Utility of bilateral inferior petrosal sinus sampling for diagnosis and lateralization of Cushing's disease in the pediatric population: case series and review of the literature.

OBJECTS: Cushing's disease (CD) is the most common cause of ACTH-dependent hypercortisolism in children age ≥ 7. The utility of bilateral inferior petrosal sinus sampling (BIPSS), an important test in adults, is less defined in children. We present a case series of children with ACTH-dependent hypercortisolemia and review the literature to assess the utility of BIPSS in the diagnosis and localization of CD. METHODS: We performed an IRB-approved chart review of patients aged ≤ 18 with ACTH-dependent hypercortisolism at MGH between 2000 and 2019 and collected clinical, laboratory, radiographic, BIPSS, surgical, and outcomes data. RESULTS: In our cohort (n = 21), BIPSS had a sensitivity of 93% and specificity of 100% for diagnosis of CD. Compared to surgery, successful BIPSS correctly predicted adenoma laterality in 69% of cases vs. 70% by MRI. Among patients with lesions ≥ 4 mm (n = 9), BIPSS correctly lateralized in 50% vs. 100% by MRI. In patients with subtle lesions (< 4 mm, n = 7), BIPSS correctly lateralized in 80% vs. 71% by MRI. In patients (n = 4) with CD and negative MRIs, BIPSS correctly lateralized in 75% cases. Surgical cure was achieved in 90% of patients and 95% of patients had long-term disease control. CONCLUSIONS: In our cohort (n = 21; n = 20 CD, n = 1 ectopic ACTH secretion), BIPSS was sensitive and specific for the diagnosis of CD. Compared to MRI, BIPSS was not additionally helpful for lateralization in patients with lesions ≥ 4 mm on MRI. BIPSS was helpful in guiding surgical exploration and achieving immediate postoperative remission among patients with subtle and negative MRI findings.

Effects of growth hormone deficiency on body composition and biomarkers of cardiovascular risk after definitive therapy for acromegaly.

BACKGROUND: Both growth hormone (GH) excess and GH deficiency are associated with abnormalities in body composition and biomarkers of cardiovascular risk in patients with pituitary disorders. However, the effects of developing GH deficiency after definitive treatment of acromegaly are largely unknown. OBJECTIVE: To determine whether development of GH deficiency after definitive therapy for acromegaly is associated with increased visceral adiposity and biomarkers of cardiovascular risk compared with GH sufficiency after definitive therapy for acromegaly. DESIGN: Cross-sectional. PATIENTS: We studied three groups of subjects, all with a history of acromegaly (n = 76): subjects with subsequent GH deficiency (GHD; n = 31), subjects with subsequent GH sufficiency (GHS; n = 25) and subjects with active acromegaly (AA; n = 20). No study subjects were receiving somatostatin analogues, dopamine agonists or hGH. MEASUREMENTS: Body composition (by DXA), abdominal adipose tissue depots (by cross-sectional CT), total body water (by bioimpedance analysis) and carotid intima-media thickness (IMT) were measured. Fasting morning serum was collected for high-sensitivity C-reactive protein (hsCRP), lipids and lipoprotein levels. An oral glucose tolerance test was performed, and homoeostasis model of assessment-insulin resistance (HOMA-IR) was calculated. RESULTS: Abdominal visceral adipose tissue, total adipose tissue and total body fat were higher in subjects with GHD than GHS or AA (P < 0·05). Subcutaneous abdominal fat was higher, and fibrinogen and IMT were lower in GHD (but not GHS) than AA (P < 0·05). Patients with GHD had the highest hsCRP, followed by GHS, and hsCRP was lowest in AA (P < 0·05). Fasting glucose, 120-min glucose, fasting insulin, HOMA-IR and per cent total body water were lower in GHD and GHS than AA (P < 0·05). Triglycerides were higher in GHS than AA (P < 0·05). Lean body mass, mean arterial pressure, total cholesterol, HDL and LDL were comparable among groups. CONCLUSIONS: Development of GHD after definitive treatment of acromegaly may adversely affect body composition and inflammatory biomarkers of cardiovascular risk but does not appear to adversely affect glucose homoeostasis, lipids and lipoproteins, or other cardiovascular risk markers.

Treatment of adrenocorticotropin-dependent Cushing's syndrome: a consensus statement.

