Elevated post-dexamethasone suppression cortisol concentrations correlate with hormonal alterations of the hypothalamo-pituitary adrenal axis in patients with adrenal incidentalomas

Thyroid function spectrum in Cushing's syndrome

PURPOSE

Thyroid disorders have been reported in hypercortisolism patients. Endogenous Cushing's syndrome (CS) potentially complicates its metabolic sequelae. We investigated thyroid function in CS patients to determine this relationship.

METHODS

In this cross-sectional study, we screened CS patients from 2016 to 2019 at our hospital. Patient demographic, medical history, and laboratory data were collected. Additionally, we performed a meta-analysis to demonstrate the prevalence of thyroid dysfunction in patients with CS.

RESULTS

Among 129 CS patients, 48.6% had triiodothyronine (TT3), 27.9% had thyroxine (TT4), 24.6% had free T3 (FT3), 27.7% had free T4 (FT4), and 6.2% had thyroid-stimulating hormone (TSH) levels below the reference values. Those with clinical CS showed more pronounced thyroid suppression than did those with subclinical CS. Cortisol levels were markedly greater in patients with pituitary hypothyroidism (P < 0.001). Serum cortisol levels throughout the day and post low-dose dexamethasone-suppression test (LDDST) results correlated with thyroid hormone levels, particularly in ACTH-independent CS. Correlations varied by thyroid status; FT3 and TSH were linked to cortisol in euthyroid individuals but not in those with low T3 or central hypothyroidism. TSH levels notably halved from the lowest to highest cortisol tertile post-LDDST. Finally, meta-analysis showed 22.7% (95% CI 12.6%-32.9%) central hypothyroidism in 528 CS patients of nine studies.

CONCLUSION

Thyroid hormone levels are significantly correlated with cortisol levels and are impaired in patients with CS. However, the physiological adaptation and pathological conditions need further study.

Plasma steroid profiling combined with machine learning for the differential diagnosis in mild autonomous cortisol secretion from nonfunctioning adenoma in patients with adrenal incidentalomas

BACKGROUND

To assess the diagnostic value of combining plasma steroid profiling with machine learning (ML) in differentiating between mild autonomous cortisol secretion (MACS) and nonfunctioning adenoma (NFA) in patients with adrenal incidentalomas.

METHODS

The plasma steroid profiles data in the laboratory information system were screened from January 2021 to December 2023. EXtreme Gradient Boosting (XGBoost) was applied to establish diagnostic models using plasma 24-steroid panels and/or clinical characteristics of the subjects. The SHapley Additive exPlanation (SHAP) method was used for explaining the model.

RESULTS

76 patients with MACS and 86 patients with NFA were included in the development and internal validation cohort while the external validation cohort consisted of 27 MACS and 21 NFA cases. Among five ML models evaluated, XGBoost demonstrated superior performance with an AUC of 0.77 using 24 steroid hormones. The SHAP method identified five steroids that exhibited optimal performance in distinguishing MACS from NFA, namely dehydroepiandrosterone (DHEA), 11-deoxycortisol, 11β-hydroxytestosterone, testosterone, and dehydroepiandrosteronesulfate (DHEAS). Upon incorporating clinical features into the model, the AUC increased to 0.88, with a sensitivity of 0.77 and specificity of 0.82. Furthermore, the results obtained through SHAP revealed that lower levels of testosterone, DHEA, LDL-c, BMI, and ACTH along with higher level of 11-deoxycortisol significantly contributed to the identification of MACS in the model.

CONCLUSIONS

We have elucidated the utilization of ML-based steroid profiling to discriminate between MACS and NFA in patients with adrenal incidentalomas. This approach holds promise for distinguishing these two entities through a single blood collection.

Distinct serum steroid profiles between adrenal Cushing syndrome and Cushing disease

Background

Differentiating between adrenal Cushing syndrome (adrenal CS) and Cushing disease (CD) can be challenging if there are equivocal or falsely elevated adrenocorticotropic hormone (ACTH) values. We aim to investigate the diagnostic value of serum steroid profiles in differentiating adrenal CS from CD.

Method

A total of 11 serum steroids in adrenal CS (n = 13) and CD (n = 15) were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Age- and gender-specific steroid ratios were generated by dividing the actual steroid concentration by the upper limit of the relevant reference range. A principal component analysis (PCA) and an orthogonal partial least squares discriminant analysis (OPLS-DA) were performed.

Results

The PCA and OPLS-DA analyses showed distinct serum steroid profiles between adrenal CS and CD. Dehydroepiandrosterone sulfate (DHEA-S), dehydroepiandrosterone (DHEA), and androstenedione ratios were identified as biomarkers for discrimination by variable importance in projection (VIP) in combination with t-tests. The sensitivity and specificity of DHEA-S ratios <0.40 were 92.31% (95% CI 64.0%-99.8%) and 93.33% (95% CI 68.1%-99.8%), respectively, in identifying adrenal CS. The sensitivity and specificity of DHEA ratios <0.18 were 100% (95% CI 75.3%-100.0%) and 100% (95% CI 78.2%-100.0%), respectively, in identifying adrenal CS.

Conclusion

Our data support the clinical use of the DHEA-S and DHEA ratios in the differential diagnosis of adrenal CS and CD, especially when falsely elevated ACTH is suspected.

Cardiovascular complications of mild autonomous cortisol secretion

Adrenal incidentalomas (AI) may be associated with a mild autonomous cortisol secretion (MACS) in up to one third of cases. There is growing evidence that MACS patients actually present increased risk of cardiovascular disease and higher mortality rate, driven by increased prevalence of known cardiovascular risk factors, as well as accelerated cardiovascular remodelling. Adrenalectomy seems to have cardiometabolic beneficial effects in MACS patients but their management is still a debated topic due to the lack of high-quality studies. Several studies suggested that so called "non-functioning" AI may be actually "functioning" with an associated increased cardiovascular risk. Although the individual cortisol sensitivity and peripheral activation have been recently suggested to play a role in influencing the cardiovascular risk even in apparently eucortisolemic patients, to date the degree of cortisol secretion, as mirrored by the cortisol levels after dexamethasone suppression test remains the best predictor of an increased cardiovascular risk in AI patients. However, whether or not the currently used cut-off set at 50 nmol/L for cortisol levels after dexamethasone suppression could be considered completely reliable in ruling out hypercortisolism remains unclear.

Serum Cortisol Levels via Radioimmunoassay vs Liquid Chromatography Mass Spectrophotometry in Healthy Control Subjects and Patients With Adrenal Incidentalomas

Background

Adrenal incidentalomas (AIs) are present in 4% of adults. As many as 30% may secrete cortisol autonomously in the absence of specific signs of overt hypercortisolism, in a phenomenon called subclinical hypercortisolism (SH). Diagnosis of SH is established by serum cortisol resistance to dexamethasone suppression.

Methods

We compared serum cortisol concentrations, as determined by radioimmunoassay (RIA) and liquid chromatography/tandem mass spectronomy (LC/MS-MS), in 73 patients with AI group (52 with unilateral AI) and 34 control subjects in 3 scenarios: basal; after 1-mg dexamethasone suppression; and after 0.25-mg stimulation with cosyntropin, a synthetic derivative of adrenocorticotropic hormone (ACTH). To bolster evidence for the diagnosis of SH, we also measured salivary cortisol levels at 11 PM and after DST, as well as plasma ACTH and serum dehydroepiandrosterone sulfate (DHEA-S) levels.

