Corticotroph tumor progression speed after adrenalectomy

OBJECTIVES

After bilateral adrenalectomy in Cushing's disease, corticotroph tumor progression occurs in one-third to half of patients. However, progression speed is variable, ranging from slow to rapid. The aim was to explore corticotroph progression speed, its consequences and its risk factors.

DESIGN

A retrospective single-center observational study.

METHODS

In total,103 patients with Cushing's disease who underwent bilateral adrenalectomy between 1990 and 2020 were included. Clinical, biological, histological and MRI features were collected. Median duration of follow-up after bilateral adrenalectomy was 9.31 years.

RESULTS

In total,44 patients progressed (43%). Corticotroph tumor progression speed ranged from 1 to 40.7 mm per year. Progression speed was not different before and after bilateral adrenalectomy (P = 0.29). In univariate analyses, predictive factors for rapid corticotroph tumor progression included the severity of Cushing's disease before adrenalectomy as the cause of adrenalectomy, high ACTH in the year following adrenalectomy and high Ki67 immunopositivity in the tumor. During follow-up, early morning ACTH absolute variation was associated with corticotroph tumor progression speed (P-value = 0.001). ACTH measurement after dynamic testing did not improve this association.

CONCLUSION

After adrenalectomy, corticotroph progression speed is highly variable and manageable with MRI and ACTH surveillance. Progression speed does not seem related to bilateral adrenalectomy but rather to intrinsic properties of highly proliferative and secreting tumors.

Cushing's disease: role of bilateral adrenalectomy

INTRODUCTION

Laparoscopic bilateral adrenalectomy (BAD) is one of the treatments of Cushing's Disease (CD), but its indications and outcome is debated.

METHODS

The literature on BAD was reviewed as part of a work performed for the Cushing's disease guideline.

RESULTS

The surgical morbidity of BAD is reported between 10 and 18% and no mortality has been reported in the largest series. Because of the endocrine sacrifice it will be mostly performed after a multidisciplinary team discussion in selected cases of refractory CD (mostly after failure of pituitary surgery and/or medical treatment). It is also frequently discussed in female patients desiring pregnancy. Corticotroph tumor progression occurs in 40% of the patients but is in most patients manageable when detected early by a careful long term monitoring with pituitary MRI and ACTH assays after BAD.

CONCLUSION

BAD is a safe and effective treatment of CD used in specific situations and requiring long term monitoring.

Role of Radiation in the treatment of Cushing Disease

In Cushing disease (CD), radiation therapy (RT) is mostly used in the adjuvant setting in patients who have failed transsphenoidal surgery or have recurrent CD. Stereotactic radiotherapy (SRT) is administered as either single or several sessions, and the most commonly used modalities include photon source (Gamma Knife, CyberKnife, and LINAC) or heavy particles (protons). In multicenter studies, Gamma Knife SRT can lead to biochemical control in 80%, with medial time to remission approximately 15 mos, and 70% recurrence free at 10 years. Conventional RT (CRT) consists of administration of small daily fractions over six weeks, with cumulative dose of 45-50 Gy. Biochemical control is achieved in up to 64% of patients with CRT. Choice of radiation modality includes convenience for patients (SRT is more convenient) and proximity to critical structures. Both forms of RT can result in hypopituitarism. RT remains an important modality for the treatment of patients with CD.

Paediatric Cushing's disease: Epidemiology, pathogenesis, clinical management and outcome

Cushing's disease (CD) is rare in paediatric practice but requires prompt investigation, diagnosis and therapy to prevent long-term complications. Key presenting features are a change in facial appearance, weight gain, growth failure, virilization, disturbed puberty and psychological disturbance. Close consultation with an adult endocrinology department is recommended regarding diagnosis and therapy. The incidence of CD, a form of ACTH-dependent Cushing's syndrome (CS), is equal to approximately 5% of that seen in adults. The majority of ACTH-secreting adenomas are monoclonal and sporadic, although recent studies of pituitary tumours have shown links to several deubiquitination gene defects. Diagnosis requires confirmation of hypercortisolism followed by demonstration of ACTH-dependence. Identification of the corticotroph adenoma by pituitary MRI and/or bilateral inferior petrosal sampling for ACTH may contribute to localisation before pituitary surgery. Transsphenoidal surgery (TSS) with selective microadenomectomy is first-line therapy, followed by external pituitary irradiation if surgery is not curative. Medical therapy to suppress adrenal steroid synthesis is effective in the short-term and bilateral adrenalectomy should be considered in cases unfit for TSS or radiotherapy or when urgent remission is needed after unsuccessful surgery. TSS induces remission of hypercortisolism and improvement of symptoms in 70-100% of cases, particularly when performed by a surgeon with experience in children. Post-TSS complications include pituitary hormone deficiencies, sub-optimal catch-up growth, and persisting excess of BMI. Recurrence of hypercortisolism following remission is recognised but infrequent, being less common than in adult CD patients. With experienced specialist medical and surgical care, the overall prognosis is good. Early referral to an experienced endocrine centre is advised.

Apoplexy of Crooke cell tumour leading to the diagnosis of severe Cushing disease; a case report

BACKGROUND

Patients with Crooke cell tumours present with features of Cushing syndrome or mass effect. There are few reports of patients with Crooke cell tumours presenting due to apoplexy. All of them had silent tumours. Patients with Cushing syndrome caused by Crooke cell tumours have not been reported to present with apoplexy.

CASE PRESENTATION

A 35-year-old female presented with sudden onset headache and visual loss for 1 week. She had secondary amenorrhoea for 10 years. There were features of Cushing syndrome including central obesity, multiple monomorphic acne, dorso-cervical and supraclavicular fat pads, hypertension, proximal weakness, pigmentation and refractory hypokalaemia. She was found to have markedly elevated serum cortisol, central hypothyroidism and hypogonadotropic hypogonadism. There was a mass in the sellar region (4.7 cm × 1.9 cm × 5.3 cm) suggestive of a pituitary tumour extending to the suprasellar region. Imaging showed evidence of bleeding and compression of the optic chiasm. She underwent urgent trans-sphenoidal excision of the tumour. Histology was compatible with a pituitary neuroendocrine tumour. There was margination of ACTH reactivity to the cell periphery and ring like positivity in most of the cells in the cytokeratin stain. Features were in favour of a Crooke cell tumour. After surgery she improved gradually and became eucortisolaemic.

CONCLUSIONS

This is a unique presentation of an apoplexy of Crooke cell tumour causing Cushing syndrome. Delayed health seeking behaviour of this patient despite severe Cushing disease could have led to this presentation which has not been reported before.

A human ACTH-secreting corticotroph tumoroid model: Novel Human ACTH-Secreting Tumor Cell in vitro Model

BACKGROUND

Cushing disease (CD), although rare, is a life-threatening disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma, which leads to excess adrenal-derived cortisol. Efficacious and safe medical therapies that control both hormonal hypersecretion and pituitary corticotroph tumor growth remain an unmet need in the management of CD. Translational research in pituitary tumors has been significantly hampered by limited quantities of surgically resected tissue for ex vivo studies, and unavailability of human pituitary tumor cell models.

METHODS

To characterize human corticotroph tumors at the cellular level, we employed single cell RNA-sequencing (scRNA-seq) to study 4 surgically resected tumors. We also used microarrays to compare individualized paired consecutive culture passages to understand transcriptional shifts as in vitro cultures lost ACTH secretion. Based on these findings, we then modified our in vitro culture methods to develop sustained ACTH-secreting human corticotroph tumoroid cultures.

