy alone, using modern techniques of evaluation and current standards of treatment, has not been examined. This is a retrospective review of 29 such patients with nonfunctional or prolactin secreting pituitary macroadenomas. Patients were analyzed by visual fields, hormone levels, and CT scans. All but one patient received a tumor dose of 4500 cGy in 4 to 5 weeks. The tumor was controlled in 26 of 28 (93%) patients for an observed period of 3 to 14 years. Seventeen of 21 (81%) patients with visual impairment experienced normalization or improvement, and seven of ten (70%) patients with hyperprolactinemia achieved normalization of their serum prolactin levels. Post-treatment CT scanning revealed persistent tumor in nine of 17 patients despite clinical improvement. We conclude that: (a) radiotherapy is an effective treatment for these tumors; (b) doses need not exceed 4500 cGy in 25 fractions; (c) radiation is effective for improving vision; (d) radiation can normalize hyperprolactinemia; and (e) tumor regression is variable and unrelated to observed symptom regression.

Transsphenoidal hypophysectomy in the dog. A new technique

A technique for localizing the canine hypophysis regardless of the shape or size of a dog's skull was evaluated. Using known anatomic landmarks, the approximate location of the hypophysis was estimated, and three small self-threading screws were placed as radiographic markers in the exposed sphenoid bone. A cranial sinus venogram was performed and the hypophysis was outlined by the contrast-filled cavernous sinus. A circular ostectomy was centered over the hypophysis, using the previously placed screws as reference points. The technique was evaluated in eight dogs in a nonsurvival procedure. In seven dogs, hypophysectomy was complete and the ostectomy sites were centered precisely over the hypophysis.

Management of prolactinomas associated with very high serum prolactin levels

The authors have reviewed the results of transsphenoidal microsurgical management in 69 patients with prolactin-secreting pituitary adenomas who had preoperative serum prolactin levels over 200 ng/ml. The patients were divided into three groups based on their preoperative serum prolactin levels: over 200 to 500 ng/ml (Group A); over 500 to 1000 ng/ml (Group B); and over 1000 ng/ml (Group C). The percentage of successful treatment ("control rate") was 68%, 30%, and 14%, respectively, in these three groups of patients. Based on these results, the authors offer guidelines for the management of patients with prolactin-secreting pituitary adenomas associated with exceptionally high serum prolactin levels. The surgical control rate of 68% in Group A seems to justify surgery for these patients, while primary medical care with bromocriptine is recommended for most patients with serum prolactin levels over 500 ng/ml.

The natural history of untreated microprolactinomas

The development of radioimmunoassay (RIA) for prolactin (PRL) and sensitive high-resolution computed tomography (HRCT) has resulted in documentation of large numbers of microprolactinomas (microPRL). To try to define the rate and prevalence of tumor growth, the authors performed serial HRCT scans in 38 untreated patients, an average of 31.7 months apart. In no patient, including two patients with exuberant rises in PRL, was there any evidence of subtle tumor growth. The authors conclude that the majority of patients with microPRL have a benign course, with tumor growth occurring, if at all, over a period of years.

Gradual recovery of lactotroph responsiveness to dynamic stimulation following surgical removal of prolactinomas: long-term follow-up studies

Prolactin-secreting pituitary adenomas were selectively removed through a transsphenoidal approach from 120 women. Basal serum PRL levels (measured one to six months after surgery) were normal in 96 patients and decreased appreciably but not to normal in the remaining 24 patients. Dynamics of PRL secretion were studied at three to four months in 81 patients who had normal basal PRL level. Two different patterns of response to provocative stimuli were noted in these patients. In one group (group I, n = 65), patients had greater than 100% rise in serum PRL following TRH or perphenazine (Pz) administration. However, when analyzed as a group, the mean +/- SEM incremental responses (delta PRL) to TRH and Pz in these patients (29.9 +/- 1.9, 20.4 +/- 1.5 ng/mL) were significantly less (P less than 0.005 and P less than 0.001) than those of normal women (38.8 +/- 5, 33 +/- 5 ng/mL, respectively). Nineteen of these patients were restudied 12 to 72 months after surgery. The responses to provocative stimulation at that time were improved and similar to normal women. In contrast, in the second group (n = 16) of patients (group II), the responses to stimulation with the same agents were blunted or absent and remained so during subsequent studies. Recurrence of the hyperprolactinemia was noted in 11 of the 16 patients in group II and in only two of 65 patients in group I. The daily serum PRL levels in the immediate postoperative period were higher in patients from group II than those from group I. We conclude that transsphenoidal surgery is an optimal form of therapy for patients with PRL-secreting adenomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of prolactinoma based on the results of transsphenoidal operations