Results

We observed significant positive correlation (r = 0.9345, P <.001) for all 318 pairs of serum cortisol values, as measured by both methods.

Conclusions

Serum cortisol concentrations in patients with AI and in control subjects were very similar, as measured by RIA and LC/MS-MS.

Cortisol: Mediator of association between Alzheimer's disease and diabetes mellitus?

Numerous epidemiologic studies have identified an independent association between Alzheimer's disease (AD) and diabetes mellitus (DM), which remains unexplained. This review contends that the association is mediated by mild hypercortisolemia that is manifested in AD by early stages, as empirical evidence indicates that hypercortisolemia is diabetogenic even at subclinical levels. Subclinical Cushing's syndrome is discussed as the paradigm. It is proposed that hypercortisolemia increases the risk of pre-diabetes and DM during early AD and the preceding decades. That hypercortisolemia is exhibited during the AD prodromal stage has yet to be determined, but may be inferred from concurrent metabolic parameters as documented in the literature. Studies refuting association between AD and DM also are evaluated, and the relationship between AD and DM is deduced to be more complex than directly causal, with DM of longstanding duration having a protective role. Association between DM and AD may require reappraisal by APOE ε4 carrier status, in view of newly identified roles of APOE ε4 in pre-diabetes. That association of APOE ε4 with DM in AD may have been underestimated in epidemiologic studies also is highlighted. At the core of arguments and mechanisms presented in this review is the circadian rhythm of cortisol secretion, which is the main determinant of glycemic control in humans. Alterations to that rhythm and to the hypothalamic-pituitary-adrenal axis occurring in AD are examined. Consequently the cause of hypercortisolemia in AD, and therefore of association between AD and DM, is proposed to be adrenal hyper-responsiveness to adrenocorticotropic hormone.

DHEAS for the prediction of subclinical Cushing's syndrome: perplexing or advantageous?

The diagnostic accuracy of dehydroepiandrosterone sulfate (DHEAS) to predict subclinical Cushing's syndrome (sCS) has been a matter of debate. The primary objective of this study was to assess the diagnostic power of DHEAS in predicting sCS. This retrospective study was conducted in a tertiary referral center and based on subjects referred between 2004 and 2014. Data of 249 subjects with adrenal incidentalomas were evaluated. We also reviewed 604 DHEAS measurements from adults, which were performed during the same period in our laboratory (LB group). Adrenocortical function, tumor size, and clinical characteristics were assessed. We diagnosed sCS in 15.2 % of the participants in the presence of ≥2 of the following; 1 mg dexamethasone suppression test >3.0 μg/dl, urinary free cortisol >70 μg/24 h, and corticotrophin (ACTH) <10 pg/ml. DHEAS levels were significantly reduced in patients with sCS (n = 38) compared to sCS (-) (n = 141) and LB groups (n = 604) (27.95, 65.90, and 66.80 µg/dl, respectively, p < 0.001) while age was comparable. The ROC curve analysis showed that the cut-off of the DHEAS with the best diagnostic accuracy for detecting sCS was 40.0 μg/dl (SN, 68 %; SP, 75; PPV, 43 %; NPV, 90 %, AUC: 0.788, p < 0.001). Logistic regression assessed the impact of age, BMI, low DHEAS (<40 μg/dl), bilateral tumors, and tumor size on the likelihood of having sCS. The strongest predictor was low DHEAS, recording an OR of 9.41. DHEAS levels are inversely associated with the extent of cortisol excess. In subjects with intermediate laboratory findings, detection of low DHEAS could be advantageous for distinguishing sCS.

Mifepristone reduces insulin resistance in patient volunteers with adrenal incidentalomas that secrete low levels of cortisol: a pilot study

Background

Incidental adrenal masses are commonly detected during imaging for other pathologies. 10% of the elderly population has an ‘adrenal incidentaloma’, up to 20% of these show low-grade autonomous cortisol secretion and 60% of patients with autonomous cortisol secretion have insulin resistance. Cortisol excess is known to cause insulin resistance, an independent cardiovascular risk marker, however in patients with adrenal incidentalomas it is unknown whether their insulin resistance is secondary to the excess cortisol and therefore potentially reversible. In a proof of concept study we examined the short-term effects of glucocorticoid receptor (GR) antagonism in patients with an adrenal incidentaloma to determine whether their insulin resistance was reversible.

Methodology/Principal Findings

In a prospective open-label pilot study, six individuals with adrenal incidentalomas and autonomous cortisol secretion were treated with mifepristone (a GR antagonist) 200 mg twice daily and studied for 4 weeks on a Clinical Research Facility. Insulin resistance at four weeks was assessed by insulin resistance indices, lnHOMA-IR and lnMatsuda, and AUC insulin during a 2-hour glucose tolerance test. Biochemical evidence of GR blockade was shown in all individuals and across the group there was a significant reduction in insulin resistance: lnHOMA-IR (1.0vs0.6; p = 0.03), lnHOMA-%beta (4.8vs4.3; p = 0.03) and lnMatsuda (1.2vs1.6; p = 0.03). Five out of six individuals showed a reduction in insulin AUC >7237 pmol/l.min, and in two patients this showed a clinically significant cardiovascular benefit (as defined by the Helsinki heart study).

Conclusions

Short-term GR antagonism is sufficient to reduce insulin resistance in some individuals with adrenal incidentalomas and mild cortisol excess. Further assessment is required to assess if the responses may be used to stratify therapy as adrenal incidentalomas may be a common remediable cause of increased cardiovascular risk.

Trial Registration

ClinicalTrials.gov NCT00721201

Current status and controversies in adrenal incidentalomas

Adrenal incidentalomas (AI) are serendipitously discovered lesions during abdominal imaging studies that need to be investigated for evidence of hormonal hypersecretion and/or malignancy. Because imaging modalities can reliably identify lesions that carry a high risk of malignancy, we focus on the identification of hypersecretory lesions and those with subclinical activity, particularly Cushing syndrome. Because diverse diagnostic tests and cut-offs are employed, the prevalence of hypersecretory AI varies widely, and there is controversy regarding their long-term sequelae. In this article we provide information regarding current radiological means to define the nature of AI, and the most appropriate biochemical tests for delineating hypersecretory states. We also discuss the duration and intensity of AI follow-up as well as the identification of AI that require specific therapeutic intervention.

Subclinical Cushing's syndrome

The routine use of abdominal procedure has significantly increased the incidental finding of adrenal masses. The prevalence of these tumors, commonly defined as adrenal incidentalomas, ranges between 2-3% in autopsy and 4% in radiological series, reaching 5-8% in oncological studies and increasing with patients age. Although clinically silent, in 5-20% of cases, adrenal incidentalomas are responsible for a subtle cortisol overproduction, commonly defined as "subclinical Cushing's syndrome" (SCS). This term is used to describe autonomous cortisol secretion in patients who don't have the typical signs and symptoms of hypercortisolism. The optimal strategy for identification and management of SCS is unknown; the standard biochemical tests used to screen for overt Cushing's syndrome are generally ill-suited to the assessment of patients who have no, or only very mild signs of cortisol excess, then many tests aimed to study the hypothalamus-pituitary-adrenal axis (HPA) axis do not have sufficient sensitivity to recognize very mild degree of cortisol excess. An increased frequency of hypertension, central obesity, impaired glucose tolerance or diabetes, hyperlipemia and osteoporosis has been described in patients with SCS since patients are exposed to a chronic albeit slight, cortisol excess; however, there is not evidence-based demonstration of long term complications and, consequently, the management of this condition is largely empirical. Adrenalectomy or medical management of associated disease has been indicated as therapeutic options due to lack of data demonstrating the superiority of a surgical or non-surgical treatment.