FINDINGS

scRNA-seq identified 4 major cell populations, namely corticotroph tumor (73.6%), stromal (11.2%), progenitor (8.3%), and immune cells (6.8%). Microarray analysis revealed striking changes in extracellular matrix, cell adhesion and motility-related genes concordant with loss of ACTH secretion during conventional 2D culture. Based on these findings, we subsequently defined a series of crucial culture nutrients and scaffold modifications that provided a more favorable trophic and structural environment that could maintain ACTH secretion in in vitro human corticotroph tumor cultures for up to 4 months.

INTERPRETATION

Our human corticotroph tumoroid model is a significant advance in the field of pituitary tumors and will further enable translational research studies to identify critically needed therapies for CD.

FUNDING

This work was partly funded by NCI P50-CA211015 and the Warley Trust Foundation.

Postoperative Day 1 Morning Cortisol Value as a Biomarker to Predict Long-term Remission of Cushing Disease

CONTEXT

Recurrence of Cushing disease (CD) can occur even decades after surgery. Biomarkers to predict recurrence of CD after surgery have been studied but are inconclusive.

OBJECTIVE

The aim of our study was to identify specific biomarkers that can predict long-term remission after neurosurgery.

DESIGN

Identification of specific biomarkers to predict long-term remission of CD was performed by logistic regression analysis followed by Kaplan-Meier survival analysis, using recurrence as the dependent variable.

SETTING

A total of 260 patients with CD identified from our institutional research patient data registry search tool and from patients who presented to our longitudinal multidisciplinary clinic between May 2008 and May 2018 underwent statistical analysis.

INTERVENTIONS

Data on clinical features, neuro-imaging study, pathology, biochemistry, and treatments were collected by reviewing digital chart records.

MAIN OUTCOME MEASURE

Postoperative cortisol as a biomarker to predict long-term remission after surgical treatment for CD.

RESULTS

By logistic regression analysis, postoperative day 1 (POD1) morning (5-10 am) serum cortisol, female sex, and proliferative index had significant association with CD recurrence (odds ratio [OR] = 1.025, 95% CI: 1.002-1.048, P = .032). In contrast, the postoperative nadir cortisol (OR = 1.081, 95% CI: 0.989-1.181, P = .086), urinary free cortisol (OR = 1.032, 95% CI: 0.994-1.07, P = .098), and late night salivary cortisol (OR = 1.383, 95% CI: 0.841-2.274, P = .201) had no significant correlation with recurrence. A significant association between POD1 morning serum cortisol and long-term CD remission was verified by Kaplan-Meier analysis when using POD1 morning serum cortisol <5 μg/dL as the cut-off.

CONCLUSIONS

The POD1 morning serum cortisol level has a significant association with CD recurrence.

Diabetes, Active Disease, and Afternoon Serum Cortisol Levels Predict Cushing's Disease Mortality: A Cohort Study

CONTEXT

Cushing's disease (CD) is a life-threating disease, with increased mortality in comparison with the general population.

OBJECTIVE

This study aimed to evaluate standardized mortality ratios (SMRs) in CD patients. We also analyzed independent risk factors related to increased mortality.

DESIGN

We conducted a longitudinal cohort study in a 3rd level specialty center, from 1979 to 2018, in patients with CD.

RESULTS

From 1375 cases with a pathology diagnosis of pituitary adenoma, 191 cases had the confirmed diagnosis of CD (14%). A total of 172 patients completed follow-up, with a mean age at diagnosis of 33 ± 11 years, female predominance (n = 154, 89.5%), majority of them with microadenoma (n = 136, 79%), and a median follow-up of 7.5 years (2.4-15). Eighteen patients (10.5%) died, 8 of them (44%) were with active CD, 8 (44%) were under remission, and 2 (11%) were under disease control. Estimated all-cause SMR = 3.1, 95% confidence interval (CI) 1.9-4.8, P < 0.001. Cardiovascular disease was the main cause of death (SMR = 4.2, 1.5-9.3, P = 0.01). Multivariate Cox regression models adjusted for potential cofounders showed that diabetes (HR = 5.2, IC 95% 1.8-15.4, P = 0.002), high cortisol levels after 1600 hours at diagnosis (3.4, 2.3-7.0, P = 0.02), and active CD (7.5, 3.8-17.3, P = 0.003) significantly increased the risk of mortality.

CONCLUSIONS

Main cause of CD mortality was cardiovascular disease. Main risk factors for mortality were uncontrolled diabetes, persistently high cortisol levels after 1600 hours at diagnosis, and active disease at last follow-up.

Results and predictors of outcome of endoscopic endonasal surgery in Cushing's disease: 20-year experience of an Italian referral Pituitary Center

PURPOSE

To assess outcomes and predictors of early and long-term remission in patients with Cushing's disease (CD) due to ACTH-secreting adenomas treated via endoscopic endonasal approach (EEA).

METHODS

This is a retrospective study. Consecutive patients operated for CD from 1998 to 2017 in an Italian referral Pituitary Center were enrolled. Clinical, radiological, and histological data at enrollment and follow-up were collected.

RESULTS

151 patients (107 F) were included; 88.7% were naïve for treatment, 11.3% had been treated surgically and 11.2% medically. At pre-operative magnetic resonance imaging (MRI), 35 had a macroadenoma and 80 a microadenoma, while tumor was undetectable in 36 patients. Mean age at surgery was 41.1 ± 16.6 years. Diagnosis was confirmed histologically in 82.4% of the cases. Patients with disease persistence underwent second surgery and/or medical and/or radiation therapy. Mean follow-up was 92.3 ± 12.0 (range 12-237.4) and median 88.2 months. Remission rate was 88.1% after the first surgery and 90.7% at last follow-up. One patient died of pituitary carcinoma. Post-surgical cortisol drop (p = 0.004), tumor detection at MRI (p = 0.03) and size < 1 cm (p = 0.045) increased the chance of disease remission; cavernous sinus invasion was a negative predictor of outcome (p = 0.002). Twenty-seven patients developed diabetes insipidus and 18 hypopituitarism. Surgery repetition increased the risk of hypopituitarism (p = 0.03), but not of other complications, which included epistaxis (N = 2), cerebrospinal fluid leakage (1), pneumonia (3), myocardial infarction (1), and pulmonary embolisms (2).

CONCLUSIONS

Selective adenomectomy via EEA performed by experienced surgeons, supported by a multidisciplinary dedicated team, allows long-term remission in the vast majority of CD patients with low complication rate.

Advances in the Medical Treatment of Cushing Disease

Medical therapy has an adjunctive role in management of Cushing disease. Medical therapy is recommended for patients who received pituitary radiotherapy and are awaiting its salutary effects. Medications are used preoperatively to stabilize the condition of seriously ill patients before surgery. Medical therapy is used to control hypercortisolism in patients with uncertain tumor location. Medical therapies available for management of patients with Cushing disease include steroidogenesis inhibitors, centrally acting agents, and glucocorticoid receptor antagonists. All agents require careful monitoring to optimize clinical effectiveness and manage adverse effects. Novel agents in development may expand the armamentarium for management of this condition.

