Reduced serum levels of dehydroepiandrosterone sulphate in adrenal incidentalomas: a marker of adrenocortical tumour

Influence of sex and functional status on the value of serum steroid profiling in discriminating adrenocortical carcinoma from adrenocortical adenoma

Background

It is challenging for clinicians to distinguish adrenocortical carcinoma (ACC) from benign adrenocortical adenomas (ACA) in their early stages. This study explored the value of serum steroid profiling as a complementary biomarker for malignancy diagnosis of ACC other than diameter and explored the influence of sex and functional status.

Methods

In this retrospective study, a matched cohort of patients diagnosed with either ACC or ACA based on histopathology was meticulously paired in a 1:1 ratio according to sex, age, and functional status. Eight serum steroids including 11-deoxycortisol, 11-deoxycorticosterone, progesterone, androstenedione, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone, and estradiol, were quantified by liquid chromatography tandem mass spectrometry. We conducted a comparative analysis of the clinical characteristics and serum steroid profiles of patients with ACC and ACA, with further subgroup analysis.

Results

The study included 31 patients with ACC and 31 matched patients with ACA. Patients with ACC exhibited significantly larger tumor diameters, lower body mass index (BMI), and higher levels of 11-deoxycortisol, progesterone, and androstenedione than those with ACA. 11-deoxycortisol was the only valuable index for discriminating ACC from ACA, regardless of functional status and sex. Progesterone, DHEA, and DHEAS levels were higher in the functional ACC group than in the non-functional ACC group. Female ACC patients, especially in postmenopausal female exhibited higher levels of androstenedione than male patients. The area under the curve of tumor diameter, 11-deoxycortisol, and BMI was 0.947 (95% CI 0.889-1.000), with a sensitivity of 96.8% and specificity of 90.3%.

Conclusion

Serum steroid profiling serves as a helpful discriminative marker for ACC and ACA, with 11-deoxycortisol being the most valuable marker. For other steroid hormones, consideration of sex differences and functional status is crucial.

Prevalence of Functioning Adrenal Incidentalomas: A Systematic Review and Meta-analysis

CONTEXT

Adrenal hyperfunction is associated with an increased risk of cardiometabolic complications in subjects with adrenal incidentaloma (AI). Reliable prevalence estimates of functioning AIs are important to direct resources allocations.

OBJECTIVE

To assess the prevalence of autonomous/possible autonomous cortisol secretion (ACS), primary aldosteronism (PA), pheochromocytoma (PHEO), and Cushing syndrome (CS) in patients with AI.

METHODS

We performed a comprehensive search of multiple databases (PubMed, Ovid MEDLINE, Web of Science) for potentially relevant studies without language restriction, up to February 2022. Of the 1661 publications evaluated at title and abstract levels, 161 were examined as full text and 36 were included. Study level clinical data were extracted by 3 independent reviewers.

RESULTS

The overall prevalence of functioning AIs was 27.5% (95% CI 23.0, 32.5). ACS/possible ACS, with a prevalence of 11.7% (95% CI 8.6, 15.7), was the most frequent hormonal alteration, while PA occurred in 4.4% of the patients (95% CI 3.1, 6.2). Subgroup analysis showed that PA was more prevalent in patients from Asia than in patients from Europe/America; in contrast, ACS/possible ACS had a lower prevalence in Asian countries. At meta-regression analysis, the prevalence of ACS/possible ACS was influenced by the proportion of female patients, while the prevalence of PA was positively associated with the proportion of patients with hypertension and the publication year. Finally, PHEO and CS prevalence were 3.8% (95% CI 2.8, 5.0) and 3.1% (95% CI 2.3, 4.3) respectively.

CONCLUSION

This meta-analysis provides extensive data on the prevalence of functioning AIs and the factors affecting heterogeneity in prevalence estimates.

Steroid Sulfation in Adrenal Tumors

CONTEXT

The adrenal cortex produces specific steroid hormones including steroid sulfates such as dehydroepiandrosterone sulfate (DHEAS), the most abundant steroid hormone in the human circulation. Steroid sulfation involves a multistep enzyme machinery that may be impaired by inborn errors of steroid metabolism. Emerging data suggest a role of steroid sulfates in the pathophysiology of adrenal tumors and as potential biomarkers.