Subclinical hypercortisolism and CT appearance in adrenal incidentalomas: a multicenter study from Southern Sweden

Evaluation of subclinical hypercortisolism (SH) in patients with adrenal incidentaloma (AI) including its correlation to size, attenuation at unenhanced computed tomography (CT) and unilateral or bilateral adrenal disease. Nine hospitals in Southern Sweden investigated during 2005-2007 consecutively patients with AI with hormonal and CT examinations according a regional protocol. Two hundred and twenty-eight patients with AI with median size 2.0 cm were included. One mg overnight dexamethasone suppression test (DST) was performed in 223 patients and basal P-ACTH measured in 146 patients. SH was defined as cortisol ≥ 50 nmol/l at DST in combination with basal ACTH <2 pmol/l. In patients with unilateral AI 42% (76/180) had inadequate suppression at DST and 23% (27/115) had SH. The probability for SH and inadequate suppression at DST correlated positively to size and inversely to attenuation at CT. Bilateral AI were found in 43 patients and of these 70% (30/43) had inadequate suppression at DST and 42% (13/31) SH. The patients with SH or inadequate suppression at DST had increased frequency of hypertension which increased further in patients with post-DST cortisol ≥ 140 nmol/l. The applied criterion for SH is useful for initial evaluation of patients with AI. SH is common in patients with AI, particular in bilateral disease. In patients with unilateral AI the probability for SH correlated positively to size and inversely to attenuation at CT. Furthermore, SH and the post-DST cortisol concentration was associated with hypertension.

Clinical and biochemical impact of BCL1 polymorphic genotype of the glucocorticoid receptor gene in patients with adrenal incidentalomas

BACKGROUND

Adrenal incidentaloma (AI) is a common clinical problem. Subtle hormonal abnormalities are present in a substantial proportion of patients. BCL1 gene polymorphism of the glucocorticoid receptor (GR) is associated with increased sensitivity to glucocorticoid action. The genotype- phenotype associations of this polymomorphism in patients presenting with AI has not been extensively investigated.

AIM

A cross-sectional study in secondary/tertiary care centers.

SUBJECTS/METHODS

Ninety-five subjects with AI were genotyped for the BCL1 GR gene polymorphism. Patients underwent an oral glucose tolerance test and a dexamethasone suppression test (DST). The presence of subclinical hypercortisolism, features of metabolic syndrome, and osteoporosis/ osteopenia were also assessed.

RESULTS

No significant differences in markers of adrenal function between BCL1 carriers and non-carriers were revealed. Also, no difference was found in the features of metabolic syndrome, as well as in bone metabolism and density between these 2 groups. However, DST suppressor patients belonged more frequently to the BCL1 carriers group (41 out of 69 patients, 59.4% vs 9 out of 26 patients, 34.6%, p=0.0039), had smaller total adenoma size (2.4±0.2 cm vs 3.5±0.4 cm, p=0.04), and lower incidence of bilateral adrenal masses (18.8% vs 46.2%, p=0.01).

CONCLUSIONS

AI patients who also carry the polymorphic BCL1 variant exhibit smaller size adrenal nodules. Those AI patients with complete DST suppression had a higher incidence of the polymorphic BCL1 variant. However, this study failed to demonstrate any significant impact of BCL1 GR polymorphism on the frequency of cortisol-dependent co-morbidities in patients with AI.

Hormonal activity in clinically silent adrenal incidentalomas

INTRODUCTION

The rapid development of modern imaging techniques, has led to an increase in accidentally discovered adrenal masses without clinically apparent hormonal abnormalities. Such tumours have been termed "incidentalomas". The diagnostic work-up in patients with adrenal incidentalomas is aimed at the determination of hormonal activity of the tumour and identification of patients with potentially malignant tumours. The aim of our study was a retrospective analysis of selected clinical characteristics and hormonal studies in accidentally discovered adrenal tumours.

MATERIAL AND METHODS

Fourty hundred sixty-three patients with serendipitously discovered adrenal masses, diagnosed and treated in the Department of Endocrinology and Internal Diseases, Medical University of Gdansk as well as in the affiliated Endocrinology Clinic between 1993 and October of 2009 were included in the analysis. Out of all patients, 245 were referred for adrenalectomy.

RESULTS

We found that clinically "silent" tumours often demonstrate subclinical hormonal activity. In our report, increased 24-h urinary excretion of cortisol correlated positively with tumour size (p < 0.001). Moreover, a statistical relationship was demonstrated between tumour size and serum cortisol concentration assessed in the 1 mg dexamethasone suppression test (p < 0.001). Increased values of dehydroepiandrosterone/dehydroepiandrosterone sulphate were more often found in malignant than in benign tumours (p < 0.01). Urinary concentrations of 17-ketosteroids correlate positively with diagnosis of adrenocortical cancer (p = 0.02).

CONCLUSIONS

We found that clinically "silent" tumours often demonstrate subclinical hormonal activity (subclinical Cushing syndrome, subclinical pheochromocytoma, low-symptomatic adrenocortical cancer).

Subclinical Cushing's syndrome: definition and management

Subclinical Cushing's syndrome is an ill-defined endocrine disorder that may be observed in patients bearing an incidentally found adrenal adenoma. The concept of subclinical Cushing's syndrome stands on the presence of ACTH-independent cortisol secretion by an adrenal adenoma, that is not fully restrained by pituitary feed-back. A hypercortisolemic state of usually minimal intensity may ensue and eventually cause harm to the patients in terms of metabolic and vascular diseases, and bone fractures. However, the natural history of subclinical Cushing's syndrome remains largely unknown. The present review illustrates the currently used methods to ascertain the presence of subclinical Cushing's syndrome and the surrounding controversy. The management of subclinical Cushing's syndrome, that remains a highly debated issue, is also addressed and discussed. Most of the recommendations made in this chapter reflects the view and the clinical experience of the Authors and are not based on solid evidence.

Aberrant cortisol responses to physiological stimuli in patients presenting with bilateral adrenal incidentalomas

Aberrant receptors have been implicated in the pathogenesis of several types of adrenal tumours. So far the presence of aberrant receptors has been investigated in patients with massively enlarged adrenals due to ACTH-independent macronodular adrenal hyperplasia (AIMAH) and unilateral adrenal adenomas associated with overt or subclinical Cushing's syndrome. The likelihood of aberrant responses in patients presenting with bilateral adrenal incidentalomas (BI) presenting as discrete solitary bilateral adenomas has not been thoroughly addressed. This is an observational cross-sectional prospective study conducted in a secondary/tertiary care centre. We studied 33 patients; 28 with incidentally discovered bilateral discrete adrenal adenomas and five with massive bilateral adrenal macronodular hyperplasia. We probed responses to physiological stimuli, namely upright posture and meal; in a subgroup of menopausal women the presence of aberrant gonadotropin receptors was assessed by the LHRH test. Abnormal responses obtained in tests performed with no dexamethasone suppression were always repeated and confirmed under dexamethasone suppression. Aberrant cortisol responses were confirmed in 10 patients; 9 to posture, 1 to meal (along with a positive response to posture) and 1 to LHRH tests. Patients who responded to any test compared to those who tested negative had larger adenomas, higher post-LDDST and midnight cortisol and a trend for lower ACTH levels. Patients without subclinical hypercortisolism (SH) did not respond to any test while 50% of patients with SH had an aberrant response (P = 0.002). A greater prevalence of aberrant responses was noted in patients with bilateral macronodular hyperplasia compared to those with solitary bilateral adenomas (80 vs. 21.4%, P = 0.02). Aberrant cortisol responses, primarily to posture testing, are present in a substantial proportion of patients with bilateral adrenal incidentalomas. Such cortisol responses are observed only in patients with subclinical hypercortisolism and especially in those patients with larger adrenal lesions.