Ninety-eight patients (16 male, 82 female) with prolactinomas were treated by transsphenoidal operation. The postoperative course was closely related to the tumor size and the preoperative levels of serum prolactin. In 37 (74%) of 50 patients with microadenomas, the levels of serum prolactin returned to normal postoperatively. There were 48 patients with macroadenomas; 27 of these were expansive and 21 were invasive. In 9 (33%) of the 27 patients with expansive macroadenomas, the postoperative levels of prolactin returned to normal; this was not the case in any of the 21 patients with invasive macroadenomas. Of 81 premenopausal women, 35 (43%) resumed normal menstruation postoperatively. All patients with preoperative deficits in the visual field experienced postoperative improvement. There were no postoperative deaths or serious complications in this series. Our data indicate that microprolactinomas are highly curable by transsphenoidal operation alone. In women who plan to have children, prolactinomas should be removed immediately. On the other hand, in patients with macroprolactinomas who manifest high levels of serum prolactin, initial treatment with bromocriptine should be considered because there is little hope for surgical cure and postoperative bromocriptine treatment might be necessary.

Late recurrence of surgically removed prolactinomas

The authors observed the clinical course of 24 women with surgically removed prolactinomas for a mean postoperative interval of 62 months. The frequency of late tumor recurrence and probable factors responsible for the recurrence were investigated. Hyperprolactinemia recurred in 4 of 13 patients with microadenomas (31%) 3 to 9 months after removal. In the macroadenoma group, relapse of hyperprolactinemia occurred in 10 of 11 patients (91%), an average of 26 months after the initial postoperative return to normal prolactin levels. Return of hyperprolactinemia was accompanied by radiologic evidence of tumor recurrence in all patients with macroadenoma, and in one patient with microadenoma. Of 12 tumors in which adjacent dura was available for histopathologic examination, 7 showed dural invasion. Although these seven patients had significantly higher preoperative levels of serum prolactin than the five without dural invasion, there was no significant relation between dural involvement and tumor recurrence. The probabilities of tumor recurring from multifocal adenoma or paraadenomatous lactotrope hyperplasia could not be assessed using our surgical material. The most plausible reason for the high recurrence rate of prolactinomas after apparent surgical cure, in the absence of defined anatomic abnormalities within the pituitary, is a functional abnormality of hypothalamic-pituitary control resulting from a primary hypothalamic disorder.

Long-term results in transsphenoidal removal of nonfunctioning pituitary adenomas

Little has been written about the long-term results of transsphenoidal treatment for clinically nonfunctioning pituitary adenomas. The records of 100 patients who had undergone a transsphenoidal procedure for excision of such tumors were reviewed. Immunocytology for pituitary hormones was performed in all cases. The group consisted predominantly of null-cell adenomas, although a small number of prolactinomas and gonadotropic tumors were found. The mean diameter of the tumors at the time of detection was slightly more than 2 cm. In most cases, the presenting symptoms were due to the mass effect of the tumor (that is, visual symptoms in 72 patients, hypopituitarism in 61, headache in 36, and cranial nerve disturbance other than visual loss in 10). Radiation therapy was recommended for patients in whom subtotal removal of the adenoma was expected. Six patients developed symptomatic tumor recurrence, and 10 patients demonstrated radiographic recurrence during the 48 to 100 months (mean 73.4 months) of follow-up observation. Only three of 10 deaths during the follow-up period were due to pituitary disease or treatment.