The Role of Dopamine Agonists in Pituitary Adenomas

Dopamine agonist therapy is the primary therapy for prolactin-secreting adenomas and usually results in normoprolactinemia, eugonadism, and tumor reduction. Cabergoline is superior to bromocriptine with regard to efficacy and tolerance. Withdrawal of cabergoline can be attempted in patients with normal prolactin levels on low doses of medication and evidence of radiographic tumor involution. Dopamine agonists have been used off label in patients with acromegaly, Cushing disease, and nonfunctioning adenomas. A trial of cabergoline monotherapy can be effective in patients with biochemically mild acromegaly. Cabergoline combination with somatostatin receptor ligands or pegvisomant improves insulin-like growth factor level 1 in majority of patients.

Nelson's Syndrome: An Update

Nelson's syndrome (NS) is a condition which may develop in patients with Cushing's disease after bilateral adrenalectomy. Although there is no formal consensus on what defines NS, corticotroph tumor growth and/or gradually increasing ACTH levels are important diagnostic elements. Pathogenesis is unclear and well-established predictive factors are lacking; high ACTH during the first year after bilateral adrenalectomy is the most consistently reported predictive parameter. Management is individualized and includes surgery, with or without radiotherapy, radiotherapy alone, and observation; medical treatments have shown inconsistent results. A subset of tumors demonstrates aggressive behavior with challenging management, malignant transformation and poor prognosis.

Use of late-night salivary cortisol to monitor response to medical treatment in Cushing's disease

OBJECTIVE

Monitoring of patients with Cushing's disease on cortisol-lowering drugs is usually performed with urinary free cortisol (UFC). Late-night salivary cortisol (LNSC) has an established role in screening for hypercortisolism and can help to detect the loss of cortisol circadian rhythm. Less evidence exists regarding the usefulness of LNSC in monitoring pharmacological response in Cushing's disease.

DESIGN

Exploratory analysis evaluating LNSC during a Phase III study of long-acting pasireotide in Cushing's disease (clinicaltrials.gov: NCT01374906).

METHODS

Mean LNSC (mLNSC) was calculated from two samples, collected on the same days as the first two of three 24-h urine samples (used to calculate mean UFC [mUFC]). Clinical signs of hypercortisolism were evaluated over time.

RESULTS

At baseline, 137 patients had evaluable mLNSC measurements; 91.2% had mLNSC exceeding the upper limit of normal (ULN; 3.2 nmol/L). Of patients with evaluable assessments at month 12 (n = 92), 17.4% had both mLNSC ≤ULN and mUFC ≤ULN; 22.8% had mLNSC ≤ULN, and 45.7% had mUFC ≤ULN. There was high variability in LNSC (intra-patient coefficient of variation (CV): 49.4%) and UFC (intra-patient CV: 39.2%). mLNSC levels decreased over 12 months of treatment and paralleled changes in mUFC. Moderate correlation was seen between mLNSC and mUFC (Spearman's correlation: ρ = 0.50 [all time points pooled]). Greater improvements in systolic/diastolic blood pressure and weight were seen in patients with both mLNSC ≤ULN and mUFC ≤ULN.

CONCLUSION

mUFC and mLNSC are complementary measurements for monitoring treatment response in Cushing's disease, with better clinical outcomes seen for patients in whom both mUFC and mLNSC are controlled.

A rare case of pituicytoma presenting with severe Cushing disease: A case report and review of literature

RATIONALE

Pituicytomas are exceptional rare tumors in the sellar and suprasellar regions with clinical manifestations, such as headache, visual disturbance, hypopituitarism, and decreased libido. Unlike that of common pituitary adenoma, the association between pituicytoma and Cushing disease (CD) is extremely rare. There were only 6 reported cases till now. In the current study, we describe an unusual case of pituicytoma associated with severe CD with a recurrence-free follow-up period of 49 months.

PATIENT CONCERNS

A 32-year-old woman was referred to our hospital with moon face, central obesity, and purple stripes on the lower limbs.

DIAGNOSES

The plasma cortisol level was 1122 nmol/L. The low-dose dexamethasone suppression test failed to suppress plasma cortisol. This test provided evidence of nonpituitary-dependent CD. However, magnetic resonance imaging demonstrated a sellar mass measuring approximately 7.6 × 5.7 mm. The patient was diagnosed with pituitary microadenoma. Histopathological analysis of the tissue sections based on the findings from the immunohistochemical staining diagnosed it as pituicytoma.

INTERVENTIONS

Transsphenoidal surgery was performed to remove the pituitary mass.

OUTCOMES

Within 2 months postoperatively, the patient's blood pressure and cortisol level decreased gradually and normalized on the 6th month when other symptoms of CD also disappeared. The patient is presently free from recurrence 49 months after the initial diagnosis.

LESSONS

Based on the postoperative remission, CD was caused by pituitary disorders. A reasonable assumption is that an extremely small coexisting adenoma was not detected by the surgeon and washed out during the dissection. Another possible explanation might be the mass effect caused by this intrasellar lesion.

The Utility of Intraoperative Cytological Smear and Frozen Section in the Surgical Management of Patients with Cushing's Disease due to Pituitary Microadenomas

Cushing's disease (CD) is most commonly caused by a microadenoma, which at surgical exploration may not provide adequate tissue for pathologic diagnosis using standard techniques. We wished to determine the accuracy of intraoperative pathologic examination and whether the addition of intraoperative cytology increased the diagnostic yield. We reviewed the pathology reports from 403 operations on 341 patients with CD microadenomas from a single institution. The concordance rates of intraoperative diagnoses (cytology and frozen) with the final (paraffin section) pathological diagnosis were calculated. The overall pathologic confirmation of an adenoma (by either cytology, frozen, or paraffin section) was compared with the result from a historical cohort (using only standard frozen section analysis but not intraoperative cytology) and the pooled result from a meta-analysis of previously published data. The concordance rate between frozen section diagnosis and paraffin section histology was 390/403 (96.8%). The concordance rate between cytological smear and paraffin section histology was 213/246 (86.6%). In 54 cases (13.4%) with ultimate remission, pathologic confirmation was obtained only on intraoperative pathology (frozen section or cytology). Overall, pathologic confirmation was obtained in 326 operations (80.9%) by at least one pathological modality. The overall pathological confirmation of an adenoma was greater after the introduction of intraoperative cytology when compared with the historical control (67.1%, p = 0.015), and compared with the pooled rate of published data from the meta-analysis (72.1%, p < 0.001). Our findings suggest that addition of intraoperative cytological analyses during surgery for CD is an additional useful diagnostic tool for both neurosurgeons and pathologists.

Successful reduction of ACTH secretion in a case of intractable Cushing's disease with pituitary Crooke's cell adenoma by combined modality therapy including temozolomide

Crooke's cell adenoma (CCA) is an aggressive subtype of corticotroph adenoma; however, CCA is associated with a high incidence of low expression of methyl guanine methyl transferase (MGMT), suggesting that temozolomide (TMZ) treatment might be effective for this tumor type. The case of a 56-year-old woman with Cushing's disease caused by a pituitary CCA is presented. At the age of 38 years, the patient presented to our hospital with polyuria and a visual field defect. MRI and laboratory studies showed a 4.5-cm-diameter pituitary tumor with plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels of more than 500 pg/mL and 40 μg/dL, respectively. At 39 years of age, the patient underwent a craniotomy, and her plasma ACTH and cortisol levels decreased to less than 200 pg/mL and 10 μg/dL, respectively; however, these hormone levels increased gradually to 3,940 pg/mL and 70 μg/dL, respectively, by the time the patient was 56 years old. Histopathological re-examination of the previously resected specimen showed that the pituitary tumor was MGMT-negative CCA. TMZ treatment after the second operation decreased the plasma ACTH levels from 600-800 pg/mL to 70-300 pg/mL. No signs of recurrence were observed in the seven years following these treatments with added prophylactic radiation therapy. These clinical findings suggest that TMZ treatment to patients with CCA accompanied with elevated ACTH may be good indication to induce lowering ACTH levels and tumor shrinkage.