OBJECTIVE: Our objective was to evaluate the published literature and reach a consensus on the treatment of patients with ACTH-dependent Cushing's syndrome, because there is no recent consensus on the management of this rare disorder. PARTICIPANTS: Thirty-two leading endocrinologists, clinicians, and neurosurgeons with specific expertise in the management of ACTH-dependent Cushing's syndrome representing nine countries were chosen to address 1) criteria for cure and remission of this disorder, 2) surgical treatment of Cushing's disease, 3) therapeutic options in the event of persistent disease after transsphenoidal surgery, 4) medical therapy of Cushing's disease, and 5) management of ectopic ACTH syndrome, Nelson's syndrome, and special patient populations. EVIDENCE: Participants presented published scientific data, which formed the basis of the recommendations. Opinion shared by a majority of experts was used where strong evidence was lacking. CONSENSUS PROCESS: Participants met for 2 d, during which there were four chaired sessions of presentations, followed by general discussion where a consensus was reached. The consensus statement was prepared by a steering committee and was then reviewed by all authors, with suggestions incorporated if agreed upon by the majority. CONCLUSIONS: ACTH-dependent Cushing's syndrome is a heterogeneous disorder requiring a multidisciplinary and individualized approach to patient management. Generally, the treatment of choice for ACTH-dependent Cushing's syndrome is curative surgery with selective pituitary or ectopic corticotroph tumor resection. Second-line treatments include more radical surgery, radiation therapy (for Cushing's disease), medical therapy, and bilateral adrenalectomy. Because of the significant morbidity of Cushing's syndrome, early diagnosis and prompt therapy are warranted.

Effects of testosterone replacement in androgen-deficient women with hypopituitarism: a randomized, double-blind, placebo-controlled study.

CONTEXT: Hypopituitarism in women is characterized by profound androgen deficiency due to a loss of adrenal and/or ovarian function. The effects of testosterone replacement in this population have not been reported. OBJECTIVE: The objective of the study was to determine whether physiologic testosterone replacement improves bone density, body composition, and/or neurobehavioral function in women with severe androgen deficiency secondary to hypopituitarism. DESIGN: This was a 12-month randomized, placebo-controlled study. SETTING: The study was conducted at a general clinical research center. STUDY PARTICIPANTS: Fifty-one women of reproductive age with androgen deficiency due to hypopituitarism participated. INTERVENTION: Physiologic testosterone administration using a patch that delivers 300 microg daily or placebo was administered. MAIN OUTCOME MEASURES: Bone density, fat-free mass, and fat mass were measured by dual x-ray absorptiometry. Thigh muscle and abdominal cross-sectional area were measured by computed tomography scan. Mood, sexual function, quality of life, and cognitive function were assessed using self-administered questionnaires. RESULTS: Mean free testosterone increased into the normal range during testosterone administration. Mean hip (P = 0.023) and radius (P = 0.007), but not posteroanterior spine, bone mineral density increased in the group receiving testosterone, compared with placebo, as did mean fat-free mass (P = 0.040) and thigh muscle area (P = 0.038), but there was no change in fat mass. Mood (P = 0.029) and sexual function (P = 0.044) improved, as did some aspects of quality of life, but not cognitive function. Testosterone at physiologic replacement levels was well tolerated, with few side effects. CONCLUSIONS: This is the first randomized, double-blind, placebo-controlled study to show a positive effect of testosterone on bone density, body composition, and neurobehavioral function in women with severe androgen deficiency due to hypopituitarism.

Accelerated HER-2 degradation enhances ovarian tumor recognition by CTL. Implications for tumor immunogenicity.

