Update on radiation therapy in patients with Cushing's disease

INTRODUCTION

Radiation therapy is an important therapy for patients with Cushing's disease who are not in remission or relapse after transsphenoidal pituitary surgery and are not considered surgical candidates. The development of stereotactic radiation therapy, using gamma knife, linear accelerators or proton beam based methods, has enabled selective radiation delivery to the target while minimizing exposure of healthy tissues. In patients whose tumors are sufficiently distant from the optic apparatus, stereotactic radiation therapy can be delivered in a single session, a procedure termed radiosurgery, which significantly improves patient convenience.

METHODS

Original articles on radiation therapy in Cushing's disease, published during the past 12 months (2013-2014), were identified and pertinent data extracted.

RESULTS

Recent studies have reported on the outcomes of patients with Cushing's disease who received mostly stereotactic radiation therapy. While tumor control has been excellent, biochemical remission was less consistently achieved. Some studies suggested that stereotactic radiation may lead to biochemical remission faster than conventional radiation therapy. In addition, retrospective data have suggested that withdrawing medical therapy around the time stereotactic radiation therapy is administered might lead to a faster biochemical response. Regardless of the radiation therapy method, biochemical recurrences may develop and these patients are at long-term risk of developing anterior hypopituitarism and require lifelong periodic endocrine follow-up. Other, less frequent complications may include cranial neuropathies, secondary tumor formation or temporal lobe necrosis. It is plausible that complications may be less frequent after stereotactic radiation therapy, but this requires confirmation.

CONCLUSIONS

Radiation therapy is an effective second line therapy in patients with Cushing's disease. Ongoing refinements in delivery of radiation therapy are anticipated to lead to improved patient outcomes, but long-term follow-up data, including adequate control groups, are needed to fully investigate this possibility.

Bilateral adrenalectomy for Cushing's disease

PURPOSE

Review the indications, outcomes, and consequences of bilateral adrenalectomy (BLA) in patients with Cushing's disease.

METHODS

A literature review was performed.

RESULTS

The primary therapy for Cushing's disease is surgery, with medical therapy and radiation therapy relegated to an adjuvant role. BLA is indicated in cases of persistent disease following pituitary surgery or in situations where rapid normalization of hypercortisolism is required. When performed via the laparoscopic approach, BLA is associated with a significantly reduced morbidity compared to the traditional, open approach. Following BLA, patients are at risk for adrenal crisis and the concern of Nelson's syndrome. However, BLA leads to a rapid resolution of the signs and symptoms of CS and leads to an improved long-term quality of life.

CONCLUSION

BLA should be considered in the treatment algorithm for patients with persistent CD after failed pituitary surgery, especially in patients who have severe consequences of hypercortisolism or desire pregnancy.

Screening for ACTH-dependent hypercortisolism in patients affected with pituitary incidentaloma

CONTEXT

Pituitary incidentalomas (PIs) are commonly encountered in clinical practice. The management of these asymptomatic pituitary lesions is still controversial. Systematic screening for subclinical or mild ACTH-dependent hypercortisolism (AH) is not presently recommended, due to the limited data available thus far on the epidemiological and clinical relevance of this condition in patients with PIs. As subclinical hypercortisolism (SH) was considered to be associated with chronic complications of overt cortisol excess, such as hypertension, diabetes, and osteoporosis, this disorder should be diagnosed at the early stage.

OBJECTIVE

The objective of this study was to evaluate the prevalence of hypercortisolism in a population of subjects with PIs.

DESIGN, SUBJECTS, AND METHODS

A total of 68 consecutive patients (48 females and 20 males, aged 18-82 years) without clinically overt hypercortisolism, who were referred for evaluation of PIs between January 2010 and March 2013, were prospectively investigated for AH. Pituitary hypercortisolism was diagnosed in the presence of cortisol >50 nmol/l after 1 mg dexamethasone suppression test, non-suppressed ACTH, and the additional finding of one of the following: urinary free cortisol (UFC) >193 nmol/24 h, and midnight serum and salivary cortisol levels >207 and 2.8 nmol/l respectively.