Cushing's disease due to somatic USP8 mutations: a systematic review and meta-analysis

PURPOSE

Cushing's disease (CD) is a severe illness generally caused by microcorticotropinomas (MICs) and in approximately 7-20% of patients by macrocorticotropinomas (MACs). USP8-mutations have been identified as a major genetic cause of CD (~ 50%). Few studies have reported the distribution between MICs-MACs related to USP8-mutations and their genotype-phenotype correlations. Therefore, we aimed to evaluate USP8-mutations in a cohort of MICs-MACs from a unique center and to perform a systematic review and meta-analysis.

METHODS

DNA-tumor-tissues from 47 corticotropinomas (16 MICs and 31 MACs) were sequenced. Clinical-biochemical data, radiological imaging data and remission/recurrence rates were evaluated. In addition, we performed a meta-analysis of nine published series (n = 630).

RESULTS

We identified four different USP8-mutations previously described, in 11 out of 47 (23.4%) corticotropinomas; 8 out of 11 were MACs. The urinary cortisol levels of our patients with corticotrophin USP8-mutated-alleles were lower than those of patients with wild-type (WT) alleles (p ≤ 0.017). The frequency of USP8-mutated-alleles among the series was approximately 30% with a higher prevalence in female-patients (p < 0.1 × 10^-4). Among the 5 series, the remission rates were higher in patients with USP8-mutated-alleles than in those with the USP8-WT-alleles (p < 0.1 × 10^-4).

CONCLUSION

Our data, as well as the retrospective review of CD series associated with USP8-mutated alleles, show heterogeneous findings among the series. Several drawbacks included the lack of a systematic protocol to evaluate these patients before surgery and follow-up. Further prospective studies using a systematic protocol will provide more consistent information about the influence of the corticotropinomas with USP8-mutated alleles on the phenotype, responses to treatment and outcome of patients with CD.

An Institutional Experience of Tumor Progression to Pituitary Carcinoma in a 15-Year Cohort of 1055 Consecutive Pituitary Neuroendocrine Tumors

Pituitary carcinoma is a rare disease, defined by the presence of cerebrospinal or distant metastasis of a pituitary neuroendocrine tumor (PitNET). To review our institutional experience of pituitary carcinoma, we searched the database of the UHN Endocrine Oncology Site group and the University Health Network pathology laboratory information system from 2001 to 2016. Among 1055 PitNETs from 1169 transsphenoidal resections, we identified 4 cases of pituitary carcinoma, indicating that pituitary carcinoma represents around 0.4% of PitNETs. All four patients were women. The age at initial presentation ranged from 23 to 54 years. Two patients had Cushing disease with corticotroph tumors; one was initially a densely granulated corticotroph tumor that evolved to become sparsely granulated, while the other was a Crooke cell tumor. One patient had a functioning sparsely granulated lactotroph tumor and one had a clinically silent poorly differentiated PIT1 lineage tumor. Apart from a relatively high Ki67 labeling index (≥ 10%) in three tumors, there were no cytomorphologic features at the time of initial presentation that could predict subsequent metastatic behavior. The time from diagnosis of the pituitary neuroendocrine tumor to the diagnosis of malignancy was 3 to 14 years. Therapies included somatostatin analogs, external beam radiotherapy, chemotherapies including capecitabine/temozolomide, everolimus, sunitinib, bevacizumab, and peptide receptor radionuclide therapy (PRRT). One patient died of disease 18 years after initial diagnosis, underscoring the protracted course of this ultimately fatal neuroendocrine malignancy.

Outcomes of three-Tesla magnetic resonance imaging for the identification of pituitary adenoma in patients with Cushing's disease

Pituitary adenoma has been reported to be detectable in only 36-63% of Cushing's disease (CD) patients by magnetic resonance imaging (MRI). In this study, we investigate the outcomes and problems associated with tumor identification using 3-Tesla (3-T) MRI, which provides clearer images than ≤1.5-T MRI, in 115 patients who were initially diagnosed with CD. Before surgery, 31 macroadenomas (27%) and 54 microadenomas (47%) were identified by 3-T MRI, but pituitary adenoma was invisible on MRI in the remaining 30 cases (26%). The smallest tumor diameter amenable to a definitive diagnosis was 2 mm, and spoiled gradient-echo was the best sequence for diagnosing microadenomas. In 14 of 30 cases of MRI-invisible CD, the pituitary adenoma was identified during surgery. Nine of these 14 tumors that developed from outside the pituitary gland were retrospectively identified on MRI by comparison with surgical findings. The remaining 16 cases of MRI-invisible CD in which the pituitary adenoma was not identified during surgery involved partial hypophysectomy. Seven cases were hormonally remitted, but another nine cases experienced persistent disease after surgery. The sensitivity and specificity of the pituitary adenoma diagnosis in CD patients after the introduction of 3-T MRI were 80% and 100%, respectively. However, the sensitivity decreased to 72% when macroadenomas were excluded. Some adenomas associated with CD are still undetectable on 3-T MRI due to tumor size, location and intensity. However, sensitivity can be improved by monitoring tumors that develop outside the pituitary gland.

Tumor-Directed Therapeutic Targets in Cushing Disease

CONTEXT

The most frequent cause of endogenous hypercortisolism is Cushing disease (CD), a devastating condition associated with severe comorbidities and high mortality. Effective tumor-targeting therapeutics are limited.

DESIGN

Search in PubMed with key words "corticotroph" and "Cushing's disease" plus the name of the mentioned therapeutic agent and in associated references of the obtained papers. Additionally, potential therapeutics were obtained from ClinicalTrials.gov with a search for "Cushing disease."

RESULTS

At present, the tumor-targeted pharmacological therapy of CD is concentrated on dopamine agonists (cabergoline) and somatostatin analogs (pasireotide) with varying efficacy, escape from response, and considerable side effects. Preclinical studies on corticotroph pathophysiology have brought forward potential drugs such as retinoic acid, silibinin, and roscovitine, whose efficacy and safety remain to be determined.

CONCLUSIONS

For many patients with CD, effective tumor-targeted pharmacological therapy is still lacking. Coordinated efforts are pivotal in establishing efficacy and safety of novel therapeutics in this rare but devastating disease.