We investigated the ubiquitination and degradation of a tumor antigen, the HER-2/neu (HER-2) protooncogene product which is overexpressed in epithelial cancers. HER-2 degradation was investigated in the ovarian tumor line, SKOV3.A2, that constitutively overexpressed long-life HER-2. We used as agonist geldanamycin (GA), which initiated downmodulation of HER-2 from the cell surface. HER-2 was polyubiquitinated and degraded faster in the presence than in the absence of GA. GA did not decrease HLA-A2 expression. Presentation of the immunodominant cytotoxic T lymphocyte (CTL) epitope, E75 (369-377) from SKOV.A2 was inhibited by proteasome inhibitors, such as LLnL but was enhanced by cysteine protease inhibitors such as E64, indicating that both the proteasome and cysteine proteases are involved in epitope formation but have different effects. Enhanced tumor recognition was not an immediate or early effect of GA treatment, but was evident after 20 h of GA treatment. In contrast, 20 h GA treatment did not increase tumor sensitivity to LAK cell lysis. Twenty hour GA-treated SKOV3.A2 cells expressed an unstable HER-2 protein synthesized in the presence of GA, of faster electrophoretic mobility than control HER-2. This suggested that the newly synthesized HER-2 in the presence of GA was the main source of epitopes recognized by CTL. Twenty hour GA-treated SKOV3.A2 cells were better inducers of CTL activity directed to a number of HER-2 CTL epitopes, in peripheral blood mononuclear cells compared with control untreated SKOV3.A2 cells. Thus, induction of HER-2 protein instability enhanced the sensitivity of tumor for CTL lysis. Increased HER-2 CTL epitopes presentation may have implications for overcoming the poor immuno-genicity of human tumors, and design of epitope precursors for cancer vaccination.

Pedicled rhinotomy for clival chordomas invaginating the brainstem.

OBJECT: Clival chordomas are frequently midline lesions whose posterior growth may breach the dura and invaginate the brainstem. This precludes safe delivery of potentially curative high-dose fractionated proton radiotherapy. To avoid this problem, the authors performed pedicled rhinotomy to resect chordomas in 10 patients. METHODS: Pedicled rhinotomy is a midface transnasal route to the intercarotid sella and clivus from the tuberculum sellae to the mid-C-2 level. It involves a lateral rhinotomy incision, osteotomies of nasal bones and cartilage, lateral rotation of the nose, removal of the nasal septum and medial maxillary walls, opening of ethmoid and sphenoid sinuses, and dissection of nasopharynx and oropharynx to expose the clivus and craniovertebral junction. Tumors involving the sella, medial cavernous sinuses, middle and lower clivus, and C-1 arch and dens can be removed even if they traverse the dura. Closure involves dural repair, grafting of fat and split-thickness skin, rotation of a vascularized mucosal pedicle, and reattachment of nasal cartilage. Ten clival chordomas in adult patients were surgically removed via a pedicled rhinotomy approach. Seven patients had previously undergone a total of nine skull base procedures. In eight of the 10 patients, tumors compressing the brainstem were completely removed using this technique. One patient required an additional subtemporal resection of a suprasellar tumor before definitive radiotherapy could be undertaken. No patient sustained any new neurological deficit; in eight patients headache, diplopia, or hemiparesis improved. One patient developed postoperative cerebrospinal fluid leakage and meningitis that were successfully treated with antibiotic agents and shunt placement. CONCLUSIONS: Pedicled rhinotomy provides excellent shallow-field exposure of midline clival chordomas and permits relief of brainstem compression and the postoperative administration of potentially curative proton beam irradiation.

Activin effects on neoplastic proliferation of human pituitary tumors.

Factors underlying growth regulation in human pituitary tumors are largely unknown. Activin functions as an antiproliferative cytokine in a number of cell types and is endogenously expressed in normal and neoplastic human pituicytes. We investigated the effect of activin on proliferation in 16 clinically nonfunctioning pituitary adenomas in primary culture. Treatment for 24 h with activin (0-10 ng/mL) significantly inhibited cell proliferation in 5 tumors (P < 0.05), as determined by [3H]thymidine incorporation. In 9 tumors, we studied regulation of the cyclin-dependent kinase inhibitor p21WAF1/cip1 as a potential activin mediator. In tumors with activin-inhibited proliferation, p21WAF1/cip1 gene expression was up-regulated after 4 h in a dose-dependent manner (0-100 ng/mL). We also investigated tumor expression of follistatin messenger ribonucleic acid, an activin-binding protein with two isoforms of different potencies. In contrast to normal pituitary tissue, only four tumors expressed both follistatin isoforms, and three tumors expressed only the less potent form. Tumors in which activin induced antiproliferative responses showed diminished or no follistatin messenger ribonucleic acid expression compared to normal pituitary. These data indicate that activin has an antiproliferative effect in a subgroup of human pituitary tumors.

Expression of prolactin-releasing peptide and its receptor messenger ribonucleic acid in normal human pituitary and pituitary adenomas.