Endocrine incidentalomas--challenges imposed by incidentally discovered lesions

Endocrine glands are among the organs that most frequently harbor incidentally discovered lesions. Pituitary, thyroid, parathyroid and adrenal incidentalomas are increasingly encountered in everyday practice with variable clinical implications. The major concerns are the risks of malignancy and hormonal hypersecretion mostly in the form of subclinically functioning tumors. Pituitary incidentalomas are usually microadenomas and most of the time clinically unimportant; however, incidentally discovered larger lesions require a more careful diagnostic and therapeutic approach. Thyroid incidentalomas are extremely common; exclusion of malignancy is the main concern in this clinical setting. Although parathyroid adenomas are not uncommon, these lesions are frequently missed owing to their small size and due to clinical unawareness. Adrenal incidentalomas carry a small but finite risk of malignancy. An intriguing challenge regarding incidentally discovered adrenal lesions is that a substantial proportion is associated with hormonal alterations, mainly in the form of subtle cortisol excess. Although still largely controversial, evidence is emerging that so-called subclinical hypercortisolism may not be completely harmless. The best biochemical criterion of subtle cortisol excess remains elusive. Surgical intervention in selected cases results in some beneficial effects, but more data are required in order to routinely support surgery in this clinical setting. This Review provides a brief overview of the prevalence, clinical effect and management of endocrine incidentalomas with a focus on data regarding the diagnostic and therapeutic challenges imposed by incidentally discovered adrenal lesions.

Clinical review: Diagnosis and treatment of subclinical hypercortisolism

CONTEXT

Subclinical hypercortisolism (SH) is a condition of biochemical cortisol excess without the classical signs or symptoms of overt hypercortisolism. It is thought to be present in the 5-30% of patients with incidentally discovered adrenal mass (adrenal incidentalomas), which in turn are found in 4-7% of the adult population. Therefore, SH has been suggested to be present in 0.2-2.0% of the adult population. Some studies suggested that this condition is present in 1-10% of patients with diabetes or established osteoporosis. The present manuscript reviews the literature on diagnostic procedures and the metabolic effect of the recovery from SH.

EVIDENCE ACQUISITION

A PubMed search was used to identify the available studies. The most relevant studies from 1992 to November 2010 have been included in the review.

EVIDENCE SYNTHESIS

The available data suggest that SH may be associated with chronic complications, such as hypertension, diabetes mellitus, overweight/obesity, and osteoporosis. The available intervention studies suggest that the recovery from SH may lead to the improvement of hypertension and diabetes mellitus. A retrospective study suggests that this beneficial effect could be predicted before surgery.

CONCLUSIONS

SH is suggested to be associated with some chronic complications of overt cortisol excess. Recovery from this condition seems to improve these complications. However, a large, prospective, randomized study is needed to confirm this hypothesis and to establish the best diagnostic approach to identify patients with adrenal incidentalomas who can benefit from surgery.

High prevalence of subclinical hypercortisolism in patients with bilateral adrenal incidentalomas: a challenge to management

OBJECTIVE

The prevalence of subclinical hypercortisolism (SH) in unilateral incidentalomas (UI) has been extensively studied; however, patients with bilateral incidentalomas (BI) have not been thoroughly investigated. We therefore aimed to describe the characteristics of patients with BI compared to their unilateral counterparts. The surgical outcome in a small number of patients is reported.

DESIGN

Observational retrospective study in a single secondary/tertiary centre.

PATIENTS

One hundred and seventy-two patients with adrenal incidentalomas (41 with BI).

MEASUREMENTS

Morning cortisol (F), ACTH, dehydroepiandrosterone sulphate (DHEA-S), midnight F, 24-h urine collection for cortisol (UFC), low-dose dexamethasone suppression test (LDDST), fasting glucose, insulin, and oral glucose tolerance test (OGTT). Primarily, SH was defined as F-post-LDDST>70 nmol/l and one more abnormality; several diverse cut-offs were also examined.

RESULTS

No difference was noted in age, body mass index, or prevalence of diabetes and impaired glucose tolerance between patients with UI and those with BI. Patients with BI had higher F-post-LDDST (119·3 ± 112·8 vs 54·3 ± 71·5 nmol/l, P<0·001) and lower DHEA-S (1·6 ± 1·5 vs 2·5 ± 2·3 μmol/l, P=0·003) but similar UFC, ACTH and midnight F levels, compared to UI. SH was significantly more prevalent in BI (41·5%vs 12·2%, P<0·001). Fourteen patients were operated on; four underwent bilateral interventions. In 10 patients, unilateral adrenalectomy on the side of the largest lesion resulted in significant improvement in F-post-LDDST (P=0·008) and a decrease in midnight F (P=0·015) levels.

CONCLUSIONS

Subclinical hypercortisolism is significantly more prevalent in bilateral incidentaloma patients, posing great dilemmas for its optimum management.

Hormonal activity of adrenal incidentalomas: results from a long-term follow-up study

OBJECTIVE

To investigate the natural course of apparently benign adrenal incidentalomas with no overt hyperfunction at diagnosis, as their clinical significance and appropriate management are still controversial.

DESIGN

Prospective long-term follow-up study of patients with adrenal incidentalomas with periodic hormonal and morphological evaluation.

PATIENTS AND METHODS

A total of 77 patients with incidental adrenal masses, diameter 1.0-6.0 cm (median 2.5 cm), were submitted to a hormonal assessment of adrenal function at diagnosis. This was repeated, together with an adrenal CT scan, 12 months later and then every 12-24 months, for a period of 12-154 months (mean 62.7 +/- 31.9, median 60.0).

RESULTS

At diagnosis, 57 patients had normal adrenal function and 20 had subclinical Cushing's syndrome. During follow-up, adrenal function remained normal in 49 patients, subclinical Cushing's syndrome was confirmed in 12, whilst intermittent subclinical autonomous cortisol hypersecretion was found in 12 patients. Overt endocrine disease was diagnosed in 4 patients (Cushing's syndrome in 2 and phaeochromocytoma in 2). A change in mass size (> or = 0.5 cm) was observed in 26 patients (enlargement in 20--including patients who developed overt hyperfunction--with no signs of malignancy and reduction in size in 6).

CONCLUSIONS

Subclinical autonomous cortisol hypersecretion is the most frequent hormonal abnormality in patients with adrenal incidentalomas, and may be intermittent in a significant percentage of cases. Few patients develop overt endocrine disease. A growth tendency is observed in some adrenal incidentalomas without evidence of malignant transformation and occasionally can be related to development of overt hyperfunction. These findings indicate the need for periodic hormonal and morphological evaluation for several years.