Use of DES-treated rats as an animal model for assessment of pituitary adenoma imaging agents

Prolactin (PRL) secreting pituitary adenomas are the most common type of pituitary tumors. An imaging agent which specifically localized in prolactinomas would be of considerable clinical value for both initial detection and also for monitoring the effects of dopamine agonist therapy. Tritiated spiroperidol (3HSp) was selected for initial evaluation as a possible imaging agent based on: demonstrated localization in the pituitary and demonstrated binding to human PRL-secreting tumor tissue. DES was implanted in Fischer F344 rats and induced prolactinoma formation was evidenced by increased pituitary weight, elevated serum PRL levels and by an increase in the proportion of PRL-secreting cells in the pituitary. 3HSp concentrations in pituitary and other tissues of DES-treated rats were assessed in female rats and correlation studies showed that a 5-fold increase in serum PRL was associated with a 6-fold increase in both pituitary weight and % dose/organ accumulation of 3HSp. The number of pituitary D2 receptors per mg of protein in tissue homogenates was similar in both normal and DES-treated females. A blocking study with (+)-butaclamol demonstrated a D2 receptor-mediated component to 3HSp localization. In summary, an animal model for prolactinoma was characterized. An assessment of 3HSp accumulation indicates that radiolabelled spiroperidol shows excellent potential for detecting PRL-secreting tumors of the pituitary.

Present status of neurosurgery in the treatment of prolactinomas

Our experience with prolactinomas started in 1972 and is based on about 370 patients. Of these 247 were treated surgically, about 110 underwent medical therapy and a small number of patients were observed only. In microprolactinomas prolactin-levels could be normalized in up to 80% of the patients after selective adenomectomy. However, true recurrences were observed in 16% of the patients during long-term follow-up. The operative risk is rather low. There was no mortality in this series. The rate of complications is about 1%. Medical treatment with dopamine-agonists is successful especially in women who desire pregnancy, but should only be used in small microadenomas, in order to avoid complications. In larger macroprolactinomas h extra-sellar extension in whom primary surgical removal leads to a normalization of prolactin-levels in a minority of cases only primary therapy with dopamine-agonists leads to shrinkage of the tumour mass in about two-thirds of the patients. Since the tumour mass does not disappear completely after short-term medical treatment, we favour additional surgical tumour removal instead of long-lasting administration of dopamine-agonistic drugs in higher dosages.

Intrasellar chordoma and hyperprolactinemia

An intrasellar chordoma in a patient with diplopia and hyperprolactinemia is presented. A brief review of the literature on intrasellar chordomas and the potential etiology for the hyperprolactinemia in this patient are discussed.

Effect rates of different modalities for treatment of prolactin adenomas

Results of treatment of 963 patients with prolactin adenomas described in the literature were reviewed. The patient population was stratified into four subgroups: women and men with serum prolactin levels above and below 100 ng/ml for each of the treatment modalities: transsphenoidal surgery, bromocriptine, heavy ion radiation, conventional radiation, and transsphenoidal surgery plus conventional radiation. The five largest series within each subgroup were included. Success rates and recurrence rates were calculated for: (1) reduction of tumor size, (2) normalization of serum prolactin levels, and (3) normalization of other pituitary functions. Complication rates were calculated for procedural impairment of other pituitary functions. Transsphenoidal surgery was found to be the most effective treatment for lasting control, and bromocriptine for temporary control, of prolactin adenomas. Recurrent adenomas were most effectively treated by transsphenoidal surgery if serum prolactin levels were below 100 ng/ml. If serum prolactin levels were above 100 ng/ml, bromocriptine was the most effective treatment. Heavy ion radiation, with success rates comparable to those of transsphenoidal surgery and bromocriptine, but with lower recurrence rates, may eventually prove the most effective treatment of all.

Clinical and pathological effects of bromocriptine on prolactin-secreting and other pituitary tumors