RESULTS

Among patients with PIs, we found a 7.3% rate of pituitary hypercortisolism diagnosed with biochemical criteria and a 4.4% rate of histologically confirmed AH.

CONCLUSIONS

Subclinical or mild hypercortisolism may be more common than generally perceived in patients with PIs.

New potential targets for treatment of Cushing's disease: epithelial growth factor receptor and cyclin-dependent kinases

BACKGROUND

Cushing's disease (CD) is caused by adrenocorticotropic hormone (ACTH)-producing pituitary adenomas (ACTHomas). Drug treatment for CD consists of three strategies: pituitary tumor-targeted therapy, steroidogenesis inhibitors, and glucocorticoid receptor antagonists. All of these strategies are under development, and several new drugs have recently been approved for clinical use or are being tested in clinical trials. Pituitary-targeted drugs are a particularly important method in the treatment of CD. Available pituitary tumor-targeted drugs include a dopamine receptor agonist and a somatostatin analog. Since disrupted cell cycle signaling is clearly associated with pathogenesis of ACTHomas which express active forms of epithelial growth factor receptor (EGFR), cyclins, and the catalytic subunit of cyclin-dependent kinases (CDKs), we focused on these molecules as therapeutic targets for ACTHomas.

METHODS

In this review, a literature search were performed using PubMed with following terms; Cushing's disease, EGFR, CDKs, cell cycle, and targeted therapy.

CONCLUSION

Accumulating evidence demonstrates that EGFR and cyclin E-CDK2 may be promising targets for treating ACTHomas.

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.

Current status on histological classification in Cushing's disease

INTRODUCTION

Managing Cushing's disease remains a challenge. Surgery is the first option of treatment and it offers a high success rate. Even in cases where biochemical remission is not achieved, it is crucial to obtain surgical tissue for morphological diagnosis because the therapeutic approach can be modified according to the findings.

MATERIALS AND METHODS

A literature search was performed using PubMed for information regarding pathology and Cushing's disease.

RESULTS

The histopathological features found in the pituitary gland of patients with Cushing's disease are presented.

CONCLUSION

Different subtypes of ACTH-producing pituitary tumors are recognized and characterized. The significance of finding a normal pituitary gland with or without Crooke's changes is also discussed.

Accuracy of repeated measurements of late-night salivary cortisol to screen for early-stage recurrence of Cushing's disease following pituitary surgery

OBJECTIVE

The performance of late-night salivary cortisol (LNSC) to accurately screen for postoperative recurrence of Cushing's disease (CD) at an early stage is unknown. The aim of this study was to compare the accuracy of multiple sampling strategies to suggest the optimal number of LNSC samples needed for diagnosing post-surgical recurrences of CD at an early stage.

DESIGN

Retrospective analysis in a single centre.

PATIENTS AND MEASUREMENTS

Thirty-six patients in surgical remission of CD had successive measurements of LNSC, defined as 'sequences', using a locally modified RIA assay as part of long-term follow-up (69·2 ± 10·6 months). Patients underwent an extensive biochemical evaluation within 3 months before or after a sequence of saliva sampling and were classified as being in remission or in early-stage recurrence. The accuracy of three diagnostic strategies combining two, three or four LNSC results from a sequence was estimated using areas under the ROC curves (AUC), sensitivity, specificity and predictive values.

RESULTS

Forty-four sequences of LNSC measurements were available. Fifty-two percent of sequences were performed during early-stage recurrence. The intrasequence variability of LNSC was higher during recurrence than during remission (medians of SDs: 2·1 vs 0·5 nm; P < 0·0001). AUCs from ROC curves ranged from 0·93 to 0·96 depending on the strategy. For 90% sensitivities, the best specificities (92·9% and 90·9%) were achieved by strategies taking into account three or four measurements summarized either by their mean or their maximum value.

CONCLUSIONS

Increase in LNSC concentration is an early abnormality during post-surgical recurrence of CD. However, due to a major within-patient variability of LNSC from 1 day to another, a screening strategy using three or four samples collected on successive days may be recommended to detect early-stage recurrence of CD with a high accuracy.