EVIDENCE ACQUISITION

Selective literature search using "steroid," "sulfat*," "adrenal," "transport," "mass spectrometry" and related terms in different combinations.

EVIDENCE SYNTHESIS

A recent study highlighted the tissue abundance of estrogen sulfates to be of prognostic impact in adrenocortical carcinoma tissue samples using matrix-assisted laser desorption ionization mass spectrometry imaging. General mechanisms of sulfate uptake, activation, and transfer to substrate steroids are reasonably well understood. Key aspects of this pathway, however, have not been investigated in detail in the adrenal; these include the regulation of substrate specificity and the secretion of sulfated steroids. Both for the adrenal and targeted peripheral tissues, steroid sulfates may have relevant biological actions beyond their cognate nuclear receptors after desulfation. Impaired steroid sulfation such as low DHEAS in Cushing adenomas is of diagnostic utility, but more comprehensive studies are lacking. In bioanalytics, the requirement of deconjugation for gas-chromatography/mass-spectrometry has precluded the study of steroid sulfates for a long time. This limitation may be overcome by liquid chromatography/tandem mass spectrometry.

CONCLUSIONS

A role of steroid sulfation in the pathophysiology of adrenal tumors has been suggested and a diagnostic utility of steroid sulfates as biomarkers is likely. Recent analytical developments may target sulfated steroids specifically.

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.

Adrenal Incidentaloma

An adrenal incidentaloma is now established as a common endocrine diagnosis that requires a multidisciplinary approach for effective management. The majority of patients can be reassured and discharged, but a personalized approach based upon image analysis, endocrine workup, and clinical symptoms and signs are required in every case. Adrenocortical carcinoma remains a real concern but is restricted to <2% of all cases. Functional adrenal incidentaloma lesions are commoner (but still probably <10% of total) and the greatest challenge remains the diagnosis and optimum management of autonomous cortisol secretion. Modern-day surgery has improved outcomes and novel radiological and urinary biomarkers will improve early detection and patient stratification in future years to come.

Correlation Between Size and Function of Unilateral and Bilateral Adrenocortical Nodules: An Observational Study

OBJECTIVE. Adrenal incidentalomas occur in 5% of adults and can produce autonomous cortisol secretion that increases the risk of metabolic syndrome and cardiovascular disease. The objective of our study was to evaluate the relationship between adrenal nodule size measured on CT and autonomous cortisol secretion. SUBJECTS AND METHODS. In a prospective study of 73 patients 22-87 years old with incidentalomas, unilateral in 52 patients and bilateral in 21 patients, we measured maximum nodule diameter on CT and serum cortisol levels at 8:00 am, 60 minutes after the adrenocorticotropic hormone stimulation test, and after the dexamethasone suppression test. We also studied 34 age-, sex-, and body mass index-matched control subjects. Statistics used were Spearman correlation coefficients, t tests, ANOVA test, and multivariate analysis. RESULTS. The mean maximum diameter of unilateral nodules measured on CT was larger on the right (2.47 ± 0.98 [SD] cm) than on the left (2.04 ± 0.86 cm) (p = 0.01). In the bilateral cases, the mean diameter of the right nodules was 2.69 ± 0.93 cm compared with 2.13 ± 0.89 cm on the left (p = 0.06). Mean baseline serum cortisol level was significantly higher in the patients with incidentalomas (bilateral, 13.1 ± 4.5 mcg/dL [p < 0.001]; unilateral, 9.7 ± 3.2 mcg/dL [p = 0.019]) than in the control subjects (7.5 ± 3.6 mcg/dL). After dexamethasone suppression test, serum cortisol levels were suppressed to less than 1.8 mcg/dL in 100% of control subjects, 33% of patients with bilateral incidentalomas, and 62% of patients with unilateral incidentalomas (p < 0.001). There were significant correlations between maximum nodule diameter on CT and serum cortisol levels after the dexamethasone suppression test (ρ = 0.500; p < 0.001) and at baseline (ρ = 0.373; p = 0.003). CONCLUSION. Increasing size of adrenal nodules is associated with more severe hyper-cortisolism and less dexamethasone suppression; these cases need further evaluation and possibly surgery because of increased risks of metabolic syndrome and cardiovascular mortality.