Ca2+ Channels in Anterior Pituitary Somatotrophs: A Therapeutic Perspective

Ca2+ influx through voltage-gated Ca2+ channels (VGCCs) plays a key role in GH secretion. In this review, we summarize the current state of knowledge regarding the physiology and molecular machinery of VGCCs in pituitary somatotrophs. We next discuss the possible involvement of Ca2+ channelopathies in pituitary disease and the potential use of Ca2+ channel blockers to treat pituitary disease. Various types of VGCCs exist in pituitary cells. However, because L-type Ca2+ channels (LTCCs) contribute the major component to Ca2+ influx in somatotrophs, lactotrophs, and corticotrophs, we focused on these channels. An increasing number of studies in recent years have linked genetic missense mutations in LTCCs to diseases of the human cardiovascular, nervous, and endocrine systems. These disease-associated genetic mutations occur at homologous functional positions (activation gates) in LTCCs. Thus, it is plausible that similar homologous missense mutations in pituitary LTCCs can cause abnormal hormone secretion and underlying pituitary disorders. The existence of LTCCs in pituitary cells opens questions about their sensitivity to dihydropyridines, a group of selective LTCC blockers. The dihydropyridine sensitivity of pituitary cells, as with any other excitable cell, depends primarily on two parameters: the pattern of their electrical activity and the dihydropyridine sensitivity of their LTCC isoforms. These two parameters are discussed in detail in relation to somatotrophs. These discussions are also relevant to lactotrophs and corticotrophs. High dihydropyridine sensitivity may facilitate their use as drugs to treat pituitary oversecretion disorders such as acromegaly, hyperprolactinemia, and Cushing disease.

Cushing's syndrome: comparison between Cushing's disease and adrenal Cushing's

PURPOSE

The most common etiology of Cushing's syndrome (CS) is an ACTH-producing pituitary adenoma (pitCS), reported as 2-3 times more frequent than primary adrenal CS (adrCS). We aimed to analyze and compare features of patients with pitCS and adrCS.

METHODS

A retrospective file review of 196 consecutive patients (age 46.8 ± 15.6 years, 76% female) diagnosed with CS in 2000-2017 and followed for 5.2 ± 4.2 years; 109 (55.6%) had pitCS and 76 (38.8%) adrCS. Epidemiologic, clinical and biochemical factors were compared between and within the pitCS and adrCS groups.

RESULTS

The relative proportion of pitCS to adrCS (1.4) was lower than previously reported and gradually decreased during the study years to only 1.2 in 2012-2017. The most common reason for CS screening was weight-gain in the pitCS group (48.6%) and adrenal incidentaloma in the adrCS group (39.5%). The pitCS patients were diagnosed at younger age (42.5 ± 15.1 vs. 51.6 ± 15.1 years, p < 0.001) and had lower prevalence of hypertension (51.4 vs. 74%, p = 0.005). There was no between-group difference in severity of hypercortisoluria. Within the adrCS group, patients diagnosed after detection of an adrenal incidentaloma had milder hypercortisoluria than the remaining patients, presented with smaller adrenal lesions (35.9 ± 16.3 vs. 49.1 ± 33.7 cm, p = 0.04), and received post-adrenalectomy glucocorticoid treatment for shorter periods (13 ± 11.6 vs. 31 ± 40 months, p = 0.04).

CONCLUSIONS

The relative proportion of adrCS to pitCS is rising, probably because of an increasing detection of cortisol-secreting adrenal incidentalomas associated with milder hypercortisolism. There is no difference between pitCS and adrCS in the severity of hypercortisoluria, although significant clinical differences were found.

A variable course of Cushing's disease in a 7 year old: diagnostic dilemma

Background Cushing's syndrome (CS) or hypercortisolism results from disruption of the hypothalamus-pituitary-adrenal (HPA) axis with the resultant increase in the circulating serum and urinary cortisol levels and lack of cortisol circadian rhythm. The resultant effects cause the physical manifestation of hypercortisolism. The appearance of Cushing's disease in children is insidious, the most common features being growth failure, obesity, early puberty and facial appearance. Case presentation We report a case of a 7-year-old male with a very unusual course of the disease, which could have led to diagnostic delays.

Prognostic Factors of Long-Term Remission After Surgical Treatment of Cushing's Disease

Transsphenoidal surgery is the main treatment of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. Although biochemical remission occurs in most patients undergoing operations at specialized centers, the recurrence risk is significant. Visualization of microadenomas on preoperative imaging and confirmation of ACTH-positive adenomas have been associated with higher remission rates. Low cortisol levels in the first 2 weeks postoperatively have been associated with durable remission; however, recurrence cannot be excluded by any cortisol threshold. The decision to perform a pituitary reoperation is based on this parameter; the protocols are institution specific. Patients with Cushing's disease warrant lifelong endocrinologic surveillance.

Coexistent Pituitary Adenoma with Rathke's Cleft Cyst: A Case Series

OBJECTIVE

Co existent pituitary adenoma and Rathke's cleft cyst (RCC) is a rare entity. Purpose of this study is to describe the clinical presentation, imaging findings, and management of patients with this combination.

METHODS

Retrospective review of records from a single tertiary care center for a period of three years [2009-2012].

RESULTS

Out of the total 284 pituitary adenoma patients in the study period, there were four patients one each of Cushing's disease, acromegaly, prolactinoma and non-secretory pituitary adenoma with coexisting RCC in all. Three of these were diagnosed to have coexisting RCC in preoperative MRI. All of them underwent transphenoidal excision of the lesions. Histopathology confirmed the collision sellar lesions in all four.

CONCLUSIONS

It is difficult to diagnose coexisting RCC preoperatively due to variable size, position and signal intensity. However when a nonenhancing cyst is incidentally detected by MRI in a patient with pituitary adenoma, the possibility of a coexisting RCC should be considered.

Consensus-driven in-hospital cortisol assessment after ACTH-secreting pituitary adenoma resection

PURPOSE

Remission from Cushing disease (CD) after pituitary adenoma resection may be predicted by a postoperative reduction in serum cortisol level. A 2008 consensus statement recommends assessing morning cortisol levels during the first postoperative week, and replacing glucocorticoid (GC) if cortisol nadir of < 2 or < 5 µg/dL is achieved. We sought to evaluate adherence to consensus recommendations following adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma resection at our tertiary medical center, and assess time to cortisol nadir to better define the window for assessment and intervention.

METHODS

We retrospectively analyzed data extracted from in-hospital electronic medical records for CD surgeries between January 1991 and September 2015. We compared cortisol levels and collection times, ACTH measurement, and postoperative and discharge GC treatment before and after consensus statement publication in July 2008.

RESULTS

107 surgeries were performed in 92 patients with CD. After 2008, more surgeries had at least one cortisol value assessed (67.9% before vs. 91.3% after, p = 0.033), with median initial cortisol measurement at 14 h post-surgery. However, ACTH measurement remained unchanged (42.9% vs. 43.5%; p > 0.99). Cortisol collection during GC treatment tended to increase (32.7% vs. 57.1%; p = 0.068). Of surgeries performed without prior GC treatment, 31.7 and 55.0% had a cortisol nadir of < 2 and < 5 µg/dL, respectively, within 72 h postoperative.

CONCLUSIONS

Our physicians were more diligent in measuring in-hospital postoperative cortisol levels consistent with 2008 consensus recommendations. Better management of cortisol measurements and their timing is an opportunity for improvement.

Long-term outcomes of children treated for Cushing's disease: a single center experience

PURPOSE

Pediatric Cushing's disease (CD) is rare and there are limited data on the long-term outcomes. We assessed CD recurrence, body composition, pituitary function and psychiatric comorbidity in a cohort of pediatric CD patients.

METHODS

Retrospective review of 21 CD patients, mean age at diagnosis 12.1 years (5.7-17.8), managed in our center between 1986 and 2010. Mean follow-up from definitive treatment was 10.6 years (2.9-27.2).