Nasally located ectopic ACTH-secreting pituitary adenoma (EAPA) causing Nelson's syndrome: diagnostic challenges

PURPOSE

We report the first case of an Ectopic adrenocorticotrophin (ACTH)-secreting pituitary adenoma (EAPA) located within the posterior nasal septum associated with Nelson's syndrome, which eluded diagnosis for over a decade. In this report, we explore the reasons for such diagnostic difficulty and suggest ways in which an earlier diagnosis may be made.

METHODS AND RESULTS

A 19 years old Lebanese man presented in 2000, with overt Cushing's syndrome confirmed with markedly elevated urine free cortisols and failed dexamethasone suppression tests. An unsuppressed ACTH and a possible 5 mm adenoma on MRI (Magnetic Resonance Imaging) pituitary suggested Cushing's disease. The patient underwent trans-sphenoidal surgery (TSS), but histology revealed normal pituitary tissue and Cushing's syndrome persisted. A repeat MRI pituitary showed no anomaly, and extensive investigations failed to locate an ectopic lesion. Subsequently a bilateral adrenalectomy was performed. Over the ensuing years, the patient developed Nelson's syndrome with hyperpigmentation and markedly elevated ACTH levels. Repeated high dose dexamethasone suppression tests, corticotrophin releasing hormone (CRH) tests, and CRH stimulated inferior petrosal sinus samplings (IPSS) suggested a pituitary origin of the ACTH. Two further TSS were unsuccessful. The pituitary was irradiated. Subsequent review of his previous MRIs revealed an enlarging mass within the posterior nasal septum, which was excised in 2011. The histology confirmed the diagnosis of an EAPA within the nasal septum.

CONCLUSION

Ectopic ACTH-secreting pituitary adenomas can occur not only along the developmental route of Rathke's pouch, but other aberrant locations giving a clinical and biochemical picture identical to Cushing's disease or Nelson's syndrome. Clinicians should suspect an EAPA, when a central ACTH source seems to be apparent with no obvious pituitary adenoma. A detailed MRI involving possible EAPA sites aids in locating these unusual lesions.

Rare case of Cushing's disease due to double ACTH-producing adenomas, one located in the pituitary gland and one into the stalk

We describe a patient affected by Cushing's disease due to the presence of double pituitary adenomas, one located within the anterior pituitary and the other in the infundibulum associated with a remnant of Rakthe's pouch. Cure was achieved only after the infundibulum lesion was surgically removed.

CASE REPORT

A 38-year-old female presented with unexplained weight gain, hirsutism, amenorrhea, asthenia, recurrent cutaneous micotic infections and alopecia. Hormonal studies indicated Cushing's disease and MRI showed an enlarged pituitary gland with a marked and homogeneous enhancement after injection of gadolinium and an enlarged infundibulum with a maximum diameter of 8 mm. As a venous sampling of the inferior petrosal sinus after 10 μg iv desmopressin stimulation revealed a central to peripheral ACTH ratio consistent with a pituitary ACTH-secreting tumor, transphenoidal explorative surgery was performed and a 4-mm pituitary adenoma immunopositive for ACTH was disclosed and removed. Since postoperative hormonal evaluation showed persistent hypercortisolism, confirmed by dynamic tests, the patient again underwent surgery by transcranial access and the infundibulum mass was removed. Histology and immunochemistry were consistent with an ACTH-secreting adenoma. A few months after the second operation, cushingoid features were significantly reverted and symptoms improved.

CONCLUSION

Although Cushing's patients bearing multiple adenomas have already been documented, the presence of two adenomas both immunohistochemically positive for ACTH is a very rare cause of Cushing's disease and this is the first report of a case of double ACTH-producing adenomas, one located in the pituitary gland and one attached to the stalk.

Differentiating between Cushing's disease and pseudo-Cushing's syndrome: comparison of four tests

OBJECTIVE

To evaluate the diagnostic performance of four different tests in order to differentiate between Cushing's disease (CD) and pseudo-Cushing's syndrome (PCS).

METHODS

In this prospective study, a total of 73 patients with clinical features of hypercortisolism and insufficient suppression of serum cortisol after 1 mg overnight dexamethasone and/or an elevated excretion of cortisol in 24-h urine samples were included. The circadian rhythm of serum cortisol levels as well as midnight serum cortisol (MserC) levels were assessed in all 73 patients. Late-night salivary cortisol (LNSC) concentrations were obtained in 44 patients. The dexamethasone-CRH (Dex-CRH) test was performed in 54 patients.