Bromocriptine inhibits prolactin secretion and causes size reduction of prolactin-secreting adenomas. The effect of the drug upon pituitary tumors other than prolactinomas is uncertain. The authors report a prospective series of 12 patients with pituitary macroadenomas in whom bromocriptine was administered for 6 weeks prior to transsphenoidal surgery. Five of the patients had computerized tomographic documentation of significant reductions in tumor size (Group A) and six had no change (Group B) during 3 and 6 weeks of bromocriptine administration. One patient who demonstrated size reduction in his tumor was not assigned to either group as he was treated with high-dose dexamethasone concurrently with the bromocriptine. Pathological examination (light and electron microscopy and immunocytochemistry) indicated that all Group A patients harbored tumors with prolactin granules whereas all Group B tumors lacked such granules. Adenoma cells in the responsive tumors were involuted with reduced cytoplasmic, nuclear, and nucleolar areas. Neither widespread cell necrosis, infarction, nor vascular injury was observed. Two of the five Group A patients discontinued bromocriptine prior to completion of the 6-week protocol and had a rapid return of their tumors to pre-treatment size. Although bromocriptine has been reported to cause shrinkage of nonfunctional tumors, there was no radiological evidence of size reduction or pathological changes in the nonfunctional tumors of this series. Interestingly, serum levels of prolactin were modestly elevated (84 and 113 ng/ml) in two of the six Group B patients, an elevation due to stalk compression rather than secretion by adenoma cells. This finding underscores the fact that failure of bromocriptine to reduce pituitary tumor size in the presence of hyperprolactinemia may occur because the tumor is other than a prolactinoma. This is the first moderate-sized group of patients in whom pathological changes in responsive prolactinomas during bromocriptine therapy have been demonstrated. As bromocriptine is not tumoricidal, and thus not curative, there is insufficient evidence to recommend this drug as primary therapy for either prolactin-secreting or nonfunctional macroadenomas, but the drug may have potential as a preoperative adjunct to effect shrinkage of prolactinomas and theoretically, at least, make excision easier and possibly more complete.

Pituitary microadenomas: surgical results and morphological findings

The results of transsphenoidal microsurgery in treating 22 patients with pituitary microadenomas are reported. Histological and ultrastructural comparative studies were performed in attempting to obtain a more accurate morphological classification of pituitary microadenomas.

Recurrence of chromophobe pituitary adenomas after operation and postoperative radiotherapy

The rate of recurrence is reported in a prospective study of 56 patients (28 men, 28 women) with large chromophobe pituitary adenoma (with or without hyperprolactinemia). The surgical approach was transfrontal in 44 and transseptosphenoidal in 12 patients. Cryoapplication was combined with the transsphenoidal operation. All but one patient received postoperative pituitary irradiation. Altogether, 11 (20%) clinical relapses (10 men) occurred between 0.5 and 6 years after the transfrontal operation. Patients that relapsed had had larger tumors than those remaining in remission. Occurrence of the tumors appeared with a deterioration of the visual field defect in 9 patients. There were no differences in the degrees of hypopituitarism in patients who relapsed as compared to patients remaining in remission.

Bromocriptine treatment of women with suspected pituitary prolactin-secreting microadenomas

The present study was designed to investigate the efficacy of bromocriptine in reducing serum prolactin (PRL) levels and in decreasing the size of PRL-secreting microadenomas. Bromocriptine, 5.0 mg, was administered daily for 2 years of 17 women who had galactorrhea, hyperprolactinemia, and hypocycloidal polytomographic evidence suggestive of a pituitary microadenoma. Serum PRL levels were normalized in 16 of 17 women during therapy. Associated with this was resumption of regular menses in 15 of 16 women with menstrual dysfunction and cessation of galactorrhea in 16 of the 17 women. Improvement in the roentgenographic appearance of the sella turcica occurred in two women. No progression in tumor size was found during the course of therapy. Side effects attributed to bromocriptine were minimal, transient, and usually well tolerated. These data suggest that bromocriptine is an appropriate therapeutic modality for PRL-secreting pituitary microadenomas.

Transsphenoidal microsurgery for prolactin-secreting pituitary adenomas

The authors present the results of transsphenoidal microsurgery in 100 women with the amenorrhea-galactorrhea syndrome caused by pituitary adenomas associated with hyperprolactinemia (prolactinomas). As the surgical results were closely related to the preoperative levels of serum prolactin, the patients were divided into two groups: patients with preoperative prolactin less than 200 ng/ml (Group 1), and those with preoperative prolactin greater than 200 ng/ml (Group 2). The results in Group 1 (72 patients) were significantly better. In this group, 56 (78%) patients regained normal menstrual cycles, and 55 (76%) had return of elevated prolactin to normal following surgery. In Group 2 (28 patients), however, only 11 (39%) resumed normal menstrual periods postoperatively, and 13 (*46%) had return of elevated prolactin levels to normal. There was good correlation between tumor size and the preoperative level of prolactin. Of the 72 women in Group 1, 58 (81%) had tumors less than 1 cm (microadenomas), whereas of the 28 women in Group 2, only four (14%) had tumors of that size. All patients with visual field deficits preoperatively improved or had a normal visual examination postoperatively; none was made worse by surgery. Four patients (three in Group 2) have required additional surgery and/or irradiation. In the last six patients of the series, contrast-enhanced coronal computerized tomography slices made with the updated General Electric scanner detected five microadenomas. Considering that a relatively high percentage of sellar polytomograms are negative in patients with proven microadenomas (that is, only 40 of 72 patients in Group 1 has abnormal polytomography), it is likely that sellar polytomography will significantly decrease in importance in the diagnostic work-up of these patients. The authors provide a rationale for transsphenoidal microsurgery in these patients as opposed to other forms of management, such as bromocriptine therapy and irradiation.