RESULTS

Fifteen patients were in remission following transsphenoidal surgery (TSS) and 5 were in remission following TSS + external pituitary radiotherapy (RT). One patient underwent bilateral adrenalectomy (BA). CD recurrence occurred in 3 (14.3 %) patients: 2 at 2 and 6 years after TSS and 1 7.6 years post-RT. The BA patient developed Nelson's syndrome requiring pituitary RT 0.6 years post-surgery. Short-term growth hormone deficiency (GHD) was present in 14 patients (81 % patients tested) (11 following TSS and 3 after RT) and 4 (44 % of tested) had long-term GHD. Gonadotropin deficiency caused impaired pubertal development in 9 patients (43 %), 4 requiring sex steroid replacement post-puberty. Four patients (19 %) had more than one pituitary hormone deficiency, 3 after TSS and 1 post-RT. Five patients (24 %) had long-term psychiatric co-morbidities (cognitive dysfunction or mood disturbance). There were significant long-term improvements in growth, weight and bone density but not complete reversal to normal in all patients.

CONCLUSIONS

The long-term consequences of the diagnosis and treatment of CD in children is broadly similar to that seen in adults, with recurrence of CD after successful treatment uncommon but still seen. Pituitary hormone deficiencies occurred in the majority of patients after remission, and assessment and appropriate treatment of GHD is essential. However, while many parameters improve, some children may still have mild but persistent defects.

POSTSURGICAL RECURRENT CUSHING DISEASE: CLINICAL BENEFIT OF EARLY INTERVENTION IN PATIENTS WITH NORMAL URINARY FREE CORTISOL

OBJECTIVE

To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC).

METHODS

The design was a single-center, retrospective chart review. Patients treated by the authors from 2008-2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST).

RESULTS

We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements.

CONCLUSION

LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone CD = Cushing disease CS = Cushing syndrome CV = coefficient of variation DST = dexamethasone suppression test IPSS = inferior petrosal sinus sampling LNSC = late-night salivary cortisol QoL = quality of life TSS = transsphenoidal adenoma resection UFC = urinary free cortisol.

Clinical management of critically ill patients with Cushing's disease due to ACTH-secreting pituitary macroadenomas: effectiveness of presurgical treatment with pasireotide

The management of critically ill Cushing's disease (CD) patients is extremely challenging. Pasireotide is indicated for the treatment of CD patients when pituitary surgery is unfeasible or has not been curative, but no data are available about the use of this drug as pre-operative treatment in critically ill patients. We report the effects of presurgical pasireotide therapy in CD patients in whom hypercortisolism caused life-threatening hypokalemia, alkalosis, and cardio-respiratory complications precluding surgical approach. Clinical, biochemical, and radiological data of two critically ill patients with ACTH-secreting pituitary macroadenoma, before and during first-line presurgical pasireotide treatment (600 μg s.c. bid). During the first 21 days of treatment, pasireotide therapy induced a rapid, partial decrease of plasma ACTH, serum cortisol, and urinary free cortisol levels, with the consequent normalization of serum potassium concentration and arterial blood gases parameters, in both the patients. They did not experience unmanageable side effects and underwent endoscopic transsphenoidal surgery after 4 weeks of effective treatment. Pre-operative MRI evaluation did not show pituitary tumor shrinkage. Surgical cure of CD was obtained in the first patient, while debulking allowed the pharmacological control of hypercortisolism in the second case. We suggest that pasireotide can induce a rapid improvement of clinical and metabolic conditions in critically ill CD patients in whom surgical approach is considered hazardous and need to be delayed.

Influence of the hypothalamic-pituitary-adrenal axis dysregulation on the metabolic profile of patients affected by diabetes mellitus-associated late onset hypogonadism

BACKGROUND AND AIMS

Functional hypercortisolism (FH) is generated by clinical states able to chronically activate the hypothalamic-pituitary-adrenal (HPA) axis [e.g. diabetes mellitus (DM)]. No study has evaluated FH influence in worsening the metabolic profile of male patients affected by DM-associated hypogonadism. In this retrospective work, we assess the possible association between HPA axis-dysregulation and cardiovascular risk factors in men simultaneously affected by DM and late-onset hypogonadism (LOH).

METHODS AND RESULTS

Fourteen DM and LOH subjects affected by FH (Hypercort-DM-LOH) and fourteen DM and LOH subjects who were not suffering from FH (Normocort-DM-LOH) were retrospectively considered. Clinical, hormonal and metabolic parameters were retrieved. All metabolic parameters, except for systolic blood pressure, were significantly worse in Hypercort-DM-LOH than in Normocort-DM-LOH. After adjustment for body mass index, waist and total testosterone, Hypercort-DM-LOH subjects showed significantly worse metabolic parameters than Normocort-DM-LOH ones. In Normocort-DM-LOH, no significant correlation between general/hormonal parameters and metabolic variables was present. In Hypercort-DM-LOH, positive and significant correlations of cortisol area under the curve (AUC) after corticotropin releasing hormone with glycemia, triglycerides and blood pressure were evident; on the other hand, negative and significant correlation was present between cortisol AUC and high density lipoprotein (HDL) cholesterol. The associations of AUC cortisol with glycemia, HDL cholesterol and diastolic blood pressure (DBP) were further confirmed at quantile regression after adjustment for therapy.

CONCLUSIONS

FH may determine a worsening of the metabolic profile in DM-associated hypogonadism.

Clinical significance of screening for subclinical Cushing's disease in patients with pituitary tumors

Cushing's syndrome (CS) is a clinical state caused by chronic excess of glucocorticoid, and results in hypertension, impaired glucose tolerance, and dyslipidemia. Recently, a mild state of pituitary CS without typical Cushingoid appearance (subclinical Cushing's disease; SCD) has been identified. However, the true prevalence of SCD and its effect on metabolic disorders remain obscure. The aim of this prospective study was to determine the prevalence of SCD according to the guideline proposed by the working group of the Japanese Ministry of Health, Welfare and Labor, and to assess the outcome of surgery on metabolic disorders. The prevalence of SCD was investigated in 105 consecutive patients diagnosed with pituitary adenomas by MRI. ACTH-dependent hypercortisolism was diagnosed based on the results of the 0.5 mg dexamethasone suppression test (serum cortisol >3.0 μg/dL) plus one positive finding of the following two tests: midnight serum cortisol level >5.0 μg/dL or ACTH increase >50% after 1-deamino-5-D-arginine vasopressin (DDAVP) challenge. The final diagnosis of SCD was established by positive staining for ACTH in surgically-excised pituitary adenoma. Three patients (4.8%) were diagnosed with SCD among 62 patients with pituitary adenoma. Transsphenoidal adenomectomy partially resulted in improvement of blood pressure and glucose metabolism in SCD patients. Our results emphasize the importance of SCD screening in patients with pituitary tumors, especially in those patients with metabolic disorders.