RESULTS

FIFTY-THREE PATIENTS WERE DIAGNOSED WITH CD AND SUBSEQUENTLY TREATED. TWENTY PATIENTS WERE CLASSIFIED AS HAVING PSC. SERUM CORTISOL CIRCADIAN RHYTHM: the diurnal rhythmicity of cortisol secretion was retained in PCS. A cortisol midnight:morning ratio of >0.67 is highly suggestive of CD (positive predictive value (PPV) 100% and negative predictive value (NPV) 73%). MserC concentration >243 nmol/l has a PPV of 98% in predicting true CD (NPV 95%). LNSC level >9.3 nmol/l predicted CD in 94% of patients (NPV 100%). Dex-CRH test: after 2 days of dexamethasone suppression, a CRH-stimulated cortisol level >87 nmol/l (T=15 min) resulted in a PPV of 100% and an NPV of 90%.

CONCLUSION

The Dex-CRH test as well as a single measurement of cortisol in serum or saliva at late (mid-) night demonstrated high diagnostic accuracy in differentiating PCS from true CD.

A somatotropin-producing pituitary adenoma with an isolated adrenocorticotropin-producing pituitary adenoma in a female patient with acromegaly, subclinical Cushing's disease and a left adrenal tumor

A 67-year-old female with hypertension and impaired glucose tolerance was admitted to our hospital because of a typical acromegalic appearance, including large, thickened bulky hands and feet, and a large prominent forehead and tongue. She did not have a Cushingoid appearance, such as a moon-face, buffalo hump, purple striae or central obesity. The laboratory data revealed a serum GH level of 4.6 ng/mL and serum insulin-like growth factor-1 level of 811 ng/mL. The oral glucose tolerance test showed no suppression of the GH values. An endocrine examination showed a lack of circadian rhythmicity of ACTH and cortisol. Cortisol was not suppressed by a low dose of dexamethasone during the suppression test, but was suppressed by a high dose of dexamethasone. A radiological study revealed two isolated adenomas in the pituitary and a left adrenal tumor. These findings strongly suggested a diagnosis of acromegaly with subclinical Cushing's disease and a left adrenal incidentaloma. Transsphenoidal surgery was performed. Hematoxylin and eosin staining showed that the left and right pituitary adenomas were composed of basophilic and acidophilic cells, respectively. Immunohistochemical staining showed the left adenoma to be positive for ACTH and negative for GH. In contrast, the right adenoma was GH-positive and ACTH-negative. This is a rare case of independent double pituitary adenomas with distinct hormonal features. We also provide a review of the previously reported cases of double pituitary adenomas and discuss the etiology of these tumors.

Silent corticotroph adenoma with adrenal cortical choristoma: a rare but distinct morphological entity

This report describes a case of pituitary adenoma with interspersed adrenal cortical cells. The pituitary cells were confirmed to be corticotrophs with Tpit and adrenocorticotropic hormone immunohistochemistry, whereas the adrenal cortical cells were verified to be such with steroidogenic factor-1 (SF-1), inhibin, calretinin, and Melan A staining. The presence of normal adrenal cortical cells in the heterotopic location of the sella fulfills the definition of choristoma. The origin of adrenal cortical cells within a pituitary adenoma remains unexplained. The important role of SF-1 in both pituitary and adrenal cortex may explain a relationship that supports the possibility of an abnormal proliferation and differentiation of uncommitted mesenchymal stem cells within the sella. However, it remains possible that misplaced adrenal cortical cells derived during embryogenesis give rise to this rare but distinct morphological entity that can pose a difficult diagnostic dilemma. The approach to differential diagnosis is discussed.

ACTH-secreting pituitary microadenomas are associated with a higher prevalence of central hypothyroidism compared to other microadenoma types

CONTEXT

Unlike pituitary macroadenomas, microadenomas (micros) are not commonly associated with hypopituitarism. In clinical practice, we have observed that patients with ACTH-secreting micros have a higher than expected prevalence of central hypothyroidism (HT), and we speculated that this effect might be because of glucocorticoid-induced suppression of the hypothalamic-pituitary-thyroid axis.