The recently identified PRL-releasing peptide (PrRP) is the first hypothalamic peptide hormone that specifically stimulates PRL production from the pituitary gland. Similar to other hypothalamic regulatory hormones, it acts through its specific seven-transmembrane domain, G protein-coupled receptor. Using RT-PCR, we examined messenger ribonucleic acid (mRNA) expression of PrRP and its receptor in normal human pituitary tissue and in pituitary tumors. PrRP mRNA was expressed in all five normal pituitary glands examined. In contrast, PrRP mRNA was detected in only 5 of 11 of the human prolactinomas. All 5 prolactinomas expressing PrRP were responsive to dopamine agonist treatment, whereas PrRP-negative prolactinomas were non- or partially responsive. PrRP mRNA was also detected in 6 of 13 GH-secreting tumors and 5 of 10 clinically nonfunctioning tumors investigated. PrRP receptor mRNA was found in all the normal and neoplastic human pituitary samples studied. The production of PrRP and its receptor by normal and neoplastic pituitary tissue raises the question of whether it may regulate PRL production in an autocrine/paracrine manner in pituitary tissue. Further investigation of PrRP and its receptor expression and function will be needed to clarify its potential role in regulating PRL secretion in normal human lactotrophs and pituitary tumors.

Long-term mortality after transsphenoidal surgery for Cushing disease.

BACKGROUND: Untreated Cushing disease historically has a high mortality rate, but the long-term survival of patients with Cushing disease after transsphenoidal surgery has not been reported. OBJECTIVE: To determine long-term mortality rate in patients who are treated for Cushing disease with current management techniques. DESIGN: Retrospective case series. SETTING: Tertiary care center. PATIENTS: 161 patients (32 men and 129 women; mean age, 38 years) who were treated for Cushing disease between 1978 and 1996. INTERVENTION: Transsphenoidal adenomectomy and as-needed adjunctive therapy. MEASUREMENT: Record review with follow-up interview. RESULTS: The cure rate for patients with microadenomas who had no previous therapy was 90% (123 of 137). No perioperative deaths occurred (0 of 193 procedures [95% CI, 0.0% to 1.9%]). Follow-up data (mean, 8.7 years) were obtained for 99% of patients (159 of 161). Six patients died. The 5- and 10-year survival rates were 99% (CI, 97% to 100%) and 93% (CI, 88% to 99%), respectively. Survival was similar to that seen in an age- and sex-matched sample that was based on U.S. population data (standardized mortality ratio, 0.98 [CI, 0.44 to 2.2]; P > 0.2). CONCLUSION: Survival of patients treated for Cushing disease with current management techniques between 1978 and 1996 was better than the poor survival historically associated with this disorder.

Mutational analysis of activin/transforming growth factor-beta type I and type II receptor kinases in human pituitary tumors.

Genetic mutation or loss of activin/transforming growth factor-beta (TGFbeta) receptor function has been shown in human lymphoid, breast, and colorectal tumors as well as Hep2B and Mv1Lu cell lines. Although activin stimulates FSHbeta biosynthesis and secretion, a large percentage of human gonadotroph tumors have previously been demonstrated to be nonresponsive to characterized activin effects. This phenotype may be indicative of loss of functional cell surface receptors and/or intracellular signaling mediators of activin responses. Several studies examining the structure/function of type I and II receptors specific for ligands in the TGFbeta superfamily have delineated the critical regions for receptor intracellular kinase function. In the case of TGFbeta, inactivating mutations in these regions have been shown to render these receptors kinase deficient by a dominant negative phenotype and result in resistance to growth arrest. We therefore hypothesized that activin/TGFbeta cell surface receptors may act as tumor suppressors in human pituitary tumors, and that inactivating genetic mutations in the intracellular kinase region of this gene family may release pituicytes from normal growth suppression by activin through a similar mechanism. We used single stranded conformational polymorphism analysis to examine 2 intracellular regions required for type I receptor signaling by human Alk1-5 type I receptors as well as the entire coding region of 2 activin type II receptors and the TGFbeta type II receptor in 64 human pituitary tumors. A novel polymorphism was found in 45% of tumors at codon P117 of the ActRIIA gene and was used as a positive control for single stranded conformational polymorphism. One patient with a gonadotroph tumor had a confirmed A482V germline mutation in the Alk1 gene within kinase subdomains X-XI. No other mutations were detected in any tumor studied. These data suggest that somatic mutations within these intracellular kinase regions of type I/type II receptors are rare in human pituitary tumors.