Hyper-responsiveness of adrenal gland to vasopressin resulting in enhanced plasma cortisol in patients with adrenal nodule(s)

Hyper-responsiveness of plasma cortisol to vasopressin has been demonstrated in ACTH-independent bilateral macronodular adrenocortical hyperplasia (AIMAH) and some adrenal adenomas with Cushing's syndrome (CS). However, the clinical significance of hyper-responsiveness of plasma cortisol to vasopressin has not been investigated systematically in adrenal nodule(s). The aim of this study was to clarify the prevalence of hyper-responsiveness of plasma cortisol to vasopressin (vasopressin responder) and their clinical characteristics in terms of hormonal secretion using vasopressin-loading test in the patients with adrenal nodule(s) except pheochromocytomas. A vasopressin-loading test was performed on 61 consecutive patients with adrenal nodules (CS: 33, aldosterone-producing adenoma: 10, non-functional tumor: 18). Vasopressin responders were observed in 36.1% of adrenal nodule(s), 42.4% of CS and 28.5% of non-CS. In responders with CS, eight patients had bilateral nodules that were diagnosed as AIMAH, and the remaining six patients had a unilateral nodule. These patients had lower plasma cortisol than non-responders at both morning (P<0.01) and midnight (P<0.05), as well as the morning following overnight dexamethasone suppression at 1mg (P<0.05) and 8mg (P<0.05). Hyper-responsiveness of the adrenal gland to vasopressin resulting in enhanced plasma cortisol was frequently observed among patients with adrenal nodule(s). The vasopressin responders among the patients with adrenal nodule(s) frequently had CS with low autonomous cortisol secretion.

"Subclinical Cushing's syndrome" is not subclinical: improvement after adrenalectomy in 9 patients

BACKGROUND

A subgroup of patients with adrenal cortisol hypersecretion fails to meet the biochemical criteria for Cushing's syndrome. Appropriate therapy for this entity, subclinical Cushing's syndrome (subclinical CS), is unclear. We examined outcomes for patients who underwent unilateral adrenalectomy for subclinical CS.

METHODS

Between 2003 and 2006, all patients who underwent adrenalectomy for cortisol hypersecretion caused by an adrenal mass were examined. We analyzed biochemical, metabolic, and clinical outcomes.

RESULTS

Overall, 24 patients underwent adrenalectomy for adrenal cortisol hypersecretion, of which 9 were found to have subclinical CS. Median serum cortisol was 2.0 microg/dL (range, 1.1-6.1) after 1-mg overnight dexamethasone suppression testing. Suspicious clinical findings on preoperative examination included skin bruising, unexplained weight gain, proximal muscle weakness, abnormal fat pads, skin thinning, fatigue, and facial plethora. During a median follow-up period of 5 months (range, 1-30 months), all 8 patients with easy bruising noted resolution postoperatively. Fatigue improved in 4 of 5 patients, muscle weakness in 6 of 8 patients, and weight in 7 of 9 patients, with a median body mass index change of -2.0 kg/m(2) (range, -7.1 to +0.5 kg/m(2)).

CONCLUSION

Adrenalectomy improves clinical and metabolic parameters for many patients with subclinical CS.

The aldosterone to renin ratio in the evaluation of patients with incidentally detected adrenal masses

Incidentally discovered adrenal masses are diagnosed with increasing frequency, especially among patients with hypertension. Thus, a reliable screening test for primary hyperaldosteronism (PA) is essential to avoid unnecessary diagnostic procedures to this population. The aim of the present study is the evaluation of aldosterone to renin ratio (ARR), using plasma renin concentration, in the diagnostic algorithm of patients with adrenal incidentaloma. A total of 123 individuals were studied: 17 patients with proven PA (age 55.5 +/- 1.4 years), 27 patients with nonfunctioning adrenal incidentaloma (age 60.3 +/- 1.8 years, 14 hypertensives and 13 normotensives) and 79 control subjects (age 58.7 +/- 1.4 years, 27 hypertensives and 52 normotensives). A receiver operating characteristic (ROC) analysis disclosed that an ARR > or =32 combines a sensitivity of 100% with a specificity of 96.2% for the diagnosis of PA. No difference in AlphaRR between hypertensive and normotensive individuals harbouring an adrenal incidentaloma and hypertensive and normotensive controls was found. Patients with adrenal incidentalomas with subtle glucocorticoid hypersecretion demonstrated similar ARR compared to patients with normal cortisol secretion. In conclusion, ARR is reliable for the exclusion of PA in patients with adrenal incidentalomas. Furthermore, subtle aldosterone hypersecretion, as indicated by increased ARR, in patients with adrenal incidentalomas is not associated with the presence of hypertension or subtle glucocorticoid hypersecretion.

[Adrenal incidentalomas]

Adrenal incidentalomas are clinically inapparent masses detected incidentally with imaging studies conducted for other reasons. They are relatively common and require structured diagnostic workup. In many cases surveillance is warranted. The diagnostic workflow has to reveal whether the mass is hormonally functioning and/or if there is evidence of malignancy. If the tumor is functionally silent and not larger than 4 cm, surveillance is warranted. Functioning tumors and masses larger than 6 cm have to be resected. Fine-needle aspiration biopsy is indicated in very rare cases, but pheochromocytoma has to be ruled out first.

Endogenous subclinical hypercortisolism: Diagnostic uncertainties and clinical implications

Subclinical hypercortisolism (SH) is a newly characterized hormonal disorder that is almost exclusively detected in the context of incidentally discovered adrenal masses. The diagnostic criteria used for the definition of this condition are at present controversial. Amongst the various tests used for the detection of this abnormality (dexamethasone suppression, urinary free cortisol, ACTH levels, midnight serum or salivary cortisol concentrations, ACTH responses to CRH stimulation), the dexamethasone suppression tests (DST) seem to better accomplish the task of unmasking subtle abnormalities of cortisol secretion. Several versions of DST have been used: the 1-mg overnight, the 3-mg overnight and the classical 2-day low-dose DST. This latter test has the theoretical advantage that, by more efficiently suppressing pituitary ACTH secretion, it may provide a measure of the residual (ie non- ACTH-dependent) cortisol secretion from the adrenal mass. In this way, post-dexamethasone cortisol concentrations may quantify the degree of autonomous cortisol hypersecretion. In fact, post-dexamethasone cortisol concentrations have a negative correlation with basal ACTH levels and a positive correlation with midnight cortisol concentrations as well as the size of the incidentally discovered adrenal mass. Most of the existing data indicate that SH detected in the context of adrenal incidentalomas may have some clinically significant implications. In fact, patients with higher post-dexamethasone cortisol concentrations demonstrate higher lipid levels and lower bone mass densities. It has also been suggested that SH may be responsible for biochemical and phenotypic changes reminiscent of the metabolic syndrome. In summary, SH does exist and is associated with a negative impact in patients' health; however, hormonal cut-off criteria for decision-making remain to be defined.

Midnight serum cortisol as a marker of increased cardiovascular risk in patients with a clinically inapparent adrenal adenoma

OBJECTIVE

There is scant information on the morbidity associated with subclinical Cushing's syndrome in patients with a clinically inapparent adrenal adenoma. In the present study, we have determined the prevalence of alterations of the hypothalamic-pituitary-adrenal axis in such patients and examined whether any correlation between endocrine data and the clinical phenotype exists.

DESIGN AND METHODS

A multi-institutional retrospective study was carried out on 210 patients (135 women and 75 men aged 19-81 years) with an adrenal adenoma detected serendipitously between 1996 and 2000 in four referral centers in Italy.