OBJECTIVE

To determine whether there is a difference in the prevalence of central HT among ACTH micros compared to other types of microadenoma, and if so, to investigate whether this is directly related to the degree of hypercortisolism.

DESIGN, SETTING AND PATIENTS

Retrospective study of 149 newly diagnosed patients with pituitary micros: 34 ACTH-secreting, 72 prolactin-secreting (PRLomas) and 43 clinically nonfunctioning adenomas (NFAs).

MAIN OUTCOMES MEASURES

Prevalence of central HT, correlation between normalized free T4 or TSH vs normalized urinary free cortisol (UFC) or salivary cortisol.

RESULTS

The prevalence of central HT was significantly higher in the ACTH compared to the non-ACTH adenomas: 18% (ACTH), 1% (PRL) and 0% (NFAs). The mean normalized free T4 was lower in the ACTH micros compared to the non-ACTH micros (1·29 ± 0·06 vs 1·50 ± 0·23, P = 0·0001). There was no correlation between the degree of hypercortisolism, as reflected by 24-h urine free cortisol and salivary cortisol, and free T4 or TSH levels among the ACTH adenomas. Similarly, there were no differences in mean UFC or salivary cortisol between ACTH adenomas with and without central HT. Following transsphenoidal adenomectomy, central HT recovered in three of six patients with ACTH micros.

CONCLUSIONS

These findings suggest that patients with ACTH-secreting microadenomas should always, at a minimum, undergo testing for central HT. However, given the potential for recovery of thyroid function following cure of Cushing disease, we recommend withholding thyroid hormone replacement until after pituitary surgery.

Measurements of serum DHEA and DHEA sulphate levels improve the accuracy of the low-dose cosyntropin test in the diagnosis of central adrenal insufficiency

BACKGROUND AND OBJECTIVES

The diagnosis of central adrenal insufficiency (AI) continues to be challenging, especially when it is partial. We have recently demonstrated the value of measuring serum dehydroepiandrosterone sulfate (DHEA-S) in establishing the diagnosis of central AI. The current investigation examined the added value of measuring serum dehydroepiandrosterone (DHEA) levels during low-dose (1 μg) cosyntropin (LDC) stimulation in patients suspected to have central AI.

METHODS

Baseline and LDC-stimulated cortisol, DHEA, and DHEA-S were measured preoperatively in 155 consecutive patients with pituitary masses and 63 healthy subjects. Hypothalamic-pituitary adrenal (HPA) function was normal (NL-HPA) in 97 of the patients and was impaired (impaired HPA) in 58 patients. Patients with NL-HPA underwent surgical removal of the sellar masses and received no glucocorticoids before, during, or after surgery.

RESULTS

Baseline and LDC-stimulated serum cortisol, DHEA, and DHEA-S in patients with NL-HPA were similar to those of normal subjects. In contrast, patients with impaired HPA had lower baseline and LDC-stimulated serum cortisol, DHEA, and DHEA-S levels. There were 18 subjects in the latter group whose LDC-stimulated serum cortisol levels were greater than 18.0 μg/dl. In those 18 subjects, baseline and LDC-stimulated DHEA and DHEA-S levels were similar to the whole group of patients with impaired HPA function. The molar ratio of cortisol to DHEA did not change with LDC stimulation in normal subjects and those with NL-HPA. In contrast, patients with impaired HPA had a higher baseline cortisol to DHEA molar ratio that increased further with LDC stimulation.

CONCLUSIONS

Patients with impaired HPA function have a more severe loss in DHEA secretion than that of glucocorticoids. Measurements of serum DHEA levels during LDC simulation provide additional valuable information that improves the diagnostic accuracy of LDC in patients suspected to have central AI. We recommend the inclusion of DHEA and DHEA-S measurements in the laboratory assessment of HPA function.