Salmeterol compared with current therapies in chronic asthma.

BACKGROUND: Therapy with salmeterol, a long-acting, selective, inhaled beta 2-adrenergic agonist, is effective and safe for patients with persistent asthma; however, few long-term studies comparing salmeterol with current combination treatment regimens have been reported. METHODS: A multicenter, randomized, placebo-controlled, double-blind study was conducted in 386 patients over 41 to 46 weeks in 27 medical centers (two thirds of the investigators were primary care physicians). Patients were randomized to receive either salmeterol or placebo, and further randomized to weaning or nonweaning from current asthma therapies (except inhaled corticosteroids). Treatment groups were: salmeterol/weaning (S + W), placebo/weaning (P + W), salmeterol/no weaning (S + NW), and placebo/no weaning (P + NW). Attempts at active weaning were carried out at the discretion of the investigator for 2 to 6 weeks. Pulmonary function, albuterol use, and asthma symptoms were measured. RESULTS: The clinical benefits of salmeterol occurred despite weaning off existing nonsteroidal asthma medications. The mean morning peak expiratory flow rate was significantly increased in the S + W group (32.3 L/min) compared with both the P + W (4.9 L/min) and P + NW (6.8 L/min) groups (P < .001). Compared with the P + W and P + NW groups, the S + W group experienced significant (P < .05) improvements in overall mean asthma symptom scores, mean number of puffs of supplemental albuterol, the percentage of days with no supplemental albuterol use, and the mean number of awakenings caused by asthma (except for the P + NW comparison, P = .090). No significant differences were noted between treatment groups in any safety evaluation, including 12-lead electrocardiograms. CONCLUSIONS: The addition of salmeterol in the treatment of persistent asthma resulted in sustained improvement in pulmonary function and symptoms. The long-term use of salmeterol is safe and improves the clinical course and stability of asthma following reductions in nonsteroidal asthma therapy.

Long-term mortality after transsphenoidal surgery and adjunctive therapy for acromegaly.

To analyze the long term outcome after multimodality therapy for acromegaly, a retrospective review was performed on 162 patients who underwent transsphenoidal surgery at Massachusetts General Hospital between 1978 and 1996. The surgical cure rate for microadenomas was 91%, that for macroadenomas was 48%, and it was 57% overall. The surgical cure rate was significantly dependent on tumor size, but was not dependent on age or sex. An improvement in the surgical cure rate was noted over the course of the review, from 45% before 1987 to 73% since 1991. Long term follow-up was obtained in 99% of U.S. residents (149 of 151), with a mean follow-up period of 7.8 yr. Adjuvant radiation and/or pharmacological therapy was given to 61 patients. Of the entire group, 83% (124 of 149) were in biochemical remission as determined by normalization of serum insulin-like growth factor I levels or by GH suppression after oral glucose tolerance testing at last contact or at death. The recurrence rate was 6% at 10 yr and 10% at 15 yr after surgery in those patients who initially met the criteria for surgical cure. The 10-yr survival rate was 88%, and there were 12 deaths at postoperative intervals of 2-12 yr, with the most common cause of death being cardiovascular disease. A Cox proportional hazards model showed that patient-years with persistent disease carried a 3.5-fold [95% confidence interval (CI), 1.0-12; P = 0.02] relative mortality risk compared to those patient-years in remission. A Poisson person-years regression analysis showed no significant difference in survival between those 86 patients cured at operation and an age- and sex-matched sample from the U.S. population [standardized mortality ratio (SMR), 0.84; 95% CI, 0.3-2.2; P = 0.35]. A similar analysis on the entire group of 149 patients showed no significant difference in survival from that in a control sample (SMR, 1.16; 95% CI, 0.66-2.0; P = 0.3). Mortality risk for patient-years with persistent active disease after unsuccessful treatment vs. that in the U.S. population sample remained increased (SMR, 1.8; 95% CI, 0.9-3.6; P = .05). This analysis suggests that the decreased survival previously reported to be associated with acromegaly can be normalized by successful surgical and adjunctive therapy.

Differential expression of estrogen receptor-beta (ER beta) in human pituitary tumors: functional interactions with ER alpha and a tumor-specific splice variant.