Cushing Disease After Treatment of Nonfunctional Pituitary Adenoma: A Case Report and Literature Review

We describe a very rare case of nonfunctional pituitary adenoma (NFPA) that exhibited corticotrophic activity after resection and radiotherapy. The possible mechanisms of the transformation from NFPA to Cushing disease (CD) are discussed.A 43-year-old man presented with impaired vision, bilateral frontal headaches, and hyposexuality. He had no symptoms suggestive of hypercortisolism, and 8 am plasma cortisol concentration was 67.88 ng/mL. Brain imaging revealed a 15 × 15 × 21-mm sellar mass suggestive of a macroadenoma. The tumor was resected by transsphenoidal surgery and identified by immunohistochemical analysis as a chromophobic adenoma that did not stain for pituitary hormones. The patient was treated with prednisone and levothyroxine replacement therapy. After a third recurrence, the patient presented with clinical features and physical signs of Cushing syndrome. Plasma adrenocorticotropic hormone (ACTH) and cortisol concentrations were elevated, and there was a loss of circadian rhythms. Inferior petrosal sinus sampling after desmopressin showed the central-peripheral ACTH ratio was greater than 3:1. A repeat transsphenoidal resection was undertaken. Immunohistochemistry revealed ACTH positivity. Three months following surgery, imaging showed little residual tumor, but plasma ACTH remained elevated. He was referred for postoperative Gamma Knife radiotherapy.The immunological activity and biological features of the hormones secreted from a pituitary adenoma vary with time. Because long-term outcomes are unpredictable, postoperative follow-up is essential to detect postoperative transformation from NFPA to CD.

A critical reappraisal of bilateral adrenalectomy for ACTH-dependent Cushing's syndrome

OBJECTIVE

Our aim was to review short- and long-term outcomes of patients treated with bilateral adrenalectomy (BADx) in ACTH-dependent Cushing's syndrome.

METHODS

We reviewed the literature and analysed our experience with 53 patients treated with BADx since 1990 in our institution.

RESULTS

BADx is considered if ACTH-dependent Cushing's syndrome is refractory to other treatment modalities. In Cushing's disease (CD), BADx is mainly used as an ultima ratio after transsphenoidal surgery and medical therapies have failed. In these cases, the time span between the first diagnosis of CD and treatment with BADx is relatively long (median 44 months). In ectopic Cushing's syndrome, the time from diagnosis to BADx is shorter (median 2 months), and BADx is often performed as an emergency procedure because of life-threatening complications of severe hypercortisolism. In both situations, BADx is relatively safe (median surgical morbidity 15%; median surgical mortality 3%) and provides excellent control of hypercortisolism; Cushing's-associated signs and symptoms are rapidly corrected, and co-morbidities are stabilised. In CD, the quality of life following BADx is rapidly improving, and long-term mortality is low. Specific long-term complications include the development of adrenal crisis and Nelson's syndrome. In ectopic Cushing's syndrome, long-term mortality is high but is mostly dependent on the prognosis of the underlying malignant neuroendocrine tumour.

CONCLUSION

BADx is a relatively safe and highly effective treatment, and it provides adequate control of long-term co-morbidities associated with hypercortisolism.

A role for 11C-methionine PET imaging in ACTH-dependent Cushing's syndrome

OBJECTIVE

We report our experience of functional imaging with (11)C-methionine positron emission tomography-computed tomography (PET-CT) co-registered with 3D gradient echo (spoiled gradient recalled (SPGR)) magnetic resonance imaging (MRI) in the investigation of ACTH-dependent Cushing's syndrome.

DESIGN

Twenty patients with i) de novo Cushing's disease (CD, n=10), ii) residual or recurrent hypercortisolism following first pituitary surgery (±radiotherapy; n=8) or iii) ectopic Cushing's syndrome (n=2) were referred to our centre for functional imaging studies between 2010 and 2015. Six of the patients with de novo CD and five of those with persistent/relapsed disease had a suspected abnormality on conventional MRI.

METHODS

All patients underwent (11)C-methionine PET-CT. For pituitary imaging, co-registration of PET-CT images with contemporaneous SPGR MRI (1 mm slice thickness) was performed, followed by detailed mapping of (11)C-methionine uptake across the sella in three planes (coronal, sagittal and axial). This allowed us to determine whether suspected adenomas seen on structural imaging exhibited focal tracer uptake on functional imaging.

RESULTS

In seven of ten patients with de novo CD, asymmetric (11)C-methionine uptake was observed within the sella, which co-localized with the suspected site of a corticotroph microadenoma visualised on SPGR MRI (and which was subsequently confirmed histologically following successful transsphenoidal surgery (TSS)). Focal (11)C-methionine uptake that correlated with a suspected abnormality on pituitary MRI was seen in five of eight patients with residual or recurrent Cushing's syndrome following first TSS (and pituitary radiotherapy in two cases). Two patients elected to undergo repeat TSS with histology confirming a corticotroph tumour in each case. In two patients with the ectopic ACTH syndrome, (11)C-methionine was concentrated in sites of distant metastases, with minimal uptake in the sellar region.

CONCLUSIONS

(11)C-methionine PET-CT can aid the detection of ACTH-secreting tumours in Cushing's syndrome and facilitate targeted therapy.

Effects of Carbenoxolone on the Canine Pituitary-Adrenal Axis

Cushing’s disease caused by pituitary corticotroph adenoma is a common endocrine disease in dogs. A characteristic biochemical feature of corticotroph adenomas is their relative resistance to suppressive negative feedback by glucocorticoids. The abnormal expression of 11beta-hydroxysteroid dehydrogenase (11HSD), which is a cortisol metabolic enzyme, is found in human and murine corticotroph adenomas. Our recent studies demonstrated that canine corticotroph adenomas also have abnormal expression of 11HSD. 11HSD has two isoforms in dogs, 11HSD type1 (HSD11B1), which converts cortisone into active cortisol, and 11HSD type2 (HSD11B2), which converts cortisol into inactive cortisone. It has been suggested that glucocorticoid resistance in corticotroph tumors is related to the overexpression of HSD11B2. Therefore it was our aim to investigate the effects of carbenoxolone (CBX), an 11HSD inhibitor, on the healthy dog’s pituitary-adrenal axis. Dogs were administered 50 mg/kg of CBX twice each day for 15 days. During CBX administration, no adverse effects were observed in any dogs. The plasma adrenocorticotropic hormone (ACTH), and serum cortisol and cortisone concentrations were significantly lower at day 7 and 15 following corticotropin releasing hormone stimulation. After completion of CBX administration, the HSD11B1 mRNA expression was higher, and HSD11B2 mRNA expression was significantly lower in the pituitaries. Moreover, proopiomelanocortin mRNA expression was lower, and the ratio of ACTH-positive cells in the anterior pituitary was also significantly lower after CBX treatment. In adrenal glands treated with CBX, HSD11B1 and HSD11B2 mRNA expression were both lower compared to normal canine adrenal glands. The results of this study suggested that CBX inhibits ACTH secretion from pituitary due to altered 11HSD expressions, and is potentially useful for the treatment of canine Cushing’s disease.

Therapy of endocrine disease: outcomes in patients with Cushing's disease undergoing transsphenoidal surgery: systematic review assessing criteria used to define remission and recurrence

OBJECTIVE

A number of factors can influence the reported outcomes of transsphenoidal surgery (TSS) for Cushing's disease - including different remission and recurrence criteria, for which there is no consensus. Therefore, a comparative analysis of the best treatment options and patient management strategies is difficult. In this review, we investigated the clinical outcomes of initial TSS in patients with Cushing's disease based on definitions of and assessments for remission and recurrence.

METHODS

We systematically searched PubMed and identified 44 studies with clear definitions of remission and recurrence. When data were available, additional analyses by time of remission, tumor size, duration of follow-up, surgical experience, year of study publication and adverse events related to surgery were performed.