Immediate and delayed postoperative morbidity in functional and non-functioning pituitary adenomas

Neurosurgery is the most widely used definite treatment for pituitary tumors, while medical treatments are a good option to improve symptoms, which tend to recur when drugs are stopped. The aim of this study was to assess postsurgical morbidity of secreting pituitary adenomas (adrenocorticotropin hormone -ACTH- and growth hormone -GH- secreting) and non-functioning (NF) adenomas, operated between January 2002 and May 2009. We retrospectively reviewed the data of 94 patients who were operated by the same neurosurgeons and compared the immediate (1st month) and delayed (1st year) complications between the three groups of adenomas. Forty had immediate post-operative complications (42% of NF, 37% of GH-secreting and 48% of ACTH-secreting adenomas). The most frequent complications were transient diabetes insipidus (23%), cerebrospinal fluid leaks (7%), sinusitis and meningitis (2%). Patients with Cushing's disease showed a tendency to have more transient diabetes insipidus and sinusitis compared to NF adenomas (P = 0.071). Ten patients had delayed complications during the first post-operative year (7% of NF, 11% of GH-secreting and 15% of ACTH-secreting), with a greater incidence of arthromyalgias and acute carpal tunnel syndrome in ACTH-secreting adenomas, compared with the other groups (P < 0.05). We conclude, that although ACTH-secreting adenomas are mostly microadenomas (78%) and affect younger patients, they are associated with a greater number of immediate and delayed complications during the first postoperative year (mainly invalidating arthromyalgias and acute carpal tunnel syndrome) compared with larger GH-secreting and NF adenomas, probably related to acute glucocorticoid deprivation after successful surgery.

Clinical features of silent corticotroph adenomas

BACKGROUND

Silent corticotrph adenomas represent a distinct pathological subtype of non-functioning pituitary adenomas that are traditionally believed to carry a more aggressive biological behavior and higher potential for recurrence.

METHODS

We conducted a retrospective review of all silent corticotroph adenomas treated and followed at our institution over the last 10 years. We reviewed clinical, radiological and pathological features. The series was compared to a matched cohort of ACTH-negative, non-functioning adenomas to compare clinical, radiological and pathological features. Our results were compared to the literature.

RESULTS

Twenty patients met our inclusion criteria. Fifty-six percent of the patients were females. Mean age was 51 years (range 24-78 years). Visual dysfunction was the most common clinical presentation (38 %). Thirteen percent of the cases presented with acromegaly secondary to double adenoma (silent corticotroph adenoma and growth hormone adenoma) and 13 % presented with pituitary tumor apoplexy. All the tumors were macroadenomas. Frank cavernous sinus invasion occurred in 31 % of the cases. The patients who presented with acromegaly did not achieve remission postoperatively. In the remaining patients, recurrence occurred in 14 % of the cases over a mean follow-up period of 41 months. Compared to non-functioning adenomas, silent corticotroph adenomas were more likely to bleed (p value 0.014) and have double adenoma (p value 0.047). There was no difference in recurrence rates between silent corticotroph adenomas and non-functioning adenomas (p value 0.647).

CONCLUSION

These results suggest that silent corticotroph adenomas have some unique features compared to non-functioning adenomas. Within the limits of our follow-up duration and sample size and our review of the literature, we would recommend that the traditional view to manage all silent corticotroph adenomas with adjuvant radiation should be reconsidered. We suggest adopting an initially more conservative follow-up surveillance and delay of upfront radiation until there is clear evidence of tumor recurrence.

The dynamics of post-operative plasma ACTH values following transsphenoidal surgery for Cushing's disease

Rapid assessment of adrenal function is critical following transsphenoidal surgery (TSS) for Cushing's disease (CD) in order to determine surgical efficacy. We hypothesize that there may be a role for ACTH measurement as a rapid indicator of adrenal function. Following surgery for CD, glucocorticoids were withheld and paired plasma ACTH and serum cortisol levels were measured every 6 h. Post-operative hypocortisolemia was defined as serum cortisol <2 mcg/dl or a serum cortisol <5 mcg/dl with the onset of symptoms of adrenal insufficiency within 72 h. We studied 12 subjects, all female, mean age 44.6 years (range 25-55), including 13 surgeries: nine subjects attained hypocortisolemia. Plasma ACTH levels decreased more in subjects with hypocortisolemia (0.9 pg/ml/hr, P = 0.0028) versus those with persistent disease (0 0.2 pg/ml/hr, P = 0.26) within the first 48 h after surgery. In contrast to subjects with persistent disease, all subjects with hypocortisolemia achieved a plasma ACTH <20 pg/ml by 19 h (range 1-19 h). Four of the nine subjects with hypocortisolemia achieved plasma ACTH <20 pg/ml by 13 h and the remaining five subjects by 19 h. Hypocortisolemia occurred between 3-36 h following achievement of a plasma ACTH <20 pg/ml. In CD, a reduction in postoperative plasma ACTH levels differentiates subjects with surgical remission versus subjects with persistent disease. The utility of plasma ACTH measurements in the postoperative management of CD remains to be determined.