The mitogenic and regulatory effects of estrogen (E2) in adenohypophysial cells are known to be mediated through the nuclear estrogen receptor (ER alpha). Expression of ER alpha and several of its messenger ribonucleic acid (RNA) alternate splice variants has been shown to be restricted to prolactinomas and gonadotroph tumors. However, little is known about gene expression patterns of the novel nuclear hormone receptor ER beta in the neoplastic pituitary. ER beta has high homology to ER alpha in the DNA- and ligand-binding domains, but encodes a distinct transcriptional activating function-1 (AF-1) domain. Using RT-PCR analysis of total RNA from 38 human pituitary adenomas, we found that ER beta messenger RNA was coexpressed with ER alpha and its splice variants in 60% of prolactinomas, 100% of mixed GH/PRL tumors, and 29% of gonadotroph tumors. ER beta gene expression was not limited to ER alpha-positive tumor subtypes, however, and was also found in 100% of null cell tumors, 80% of somatotroph tumors, and 60% of corticotroph tumors. Because ER beta is coexpressed with ER alpha and its splice variants in prolactinomas and gonadotroph tumors, we functionally characterized the potential interactions between ER beta and ER alpha. We also examined the potential cooperative effects on ER beta-mediated gene expression of a tumor-specific truncated delta 5ER alpha splice variant that has been shown to be coexpressed in the majority of ER alpha-positive tumors. This exon 5 splice variant encodes the AF-1 domain as well as regions critical for DNA binding and nuclear localization, but lacks the ligand-binding and AF-2 domains. Mammalian expression vectors encoding ER alpha, delta 5ER alpha, and/or ER beta complementary DNAs were transiently transfected along with an E2 response element promoter-luciferase (ERELuc) reporter into human ER alpha/ER beta-negative osteosarcoma U2-OS cells. ER beta was less potent than ER alpha in activating E2-stimulated ERELuc activity (4-vs. 14-fold relative to basal control levels). However, when delta 5ER alpha was coexpressed with ER beta or ER alpha, E2-stimulated ERELuc activity was markedly increased to 8- and 57-fold, respectively, relative to basal control levels when each full-length isoform was expressed alone. Finally, coexpression of ER beta with ER alpha did not significantly alter the E2-stimulated ERELuc activity induced by ER alpha alone. Cotreatment with tamoxifen markedly inhibited all E2-stimulated ERELuc responses to baseline levels. Together, these data suggest that ER beta has a minor role in mediating E2 responses in ER alpha-positive tumors, but may be the main mediator of E2-stimulated gene expression when expressed alone in somatotroph, corticotroph, and null cell tumors. This low, but significant, level of ER beta trans-activation potential may be enhanced by coexpression of delta 5ER alpha in neoplastic pituitary. Therefore, E2-mediated gene expression in normal and neoplastic pituitary appears to be highly dependent on the expression of ER alpha and ER beta isoforms, which have varying transcriptional activities.

Biochemical assessment of Cushing's disease in patients with corticotroph macroadenomas.