RESULTS

Data from a total of 6400 patients who received microscopic TSS were extracted and analyzed. A variety of definitions of remission and recurrence of Cushing's disease after initial microscopic TSS was used, giving broad ranges of remission (42.0-96.6%; median, 77.9%) and recurrence (0-47.4%; median, 11.5%). Better remission and recurrence outcomes were achieved for microadenomas vs macroadenomas; however, no correlations were found with other parameters, other than improved safety with longer surgical experience.

CONCLUSIONS

The variety of methodologies used in clinical evaluation of TSS for Cushing's disease strongly support the call for standardization and optimization of studies to inform clinical practice and maximize patient outcomes. Clinically significant rates of failure of initial TSS highlight the need for effective second-line treatments.

Approach to the postoperative patient with Cushing's disease

INTRODUCTION

Cushing's disease is a neuroendocrine disorder marked by hypercortisolemia secondary to overproduction of ACTH by a corticotropic pituitary adenoma. Due to the diverse and deleterious effects of hypercortisolemia including diabetes mellitus, hypertension, and cardiovascular disease, prompt and accurate diagnosis followed by surgical resection of the responsible corticotropic adenoma is critical.

METHODS

In the following review, we present a focused synopsis of recently published data and management strategies for the post-operative Cushing's disease patient with a particular focus on studies examining perioperative complications, establishment of biochemical remission, factors associated with disease remission, and predictors of recurrence.

CONCLUSIONS

Although no standard definition of remission exists, we suggest measurement of serum cortisol level on the morning of postoperative day 1 given the preponderance of evidence in the published literature suggesting its association with long-term remission and relatively low rates of recurrence. Nevertheless, all patients should be counseled that recurrence can occur in a delayed fashion and that annual endocrine testing should be utilized to track and confirm disease status.

A pitfall in diagnosing Cushing's disease: ectopic ACTH-producing pituitary adenoma in the sphenoid sinus

PURPOSE

To show a rare case of Cushing's disease and possible cause of failed transsphenoidal surgery.

METHOD

We report on a 50-year-old woman suffering from ACTH-dependent Cushing's syndrome. Endocrinological work-up including low-dose/high-dose dexamethasone test (Liddle-test) and CRH test were clearly compatible with pituitary origin. Although an MRI showed no pituitary tumor, CRH-stimulated petrosal sinus sampling revealed a significant central-peripheral gradient in ACTH concentrations, rendering Cushing's disease very likely. The patient underwent transsphenoidal surgery with negative exploration of the pituitary gland. After intraoperative re-evaluation of the preoperative MRI, a "polyp" at the bottom of the sphenoid sinus was identified. The intraoperative microscopic aspect as well as instantaneous sections and cytology of a biopsy confirmed an adenoma, which was then removed. Histological analysis demonstrated an ACTH-producing pituitary adenoma adjacent to respiratory mucous membrane consisting of ciliated epithelium with submucous connective tissue. Postoperatively, ACTH concentrations were decreased and intermittent hydrocortisone substitution treatment was initiated. At the 3-month follow up, Cushing's stigmata were found to be alleviated and the hydrocortisone dosage could be reduced.

CONCLUSION

Ectopic pituitary adenoma tissue causing Cushing's disease is extremely rare but a potential cause for surgical failure or re-evaluation.

Pituitary-directed medical therapy in Cushing's disease

Transsphenoidal surgery remains the first line therapy in Cushing's disease, but a large number of patients will not be cured or disease will recur over time. Repeat pituitary surgery, bilateral adrenalectomy, and radiation have limitations with respect to efficacy and/or side effects. Therefore, there is a clear need for an effective medical treatment. The studies reviewed here suggest a role for pituitary-directed therapies, applying multireceptor ligand somatostatin analogs like pasireotide or second-generation dopamine agonists. Retinoic acid has been also studied in a small prospective study. These compounds target ACTH-secretion at the pituitary level and possibly inhibit corticotrope proliferation. Specific side effects of these compounds need to be considered, especially when used as long-term therapy. These novel approaches could provide options for treatment of patients in whom surgery has failed or is not possible, and while awaiting effects of radiation therapy. Preoperative use to decrease cortisol excess, potentially reducing perioperative complications, needs to be further studied.

Medical therapy for Cushing's disease: adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers

Morbidity and mortality in Cushing's disease (CD) patients are increased if patients are not appropriately treated. Surgery remains the first line therapy, however the role of medical therapy has become more prominent in patients when biochemical remission is not achieved/or recurs after surgery, while waiting effects of radiation therapy or when surgery is contraindicated. Furthermore, use of preoperative medical therapy has been also recognized. In addition to centrally acting therapies (reviewed elsewhere in this special issue), adrenal steroidogenesis inhibitors, and glucocorticoid receptor antagonists are frequently used. A PubMed search of all original articles or abstracts detailing medical therapy in CD, published within 12 months (2013-2014), were identified and pertinent data extracted. Although not prospectively studied, ketoconazole and metyrapone have been the most frequently used medical therapies. A large retrospective ketoconazole study showed that almost half of patients who continued on ketoconazole therapy achieved biochemical control and clinical improvement; however almost 20% discontinued ketoconazole due to poor tolerability. Notably, hepatotoxicity was usually mild and resolved after drug withdrawal. Etomidate remains the only drug available for intravenous use. A new potent inhibitor of both aldosterone synthase and 11β-hydroxylase, following the completion of a phase II study LCI699 is being studied in a large phase III with promising results. Mifepristone, a glucocorticoid receptor antagonist, has been approved for hyperglycemia associated with Cushing's syndrome based on the results of a prospective study where it produced in the majority of patients' significant clinical and metabolic improvement. Absence of both a biochemical marker for remission and/or diagnosis of adrenal insufficiency remain, however, a limiting factor. Patient characteristics and preference should guide the choice between different medications in the absence of clinical trials comparing any of these therapies. Despite significant progress, there is still a need for a medical therapy that is more effective and with less adverse effects for patients with CD.

Medical combination therapies in Cushing's disease

INTRODUCTION

There has been growing interest on medical therapy for the management of Cushing's disease (CD), particularly in cases of persistent or recurrent hypercortisolism. Ketoconazole, an inhibitor of adrenal steroidogenesis, is the most widely used drug, whereas cabergoline and pasireotide are the most promising centrally acting agents. The main purpose of this review article is to highlight the options of medical treatment for CD, with a special emphasis on combination therapies, a topic that has only been addressed by a limited number of studies.

CONCLUSIONS

According to the results of these studies, combination therapies involving medications with additive or synergistic effects on ACTH and cortisol secretion seem quite attractive as they yield higher probability of longterm control of the hypercortisolism at lower doses, a lower incidence of side-effects, and possibly a lower rate of treatment escapes. Currently, ketoconazole, cabergoline, and pasireotide are the best drugs to be prescribed in combination.

Surgical management of Cushing's disease

BACKGROUND

Transsphenoidal selective adenomectomy is the first-line treatment for Cushing's disease. At experienced centers, early remission rates after transsphenoidal surgery range from 65 to 98%, however disease relapse frequently occurs with rates ranging from 2 to 35% at long-term follow up.

METHODS

This article discusses recently reported studies on the surgical outcomes from transsphenoidal surgery for Cushing's disease.

CONCLUSIONS

One of the keys to a successful long-term surgical outcome is meticulous dissection using the adenoma's pseudocapsule as a surgical plane for complete resection. MRI-negative and invasive ACTH-secreting adenomas pose particular challenges for pituitary surgeons.