Cushing disease as possible cause of persistent growth failure despite growth hormone therapy in a small for gestational age male

Growth hormone (GH) therapy in children with small for gestational age (SGA) has been shown to be of significant therapeutic benefit. We report the case of an 11-year-old Caucasian male who developed early adrenarche, hypertension and insulin resistance on GH therapy for SGA and profound short stature (ht -5 SD). This patient demonstrated a poor response to GH therapy and developed physical and biochemical findings of insulin resistance responsive to metformin therapy. He remained hypertensive, however, and continued to have elevated serum dehydroepiandrosterone sulfate levels. Urinary free cortisol excretion was subsequently found to be elevated. The diagnosis of Cushing's disease was confirmed with inferior petrosal sinus sampling and pituitary MRI. The patient underwent partial adenohypophysectomy with resulting normalization of plasma cortisol levels and associated symptoms. Our patient's diagnosis of Cushing's disease was complicated by his past history of poor growth since birth and history of SGA. The signs of Cushing's disease did not overtly appear until GH therapy was initiated to help treat severe short stature. It is possible that the metabolic effects of GH therapy unmasked the presence of underlying Cushing's disease.

Successful outcome of pregnancy in a patient with Cushing's disease under treatment with ketoconazole during the first trimester of gestation

BACKGROUND

Ketoconazole is the most widely used medical treatment for Cushing's syndrome, but, because of its potential to cause birth defects, it is not recommended during pregnancy. Specifically, due to its antiandrogenic effects, ketoconazole entails theoretical risks of interfering with the development of external genitalia in male fetuses.

CASE

A pregnancy was diagnosed at 13 weeks of gestation in a 26-year-old woman with Cushing's disease under treatment with ketoconazole. The drug was withdrawn and the patient underwent transsphenoidal surgery at 16 weeks of pregnancy. She did not develop postsurgical adrenal insufficiency and was treated with metyrapone during the second and third trimesters of gestation. Partum was induced at 34 weeks of pregnancy. The patient delivered a healthy male infant with normal external genitalia.

CONCLUSION

Treatment with ketoconazole during the critical period of organogenesis did not cause congenital birth defects to the male fetus of a woman with Cushing's disease. This report should be taken into account for future cases of unplanned pregnancies in women with Cushing's syndrome treated with ketoconazole, as well in those cases in which other therapeutic options are not feasible.

Pregnancy does not accelerate corticotroph tumor progression in Nelson's syndrome

CONTEXT

Pituitary surgery is the first line of treatment for Cushing's disease; when surgery fails, bilateral adrenalectomy may be proposed, particularly for women with a desire for pregnancy. Little is known about the impact of pregnancy on corticotroph tumor progression after bilateral adrenalectomy.

OBJECTIVE

The aim was to evaluate the impact of pregnancy on corticotroph tumor progression after bilateral adrenalectomy in Cushing's disease and to assess maternal and pregnancy outcomes.

DESIGN

We conducted a retrospective cohort study.

SETTING

Patients who became pregnant after bilateral adrenalectomy were followed in a single center.

PATIENTS

Twenty pregnancies from 11 patients with Cushing's disease were treated by bilateral adrenalectomy and no pituitary irradiation.

MEASUREMENTS

Corticotroph tumor progression was assessed by serial pituitary magnetic resonance imaging and plasma ACTH measurements before, during, and after pregnancy. Comparisons were performed using paired Wilcoxon rank tests. Data on maternal and neonatal outcomes were recorded by correspondence from patients and obstetricians.