Abnormal regulation of prolactin secretion after successful surgery for prolactin-secreting pituitary tumours

Patients with prolactin-secreting pituitary tumours have a diminished prolactin (PRL) response after administration of a variety of stimulatory agents, including thyrotrophin-releasing hormone (TRH), chlorpromazine (CPZ) and insulin-induced hypoglycaemia. We examined responses to these agents in sixty-seven women with PRL-secreting tumours before and after trans-sphenoidal surgery. Twenty-nine of the women were cured as defined by restoration of normal serum PRL concentrations and resumption of regular menses. One year following trans-sphenoidal surgery, patients with normal PRL concentrations and regular menses had normal PRL responses to TRH, while the responses to CPZ and insulin hypoglycaemia were not improved. The reversible impairment of PRL response to TRH reflects suppressed function of normal PRL-secreting cells, and the persistence of abnormal PRL responses to provocative stimuli after successful tumour removal may reflect some fundamental defect in the regulation of PRL secretion in patients with PRL-secreting adenomas. When growth hormone (GH) reserve after insulin hypoglycaemia was represented as the mean absolute increment above the basal concentration and compared with normal subjects, women with PRL-secreting tumours had a diminished response that returned to normal after successful surgery. This reversible impairment of GH secretion is not adequately reflected by standard criteria for GH response and suggests that PRL may have a role in the regulation of GH secretion.

Simultaneously occurring prolactinomas. Case report

✓ The case of a patient with two separate prolactin-secreting pituitary adenomas is presented. The importance of thorough inspection of the pituitary gland at operation is emphasized.

Surgical treatment of pituitary prolactinomas: postoperative prolactin and fertility in seventy patients

The surgical results obtained in 70 patients with pituitary prolactinomas indicate that the success of surgery depends on the preoperative prolactin level and the diameter of the adenoma, and that the former is the more influential factor. Assessment of both of these parameters affords a good prediction of the endocrine result. The cure rates for different patient groups ranged from 4% to 90%. Postoperative results in women (57% with normal prolactin levels) were better than those in men (17% with normal prolactin levels). Of 19 women who desired pregnancy, 11 (58%) achieved successful pregnancies; 1 woman became pregnant twice. In addition, one woman had an extrauterine pregnancy and one suffered a spontaneous abortion. Five required additional bromocriptine therapy. The data were evaluated analytically.

Pituitary function in prolactinoma. Effect of surgery and postoperative bromocriptine therapy

Forty-five women and fifteen men with prolactinomas have been treated surgically. Patients with large tumours received pituitary irradiation and postoperative hyperprolactinaemia was treated with bromocriptine. The patients have been followed-up for 6-36 months following the operation. The tumours were larger and the levels of production higher in men as compared with women. All women had amenorrhoea. Galactorrhoea was present in forty-three women but not in the men. After surgery serum prolactin levels fell significantly in all women but remained above normal in thirty-six; prolactin remained high in twelve men. Bromocriptine effectively decreased the postoperative hyperprolactinaemia. The surgical complications were oculomotor nerve paresis in one woman and one man. After surgery six (23%) women developed impaired GH secretion, six (15%) impaired thyroid function, eight (18%) impaired cortisol secretion and five (17%) impaired LH secretion in isolation or combination which had not been present preoperatively. Three patients relapsed. Fifteen women menstruated after surgery and ten began to do so during the subsequent bromocriptine treatment. Thus, menstruation was restored in all six women with microadenomas in sixteen of twenty patients with intrasellar macroadenomas and three of nineteen patients with suprasellar adenomas. The preoperative LH-reserve proved to be an important prognostic indicator. Nine patients, i.e. 50% of patients desiring fertility became pregnant. In the men gonadal function deteriorated in four patients and did not improve in any without testosterone treatment.