RESULTS

Hypertension was observed in 53.8%, obesity in 21.4% and hyperglycemia in 22.4% of patients. The 47 patients with midnight serum cortisol >5.4 microg/dl, a value corresponding to the 97th centile of 100 controls, were older and displayed greater fasting glucose (120.4+/-52.2 mg/dl vs 105.1+/-39.2 mg/dl, P = 0.04) and systolic blood pressure (148.3+/-14.6 mmHg vs 136.4+/-16.2 mmHg, P = 0.0009) than the 113 patients with normal cortisol levels. The difference in systolic blood pressure remained statistically significant (P = 0.009) when age was used as a covariate. The percentage of hypertensive patients undergoing treatment was not different between the two groups (90.5 and 97.1%) but the percentage of patients with controlled hypertension was significantly lower among the hypercortisolemic patients (12.5 vs 32.4%, P = 0.04). Glycated haemoglobin (HbA1c) levels were higher in the hypercortisolemic diabetic patients (8.9+/-1.1% vs 7.1+/-1.3%, P = 0.005).

CONCLUSIONS

Elevated midnight cortisol concentration is a reliable test to select a subgroup of patients with a clinically inapparent adrenal adenoma with an adverse cardiovascular risk profile.

Subclinical Cushing's syndrome in adrenal incidentalomas

This article reviews the available evidence on subclinical Cushing's syndrome in patients who have adrenal incidentalomas. The authors' aim is to present up-to-date information on the most relevant issues of subclinical Cushing's syndrome by addressing the many uncertainties and controversies surrounding this ill-defined endocrine condition.

Evaluation of GH reserve in patients with adrenal incidentalomas and biochemical evidence of subclinical autonomous glucocorticoid hypersecretion

OBJECTIVE

Although it is well established that overt hypercortisolism in patients with active Cushing's syndrome leads to a profound suppression of stimulated GH secretion, the role of subclinical autonomous glucocorticoid hypersecretion (SAGH), currently detected with increasing frequency in patients with adrenal incidentalomas, on GH secretory reserve has received little attention. The aim of the present study was to evaluate whether SAGH in patients presented with adrenal incidentalomas has a negative effect on GH secretory reserve.

DESIGN AND PATIENTS

Sixteen patients with overt Cushing's syndrome (CS) and 36 patients with adrenal incidentalomas were investigated. The latter group was further divided in 23 patients who demonstrated an adequate suppression of cortisol levels (of < 70 nmol/l) following the low-dose dexamethasone suppression test (LDDST) and in 13 patients, who failed to suppress (cortisol levels post-LDDST > 70 nmol/l). The former group was defined as normocortisolaemic (NC) and the latter group as representing patients with SAGH. The combined pyridostigmine + GHRH test (PD + GHRH) was used to assess the GH secretory reserve of these patients.

RESULTS

Peak GH levels following PD + GHRH administration were significantly lower in CS patients compared to both the NC and SAGH group of patients with adrenal incidentalomas (2.2 +/- 0.7 vs. 18.9 +/- 2.6 and 21.5 +/- 3.6 microg/l, respectively, P < 0.05); no difference was observed in peak GH responses between the NC and SAGH group of patients. A subnormal GH response (defined as GH(max) < 12.8 microg/l) was observed in all 16 patients with CS. However, only seven NC and three SAGH patients failed to respond adequately. Correlation analysis revealed a negative correlation between peak GH response to PD + GHRH and plasma cortisol concentrations in CS patients (R =-0.6, P = 0.012), while in patients with adrenal incidentalomas such a correlation was absent. Contrary to patients with CS in whom body mass index (BMI) was not correlated to peak GH, a significant negative correlation between peak GH response to PD + GHRH and BMI was disclosed in patients with adrenal incidentalomas (R =-0.49, P = 0.003). In these patients, again contrary to CS patients, a significant negative correlation was also found between peak GH post PD + GHRH and age (R = -0.46, P = 0.002).

CONCLUSIONS

In conclusion, our results provide evidence that, contrary to patients with overt CS, SAGH does not affect the GH secretory response to provocative stimulation.

Subclinical Cushing's syndrome in adrenal incidentalomas

Up to 20% of patients with adrenal incidentalomas have abnormal cortisol production, and can be classified as having subclinical Cushing's syndrome. Although these tumors do not secrete enough cortisol to lead to the development of overt Cushing's syndrome, they are likely playing a contributory role in the development of hypertension, diabetes, osteoporosis, and obesity. Studies suggest that many of these problems can be reversed with surgical treatment. Additionally, if this diagnosis is not sought out before pursuing an adrenalectomy for an incidentaloma, the patient can develop profound postoperative adrenal insufficiency.

Subclinical Cushing's syndrome

Clinically inapparent adrenal masses, or adrenal incidentalomas, are discovered inadvertently in the course of workup or treatment of unrelated disorders. Cortical adenoma is the most frequent type of adrenal incidentaloma accounting for approximately 50% of cases in surgical series and even greater shares in medical series. Incidentally discovered adrenal adenomas may secrete cortisol in an autonomous manner, that is not fully restrained by pituitary feed-back, in 5 to 20% of cases depending on study protocols and diagnostic criteria. A number of different alterations in the endocrine tests aimed to assess the function of the hypothalamic-pituitary-adrenal axis has been demonstrated in such patients. This heterogeneous condition has been termed as subclinical Cushing's syndrome, a definition that is more accurate than preclinical Cushing's syndrome since the evolution towards clinically overt hypercortisolism does occur rarely, if ever. The criteria for qualifying subclinical cortisol excess are controversial and we presently do not have sufficient evidence to define a gold standard for the diagnosis of subclinical Cushing's syndrome. An increased frequency of hypertension, central obesity, impaired glucose tolerance, diabetes and hyperlipoproteinemia has been described in patients with subclinical Cushing's syndrome; however, there is not evidence-based demonstration of its long-term complications and, consequently, the management of this condition is largely empirical. Either adrenalectomy or careful observation associated with treatment of metabolic syndrome has been suggested as treatment options because data are insufficient to indicate the superiority of a surgical or nonsurgical approach to manage patients with subclinical hyperfunctioning adrenal cortical adenomas.

Occult Cushing's syndrome in type-2 diabetes

Subclinical Cushing's syndrome (SCS) caused by adrenal incidentalomas is frequently associated with overweight and insulin resistance. Metabolic syndrome X may therefore be a clue to the presence of CS. However, the incidence of CS in this situation remains unknown. We have conducted a prospective study to evaluate the prevalence of occult CS in overweight, type-2 diabetic patients devoided of specific clinical symptoms of CS. Two hundred overweight, type-2 diabetic patients, consecutively referred for poor metabolic control (HbA(1C) > 8%), were studied as inpatients. A first screening step was performed with the 1-mg overnight dexamethasone suppression test (DST) using a revised criterion for cortisol suppression (60 nmol/liter) to maximize the sensitivity of the procedure. A second confirmatory step of biochemical investigations (midnight plasma cortisol concentration, plasma cortisol circadian rhythm, morning plasma ACTH concentration, 24-h urinary free cortisol, and 4-mg i.v. DST) was performed in patients with impaired 1-mg DST. A third step of imaging studies was performed according to the results of second-step investigations. Fifty-two patients had impaired 1-mg DST. Among these, 47 were further evaluated. Thirty were considered as false positives of the 1-mg DST, whereas 17 displayed at least one additional biological abnormality of the hypothalamic-pituitary-adrenal axis. Definitive occult CS was identified in four patients (2% of the whole series) with Cushing's disease (n = 3) and surgically proven adrenal adenoma (n = 1). Definitive diagnosis remains to be established in seven additional patients (3.5%) with mild occult CS associated with unsuppressed plasma ACTH concentrations and a unilateral adrenal tumor of 10-29 mm in size showing prevalent uptake at radiocholesterol scintigraphy. In conclusion, a relatively high prevalence of occult CS was found in our study. Further studies are needed to evaluate the impact of the cure of occult CS on obesity and diabetes mellitus in these patients. Such studies might provide a rationale for systematic screening of occult CS in this population.