RESULTS

Corticotroph tumor progression occurred in eight of 17 pregnancies, and ACTH increased in eight of 10 pregnancies. However, rates of increase during or after pregnancy were not faster than those observed before pregnancy. Maternal complications occurred in four pregnancies from two patients, including gestational hypertension in three and gestational diabetes mellitus in three. Among these four pregnancies, three had a favorable outcome, and one led to an in utero death after eclampsia, due to loss to follow-up. No other maternal or fetal complications were reported.

CONCLUSION

Pregnancy does not accelerate corticotroph tumor progression after bilateral adrenalectomy. Pregnancy is manageable, provided the patients can be followed closely.

Low immunohistochemical expression of MGMT in ACTH secreting pituitary tumors of patients with Nelson syndrome

MGMT expression in tumors has been correlated with response to treatment with temozolomide therapy. Few medical therapies are available for Nelson syndrome, and the efficacy of such therapeutics remains limited. The aim of the present study was to assess immunohistochemical expression of MGMT in ACTH-secreting pituitary adenomas of patients with Nelson syndrome. Our material consisted of eight specimens from ACTH-secreting pituitary adenomas of patients with Nelson syndrome. Immunohistochemical staining for MGMT was performed using the streptavidin-biotin-peroxidase complex method. MGMT immunoreactivity was assessed microscopically and recorded as an estimated percentage of nuclear MGMT immunostaining (0 = none, 1=<10%, 2=<25%, 3=<50%, 4=>50%). Five of the eight specimens (65%) exhibited no MGMT immunoreactivity, with two out of eight cases (25%) showing slight MGMT staining (<10%) and one out of eight cases (12%) demonstrating moderate MGMT positivity (<25%). Patient male/female ratio was 3:5, with average patient age being 62.4 (range 57–66). Our findings suggest that temozolomide therapy may be of potential use in patients with Nelson syndrome, as these tumors express absent/low levels of MGMT. Absent or low MGMT staining in brain and other neoplasms has been shown to correlate with successful treatment with temozolomide, and recent reports of aggressive pituitary adenomas suggest similar outcomes.

Diagnostic characteristics of late-night salivary cortisol using liquid chromatography-tandem mass spectrometry

OBJECTIVE

The objective of the study was to describe the diagnostic performance of a commercially available late-night salivary cortisol (NSC) assay using liquid chromatography tandem mass spectrometry.

METHODS

We retrospectively identified 90 patients who had one or more NSC determinations: 52 patients in whom Cushing syndrome (CS) was excluded or could not be confirmed [group 1 (G1)] and 38 patients in whom CS was confirmed [group 2 (G2)]. Eighteen healthy volunteers served as controls.

RESULTS

Baseline demographics in all groups were similar with regards to age, ethnicity, gender, and body mass index. NSC levels [median (range)] were higher in G2, 381 (64-13,500) ng/dl [10.51 (1.77-372.46) nmol/liter], compared with controls, 19.3 (2.1-416) ng/dl [0.53 (0.06-11.48) nmol/liter], and G1, 26 (4-176) ng/dl [0.72 (0.11-4.86) nmol/liter, P < 0.001]. The highest combined sensitivity (92%) and specificity (92%) was achieved at a cut point of 107 ng/dl (2.95 nmol/liter). Two or more NSCs were done in 32 of 52 G1 and 31 of 38 G2 patients. In G1 eight of 32 (25%) had at least one elevated [>100 ng/dl (2.76 nmol/liter)] NSC including two in whom both NSCs were elevated. In contrast, four of 31 (13%) in G2 had at least one normal NSC including one with four of five normal NSC values. None of the patients with CS had a NSC less than 60 ng/dl (<1.66 nmol/liter). Comparing G1 and G2, obtaining more than one saliva sample did not improve the diagnostic accuracy of NSC measurement (P = 0.64).

CONCLUSION

The liquid chromatography tandem mass spectrometry assay to measure NSC is a simple and reliable test to screen patients suspected to have CS. Clinicians should be aware of appropriate cutoff values for proper interpretation of NSC and use additional tests when necessary.