The majority of cases of Cushing's disease are due to an underlying pituitary corticotroph microadenoma (< or = 10 mm). Corticotroph macroadenomas (> 10 mm) are a less common cause of Cushing's disease, and little is known about specific clinical and biochemical findings in such patients. To define further the clinical characteristics of patients with corticotroph macroadenomas, we performed a retrospective review of Cushing's disease due to macroadenomas seen at Massachusetts General Hospital between 1979 and 1995. Of 531 patients identified with a diagnostic code of Cushing's syndrome, 20 were determined to have Cushing's disease due to a macroadenoma based on radiographic evidence of pituitary adenoma greater than 10 mm and pathological confirmation of a pituitary adenoma. A comparison review of charts of 24 patients with Cushing's disease due to corticotroph microadenomas identified on the basis of radiographic evidence of a normal pituitary gland or a pituitary adenoma 10 mm or less in diameter was also performed. The mean ages of the patients (+/- SD) with macroadenomas and microadenomas were similar (39 +/- 12 and 38 +/- 14 yr, respectively). The baseline median 24-h urine free cortisol (UFC) excretion was 1341 nmol/day (range, 304-69,033 nmol/day) and 877 nmol/day (range, 293-2,558 nmol/day) for macroadenoma and microadenoma patients, respectively (P = 0.058). After the 48-h high dose dexamethasone suppression test, UFC decreased by 77 +/- 19% (mean +/- SD) and 91 +/- 7% in macroadenoma and microadenoma subjects, respectively (P = 0.04). Fifty-six percent of macroadenoma patients and 92% of microadenoma patients had greater than 80% suppression of UFC after high dose dexamethasone administration (P = 0.03). The baseline median 24-h urinary 17-hydroxysteroid (17-OHCS) excretion was 52 mumol/day (range, 25-786 mumol/day) and 44 mumol/day (range, 17-86 mumol/day) for macroadenoma and microadenoma subjects, respectively (P = 0.09). After the standard high dose dexamethasone suppression test, 17-OHCS excretion decreased by 46 +/- 33% and 72 +/- 22% for macroadenoma and microadenoma subjects, respectively (P = 0.02). Fifty-three percent of patients with macroadenomas and 86% of patients with microadenomas had greater than 50% suppression of 17-OHCS after high dose dexamethasone administration (P = 0.02). Baseline plasma ACTH values were above the normal range in 83.3% of macroadenoma patients and in 45% of microadenoma subjects (P = 0.05). Tumors were immunostained with the MIB-1 antibody for Ki-67 to investigate proliferation in the adenomas. There was a trend for a higher Ki-67 labeling index in corticotroph macroadenomas, and seven (44%) macroadenomas vs. three (18%) microadenomas had labeling indexes greater than 3%, but this was not statistically significant. In summary, corticotroph macroadenomas are often associated with less glucocorticoid suppressibility than the more frequently occurring microadenomas. Therefore, the lack of suppression of UFC or 17-OHCS after the administration of high dose dexamethasone in a patient with Cushing's disease does not necessarily imply the presence of ACTH-independent Cushing's syndrome and is more commonly seen in patients with corticotroph macroadenomas than in those with microadenomas. Increased plasma ACTH concentrations are typical of patients with corticotroph macroadenomas and may be a more sensitive indicator of neoplastic corticotrophs than the UFC or 17-OHCS response to standard high dose dexamethasone testing.

Transfacial transclival approach for midline posterior circulation aneurysms.

OBJECTIVE: To evaluate the use of an anterior, transfacial transclival approach to midline posterior circulation aneurysms in five patients. SURGICAL APPROACH: A skin incision is made on the right side of the nose with subsequent bony and cartilaginous disarticulation of the nasal complex. The nose remains attached along the left side and is reflected laterally. Removal of the nasal septum and bilateral ethmoidectomy, medial maxillectomy (usually bilateral), and opening of the sphenoid yield a large triangular exposure of the anterior clivus. After removal of the clivus with a drill, the vertebral and basilar arteries are exposed through a midline dural opening. RESULTS: The approach provided excellent exposure of basilar artery trunk aneurysms with room available for temporary clip placement in three patients. In a fourth patient, a midline posterior inferior cerebellar artery aneurysm was clipped using this technique. A basilar trunk dissection was treated by proximal basilar occlusion through this exposure in a fifth patient. Although three patients developed transient cerebrospinal fluid leaks with symptoms of meningitis, no permanent neurological morbidity resulted from the use of the approach. CONCLUSION: The transfacial transclival approach to midline aneurysms of the basilar trunk and its branches provided excellent exposure for surgical treatment in five patients. No patient had postoperative palatal dysfunction and cosmetic results were excellent. Cerebrospinal fluid leak and meningitis continue to be the major drawbacks to the use of this approach, although the availability of modern broad-spectrum antibiotics lessens the chance of permanent neurological sequelae.

Anterior midline approaches to the central skull base.

Anterior midline approaches are safe and appropriate for extradural lesions of the central brain base. They are occasionally warranted for intradural lesions as well. Transnasal routes expose the clivus well. They are readily expanded superiorly, inferiorly, and laterally. Recent innovations are reductive; they expand exposure with less facial disassembly. Lateral and most intradural extensions of lesions warrant more lateral approaches.

Serum insulin-like growth factor-binding protein-3 levels in the diagnosis of acromegaly.