Does subclinical hypercortisolism adversely affect the bone mineral density of patients with adrenal incidentalomas?

OBJECTIVE

Subclinical hypercortisolism (SH) is detected increasingly in a substantial proportion of patients with incidentally discovered adrenal adenomas. The clinical implications of SH are currently unclear. Osteoporosis is a well-known complication of glucocorticoid excess. So far, the impact of SH on bone mineral density (BMD) has been studied in a limited number of reports with discordant results. In the present study we evaluated the BMD in a large cohort of post-menopausal women with adrenal incidentalomas. : patients and measurements Forty-two post-menopausal women with incidentally discovered adrenal masses and radiological features highly suggestive of benign adrenal adenomas were investigated. All patients underwent a standard low-dose dexamethasone suppression test (LDDST; 0.5 mg 6-hourly for 2 days). The diagnosis of subclinical hypercortisolism (SH) was based on post-LDDST cortisol concentrations of > 70 nmol/l. According to this criterion patients were subdivided into two groups: with (n = 18; group A) or without (n = 24; group B) SH. There was no significant difference in age, years since menopause and body mass index between these groups. BMD was measured at L2-L4 vertebrae and three sites of the proximal femur by the dual energy X-ray absorptiometry (DEXA) method.

RESULTS

Post-menopausal women with SH (group A) exhibited slightly but significantly lower absolute and age-adjusted BMD values compared to group B patients in the femoral neck (BMD g/cm2: 0.72 +/- 0.08 vs. 0.79 +/- 0.09; Z-score: -0.20 +/- 0.82 vs. +0.43 +/- 0.94, P < 0.05) and trochanter (BMD g/cm2: 0.60 +/- 0.09 vs. 0.69 +/- 0.10; Z-score: -0.32 +/- 1.0 vs. +0.30 +/- 1.05, P < 0.01). BMD measurements of the Ward's triangle were also lower in group A patients but the difference did not reach statistical significance (BMD g/cm2: 0.60 +/- 0.10 vs. 0.68 +/- 0.13, P = 0.06). There was no difference in the lumbar vertebrae between the two groups (BMD g/cm2: 0.888 +/- 0.13 vs. 0.90 +/- 0.16, P = 0.78; z-score: +0.50 +/- 1.16 vs. +0.11 +/- 1.5, P = 0.36). The number of patients in the osteoporotic range was minimal with no significant difference between the two groups. However, the frequency of osteopenia in group A was significantly greater than in group B patients in the trochanter and Ward's triangle areas. Serum osteocalcin (BGP) levels were significantly lower in group A compared to group B patients (18.6 +/- 8.6 vs. 26.2 +/- 8.1 ng/ml, P < 0.01); no difference existed regarding parathyroid hormone (PTH) concentrations (43 +/- 15.6 vs. 41.2 +/- 14.8 pg/ml, P = 0.72).

CONCLUSIONS

In this series, post-menopausal women with subclinical hypercortisolism had lower absolute and age-adjusted BMD values and a higher rate of osteopaenia in the trabecular loaded and mixed cortical-trabecular bone of proximal femur. These data demonstrate that the subtle hypercortisolism of patients with adrenal incidentalomas may have an adverse effect on the bone mass of these patients.

Overnight dexamethasone suppression test: a reliable screen for Cushing's syndrome in the obese

OBJECTIVE

Reevaluation of the validity of the 1-mg overnight dexamethasone suppression test (ODST) as a screening test for Cushing's syndrome in obese patients.

RESEARCH METHODS AND PROCEDURES

Eighty-six obese patients (body mass index, 30 to 53 kg/m(2)) that were referred to a general endocrine outpatient clinic for evaluation of simple obesity, diabetes mellitus, hypertension, polycystic ovary disease, or pituitary tumor. One milligram dexamethasone was administered orally at 11:00 PM, and serum cortisol levels were measured the following morning between 8:00 AM and 9:00 AM. Suppression of serum cortisol to <80 nM (3 micro g/dL) was chosen as the cut-off point for normal suppression. Patients with serum cortisol levels > or =80 nM were evaluated for Cushing's syndrome.

RESULTS

Suppression of morning cortisol levels to <80 nM occurred in 79 of the 86 obese patients. Seven patients had serum cortisol levels higher than 80 nM; five were eventually diagnosed with Cushing's syndrome and two were considered false positive results in view of normal 24-hour free urinary cortisol and normal suppression on a low dose dexamethasone suppression test (0.5 mg of dexamethasone every 6 hours for 2 days). We found a false positive rate of 2.3% for the ODST using a cut-off serum cortisol of 80 nM.

DISCUSSION

The ODST is a valid screening test for Cushing's syndrome in the obese population. The false positive rate was 2.3%, even when using a strict cut-off serum cortisol of 80 nM. Abnormal cortisol suppression in obese patients should be investigated and not be considered false positive results.

The adrenal incidentaloma: disease of modern technology and public health problem

The optimal strategy for evaluation of a patient with an incidentally discovered adrenal mass is unclear and remains controversial. A prospective multi-center randomized (or even non-randomized) trial would go a long way toward resolving the controversies. However, we lack such a study. Review of the literature supports the view that such patients are at somewhat increased risk of morbidity and mortality and this implies a benefit of early diagnosis for at least for some of the disorders. Our ability to accurately determine clinically those at increased risk among the vast majority who are not at increased risk is poor. We therefore rely on biochemical and radiological diagnostic tests, which have their own limitations. Subjecting patients to unnecessary testing and treatment carries its own set of risks. The diagnostic process itself may contribute considerable anxiety, expense, and if invasive cause pain and other morbidity. The harm that occurs as false positive results are pursued has been termed the "cascade effect" [34]. We must avoid the pitfalls of overestimation of disease prevalence and of the benefits of therapy resulting from advances in diagnostic imaging. In the meantime, we must use our best clinical judgement based upon the best available evidence to ensure that we maximize the benefit to those patients with AI who have clinically significant adrenal disorders and minimize the harm to those who do not.