Evaluation of two inhibitory tests (nomifensine and L-dopa + carbidopa) for the diagnosis of hyperprolactinaemic states

It has been reported that administration of nomifensine (Nom) or of L-dopa + carbidopa (L-dopa + Carb) potentiates central dopaminergic tonus, resulting in decreased prolactin (PRL) secretion. It has been proposed that these drugs would help to discriminate patients with PRL-secreting pituitary tumours from those with so-called 'functional' hyperprolactinaemia. In this study, oral Nom (200 mg) was given to forty-three hyperprolactinaemic patients and L-dopa + Carb (50 mg Carb every 6 h for four doses followed by L-dopa 100 mg and Carb 35 mg) to thirty of them and both treatment to ten normal subjects. The hyperprolactinaemic patients were divided into four clinical groups. Group A, twenty patients with proven PRL-secreting pituitary tumours; Group B, thirteen women with elevated PRL levels (less than 100 ng/ml) without any radiological evidence of a pituitary tumour (hyperprolactinaemia of unknown aetiology or 'functional' hyperprolactinaemia); Group C, four women with polycystic ovarian disease and mildly elevated serum PRL; Group D, six patients with various other disorders associated with hyperprolactinaemia. PRL levels decreased in the normal controls below the basal values by 61.3% +/- 6.2 (SEM) after Nom and 77.6% +/- 4.2 after L-dopa + Carb. Decreases in serum PRL of at least 50% (in three consecutive determinations) were found in group A in 20% of patients after Nom and in 25% after L-dopa + Carb; in group B in 15% and 40% of cases; in most of the hyperprolactinaemic women in group C; and some in group D. In conclusion, these two treatments did not discriminate between tumorous and non-tumorous cases of PRL hypersecretion.

A practical approach for the evaluation of women with abnormal polytomography or elevated prolactin levels

Based upon the experience gained in the evaluation of 60 patients with abnormal polytomography and/or elevated prolactin levels, the following observations can be made: Patients with amenorrhea, amenorrhea and galactorrhea, galactorrhea alone, or anovulatory cycles and infertility may or may not have pituitary tumors. Clinical symptoms do not always correlate with the prolactin level, and patients with normal prolactins may have pituitary tumors. The incidence of empty sella is significant (15.8% in this series). Visual field examination is not a useful screening procedure, but evaluation of thyroid function is important to detect the occasional patient with hypothyroidism (3.5% in this series). The insulin tolerance test is not helpful in detecting the presence of pituitary tumors or in guiding management decisions, and the CT scan contributes little and should be omitted from the evaluation process. A straightforward, economical, and efficient approach to this clinical problem is presented.

Prolactin-producing pituitary adenomas

Eight patients with amenorrhea, galactorrhea, and hyperprolactinemia underwent excision of pituitary adenomas by means of a microsurgical procedure that used a transsphenoidal approach. Prolactin values returned to normal in five of the patients and were significantly lower in three. Five patients resumed their menses. Two became pregnant. All eight patients had used oral contraceptives. The association of oral contraceptives and prolactin-producing pituitary adenomas is discussed.

Tests of prolactin secretion in diagnosis of prolactinomas

Prolactin-secreting tumours of the pituitary were identified and treated by transsphenoidal microsurgery in fourteen infertile females with hyperprolactinaemia. Resting prolactin levels were 590--9000 mU/1 (mean 3400). In seven patients, tomography of the pituitary fossa was normal and resting prolactin levels were 590-6000 mU/1 (mean 3400). In these patients the pre-operative diagnosis prolactinoma in these patients was made by demonstrating loss of the normal circadian prolactin profile and impaired prolactin response to intravenous thyrotrophin-releasing hormone (T.R.H.) and metoclopramide stimulation. Prolactin response to the acute oral administration of L-dopa and bromocriptine was of less diagnostic value. Preoperative assessment of anterior pituitary function identified abnormalities other than hyperprolactinaemia in four patients (28%). Post-operative assessment indicated that microsurgery was curative in twelve patients (86%), selective in all, and without significant side-effect. It is concluded that dynamic tests such as T.R.H. and metoclopramide stimulation have considerable value in identifying hyperprolactinaemic patients with prolactin-secreting adenomas, particularly those which are radiologically occult.