Insulin-like growth factor-binding protein-3 (IGFBP-3) is a GH-dependent protein that binds insulin-like growth factor-I (IGF-I) in the circulation and modulates its action at the tissue level. Because IGFBP-3 is a stable and specific marker of somatotroph function, we hypothesized that it would be a useful biochemical marker in the diagnosis of patients with acromegaly and the assessment of surgical cure. We, therefore, investigated the sensitivity of serum IGFBP-3 levels to detect GH excess in 44 patients with clinical acromegaly and pathologically confirmed somatotroph adenomas, including a cohort of 18 patients with untreated disease evaluated before transsphenoidal surgery and medical therapy. IGFBP-3 levels were compared to IGF-I and random GH levels before and after transsphenoidal surgery. Concordance among IGFBP-3, IGF-I, and GH suppressibility by glucose was also determined. In addition, the response of IGFBP-3 to glucose suppression was investigated. All 18 patients with untreated acromegaly had elevated serum IGFBP-3 levels, ranging from 4,186-10,026 micrograms/L (mean +/- SD, 6566 [plusm] 1800 micrograms/L). There was no overlap with the age-adjusted normative ranges (P = 0.0001 in patients 18-55 yr old and P = 0.0176 in patients > 55 yr old) or with the levels obtained in age-comparable controls (P = 0.0001). In 11% of untreated patients with clinical findings of acromegaly and a pathologically confirmed adenoma, IG-FBP-3 levels were elevated, although GH was suppressed to less than 2 micrograms/L with glucose. In these patients, IGF-I levels were either normal or minimally elevated and considered nondiagnostic. IGFBP-3 and IGF-I levels were correlated in patients with untreated acromegaly (r = 0.650; P = 0.0162) and after transsphenoidal surgery (r = 0.644; P = 0.0001). Neither IGF-I nor IGFBP-3 correlated with random GH levels before surgery. However, both IGF-I (r = 0.471; P = 0.0001) and IGFBP-3 (r = 0.259; P = 0.041) correlated with random GH levels in patients studied more than 1 month after transsphenoidal surgery. IGFBP-3 and IGF-I levels were concordant with GH suppressibility by glucose (P = 0.0039) and IGFBP-3 decreased with glucose suppression in 7 of 10 patients. These data indicate that IGFBP-3 is a sensitive physiological marker of somatotroph function and is concordant with glucose suppression and IGF-I levels before and after transsphenoidal surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Human pituitary adenomas express endogenous inhibin subunit and follistatin messenger ribonucleic acids.

Specific factors involved in the pathogenesis of tumors that stimulate clonal human pituitary adenoma cell proliferation remain unknown. An important question regarding the pathogenesis of human pituitary tumors is whether they synthesize autocrine regulatory factors that regulate both hormone biosynthesis and neoplastic growth. Activin and inhibin are both comprised of inhibin subunits and have diverse regulatory roles as growth and differentiation factors in normal and neoplastic tissue. Activin stimulates FSH beta messenger ribonucleic acid (mRNA) biosynthesis and FSH secretion, and these effects are down-regulated in normal gonadotrophs by the endogenous glycoprotein follistatin. In addition to its effects on gonadotrophs, activin modulates hormone secretion by somatotroph and corticotroph cell lines. It is not known whether human neoplastic pituitary tissue synthesizes inhibin subunits or follistatin or whether their expression is cell type specific. We investigated whether alpha-, beta A-, and beta B-inhibin subunit and follistatin mRNAs could be detected in 27 human pituitary adenomas [clinically nonfunctioning (n = 11), somatotroph (n = 5), corticotroph (n = 5), and lactotroph (n = 6)] using reverse transcriptase-polymerase chain reaction techniques. Twenty-six of the tumors contained mRNAs encoding one or more inhibin subunits. beta B-Inhibin mRNA was the most prevalent (81% of tumors), followed by beta A-inhibin (59% of tumors) and alpha-inhibin (52% of tumors). Endogenous alpha-, beta A-, and beta B-inhibin subunit mRNA synthesis was also examined in normal human pituitary and testicular complementary DNA libraries, and all subunit mRNAs were detected. In contrast to the widespread expression of inhibin subunits in pituitary tumors, follistatin mRNA was detected in a subset of nonfunctioning tumors (54%) as well as in control normal human pituitary and testicular complementary DNA libraries. Tumor-specific follistatin biosynthesis was not observed in other pituitary tumor subtypes. These data are the first to demonstrate that 1) endogenous inhibin subunits are synthesized in human pituitary adenomas of all known secretory phenotypes as well as normal pituitary tissue; and 2) follistatin gene expression in pituitary adenomas is specific to clinically nonfunctioning or gonadotropin subunit-producing tumors. The characterization of inhibin subunit and follistatin biosynthesis by human pituitary tumors will be important in investigating their potential roles in regulating both tumor phenotype and cell proliferation.