Pituitary incidentalomas

The optimal strategy for hormonal screening of a patient with any incidentally discovered pituitary mass is unknown. The authors' review of the endocrinologic literature supports the view that such patients are at slightly increased risk for morbidity and mortality. This risk implies a benefit of early diagnosis for at least for some of the disorders, suggesting the importance of case finding. Nevertheless, the data in Table 1 illustrate that clinically diagnosed hormone-secreting pituitary tumors are far less common than incidentalomas. Clinically, one cannot accurately determine the approximately 0.5% of patients with incidentaloma who are at increased risk among the vast majority who are not. Given the limitations of diagnostic tests, effective hormonal screening requires a sufficiently high pretest probability to limit the number of false-positive results. This condition is met to varying degrees in the patient with a small incidentally discovered pituitary mass but no signs or symptoms of hormone excess. Even the more common lesions, such as prolactinoma, are relatively rare. [table: see text] Subjecting patients to unnecessary testing and treatment is associated with risk. In addition to its initial cost, testing may result in further expense and harm as false-positive results are pursued, producing the "cascade effect" described by Mold and Stein as a "chain of events (which) tends to proceed with increasing momentum, so that the further it progresses the more difficult it is to stop." The extensive evaluations performed for some patients with incidentally discovered masses may reflect the unwillingness of many physicians to accept uncertainty, even in the case of an extremely unlikely diagnosis. This unwillingness may be driven, in part, by fear of potential malpractice liability, the failure to appreciate the influence of prevalence data on the interpretation of diagnostic testing, or other factors. The major justification for further evaluation of these patients is not so much to avoid morbidity and mortality for the rare patient who truly is at increased risk but to reassure patients in whom further testing is negative and the physician. Physicians must take care not to create inappropriate anxiety in patients by overemphasizing the importance of an incidental finding unless it is associated with a realistic clinical risk. The authors' recommendations are based on currently available information to minimize the untoward effects of the cascade. As evidence accumulates, these recommendations may need to be revised. The benefit of the diagnosis of an adrenal or pituitary disorder must be considered in the context of the patient's overall condition. Additional studies are needed to analyze the clinical utility of hormonal screening for these common radiologic findings. Data from these studies can be used to identify critical gaps in knowledge and to adopt the epidemiologic methods of evaluation of evidence that have been applied to preventive measures. One must be careful to recognize lead-time bias, in which survival can appear to be lengthened when screening simply advances the time of diagnosis, lengthening the period of time between diagnosis and death without any true prolongation of life; and length bias, which refers to the tendency of screening to detect a disproportionate number of cases of slowly progressive disease and to miss aggressive cases that, by virtue of rapid progression, are present in the population only briefly. Physicians must avoid the pitfalls of overestimation of disease prevalence and of the benefits of therapy resulting from advances in diagnostic imaging. Clinical judgment based on the best available evidence should be complemented and not replaced by laboratory data.

Subclinical Cushing's syndrome

Classic Cushing's syndrome is a rare disease with an estimated incidence of 1 case per 100,000 persons. With routine use of imaging techniques such as ultrasound and CT, adrenal masses are being detected with increased frequency. A substantial percentage of these incidentalomas are hormonally active, with 5% to 20% of the tumors producing glucocorticoids. Autonomous glucocorticoid production without specific signs and symptoms of Cushing's syndrome is termed subclinical Cushing's syndrome. With an estimated prevalence of 79 cases per 100,000 persons, subclinical Cushing's syndrome is much more common than classic Cushing's syndrome. Depending on the amounts of glucocorticoids secreted by the tumor, the clinical spectrum ranges from slightly attenuated diurnal cortisol rhythm to complete atrophy of the contralateral adrenal gland with lasting adrenal insufficiency after unilateral adrenalectomy. Patients with subclinical Cushing's syndrome lack the classical stigmata of hypercortisolism but have a high prevalence of obesity, hypertension, and type 2 diabetes. All patients with incidentally detected adrenal masses scheduled for surgery must undergo testing for subclinical Cushing's syndrome to avoid postoperative adrenal crisis. The best screening test to uncover autonomous cortisol secretion is the short dexamethasone suppression test. Because the adrenal origin of a pathologic cortisol secretion is anticipated, the author prefers a higher dexamethasone dose (3 mg instead of 1 mg) to reduce false-positive results. A suppressed serum cortisol level of less than 3 micrograms/dL (80 nmol/L) after dexamethasone excludes significant cortisol secretion by the tumor. A serum cortisol level greater than 3 micrograms/dL requires further investigation, including confirmation by high-dose dexamethasone (8 mg) suppression testing, a CRH test, and analysis of diurnal rhythm. Determination of urinary free cortisol is less useful because increased values are a late finding usually associated with emerging clinical signs of Cushing's syndrome. Patients with suppressed plasma ACTH in response to CRH generally have adrenal insufficiency after surgery and require adequate perioperative and postoperative substitution therapy. Whether patients with subclinical Cushing's syndrome should undergo adrenalectomy is a matter of debate. The author performs surgery in young patients (< 50 years), in patients with suppressed plasma ACTH, and in patients with a recent history of weight gain, substantial obesity, arterial hypertension, diabetes mellitus, and osteopenia. In completely asymptomatic patients with normal plasma ACTH concentrations and in patients older than 75 years, the author recommends a nonsurgical approach. A large prospective randomized study is necessary to evaluate the benefits of surgery versus conservative treatment in patients with subclinical Cushing's syndrome.

Management approaches to adrenal incidentalomas. A view from Rochester, Minnesota

Two biproducts of the revolution in diagnostic imaging techniques are unintended discoveries, and uncertainty for the patient and the clinician. To address the uncertainty associated with adrenal incidentalomas, clinicians need to understand the definition, differential diagnosis, and options for assessment with respect to functional status and malignancy potential. This article presents an algorithmic approach that addresses these issues.

Management approaches to adrenal incidentalomas. A view from Ancona, Italy

The definition of adrenal incidentaloma encompasses a heterogeneous spectrum of pathologic entities, including primary adrenocortical and medullary tumors, benign or malignant lesions, hormonally active or inactive lesions, metastases, and infections. This article provides an overview of the diagnostic clinical approach and management of the incidentally discovered adrenal masses. Approaches are based on data collected in more than 1000 cases of the Collaborative Study Group on Adrenal Incidentaloma of the Italian Society of Endocrinology and the authors' experience.

Risk factors and long-term follow-up of adrenal incidentalomas

The natural course of adrenal incidentalomas and the risk that such lesions evolve toward hormonal hypersecretion or malignancy are still under evaluation. Of 246 consecutive patients with adrenal incidentaloma studied at our institution in the last 15 yr, 91 underwent surgery. Of the remaining patients, a group of 75 (52 females and 23 males; median age, 56 yr; range, 19-77 yr) with incidentally discovered asymptomatic adrenal masses (60 unilateral and 15 bilateral; median diameter, 2.5 cm; range, 1.0-5.6) was enrolled in an endocrine and morphological follow-up of at least 2 yr after diagnosis (median, 4 yr; range, 2-10). During follow-up, no patients developed malignancy; 9 showed mass enlargement, with appearance of a new mass in the contralateral gland in 2; 3 developed adrenal hyperfunction (overt Cushing's syndrome in 2, nonclinical hypercortisolism in 1); and 3 showed adrenal mass enlargement associated with adrenal hyperfunction (nonclinical hypercortisolism in 2, pheochromocytoma in 1). The estimated cumulative risks to develop mass enlargement and hyperfunction were 8% and 4%, respectively, after 1 yr, 18% and 9.5% after 5 yr, and 22.8% and 9.5% after 10 yr. Nine risk factors for adrenal mass enlargement or hyperfunction were arbitrarily selected and evaluated: sex, age, presence of obesity, hypertension, diabetes, abnormal endocrine tests, mass size, mass location, and scintigraphic uptake pattern. Three of them attained statistical significance: mass size of 3 cm or more at diagnosis and exclusive radiocholesterol uptake by the mass at scintigraphy had relevance for the occurrence of adrenal hyperfunction, whereas the presence of endocrine test abnormalities at diagnosis had predictive value for mass enlargement. It is concluded that subtle hormonal abnormalities are risk factors for mass size increase, which is not a sign of malignant transformation. Both mass size of 3 cm or more at diagnosis and exclusive radiocholesterol uptake, indicating higher risks of hyperfunction, should be considered to plan a more thorough endocrine follow-up.