No Postoperative Adrenal Insufficiency in a Patient with Unilateral Cortisol-Secreting Adenomas Treated with Mifepristone Before Surgery

BACKGROUND

Glucocorticoid replacement is commonly required to treat secondary adrenal insufficiency after surgical resection of unilateral cortisol-secreting adrenocortical adenomas. Here, we describe a patient with unilateral cortisol-secreting adenomas in which the preoperative use of mifepristone therapy was associated with recovery of the hypothalamic-pituitary-adrenal (HPA) axis, eliminating the need for postoperative glucocorticoid replacement.

CASE PRESENTATION

A 66-year-old Caucasian man with type 2 diabetes mellitus, hyperlipidemia, hypertension, and obesity was hospitalized for Fournier's gangrene and methicillin-resistant Staphylococcus aureus sepsis. Abdominal computed tomography scan revealed three left adrenal adenomas measuring 1.4, 2.1, and 1.2 cm and an atrophic right adrenal gland. Twenty-four-hour urinary free cortisol level was elevated (237 µg/24 hours, reference range 0-50 µg/24 hours). Hormonal evaluation after resolution of the infection showed an abnormal 8 mg overnight dexamethasone suppression test (cortisol postdexamethasone 14.5 µg/dL), suppressed adrenocorticotropic hormone (ACTH; <5 pg/mL, reference range 7.2-63.3 pg/mL), and low-normal dehydroepiandrosterone sulfate (50.5 µg/dL, male reference range 30.9-295.6 µg/dL). Because of his poor medical condition and uncontrolled diabetes, his Cushing's syndrome was treated with medical therapy before surgery. Mifepristone therapy was started and, within five months, his diabetes was controlled and insulin discontinued. The previously suppressed ACTH increased to above normal range accompanied by an increase in dehydroepiandrosterone sulfate levels, indicating recovery of the HPA axis and atrophic contralateral adrenal gland. The patient received one precautionary intraoperative dose of hydrocortisone and none thereafter. Two days postoperatively, ACTH (843 pg/mL) and cortisol levels (44.8 µg/dL) were significantly elevated, reflecting an appropriate HPA axis response to the stress of surgery, and two weeks postoperatively, ACTH was within normal range and a repeat dexamethasone suppression test was normal. Six months postoperatively, ACTH was within normal limits and cortisol was approaching normal. The patient has exhibited no postoperative signs or symptoms of adrenal insufficiency in 12 months.

CONCLUSION

Preoperative mifepristone therapy was associated with apparent recovery of the HPA axis prior to unilateral adrenalectomy in a patient with unilateral adrenal adenomas. Postoperatively, the patient experienced no signs or symptoms of adrenal insufficiency and no glucocorticoid replacement was required.

Clinical characteristics and follow-up of Korean patients with adrenal incidentalomas

BACKGROUND/AIMS

We investigated the clinical characteristics and follow-up findings of subjects with adrenal incidentalomas in a single, tertiary-care hospital in South Korea.

METHODS

The study consisted of a retrospective analysis of 282 adrenal incidentaloma patients who underwent radiographic and endocrinological evaluations at Samsung Medical Center in Seoul, South Korea, between January 2004 and July 2011.

RESULTS

Most (86.2%) of the subjects were found to have nonfunctioning tumors. Functioning tumors were seen in 39 patients (13.8%). Among them, 28 (9.9%) had subclinical Cushing syndrome (SCS), six (2.1%) had pheochromocytoma, and five (1.8%) had primary hyperaldosteronism. Malignant adrenal tumors were discovered in three cases: two (0.7%) were primary adrenal cancers, and one (0.4%) was a secondary metastasis from a lung cancer. Significant risk factors for functional tumors were female gender (odds ratio [OR], 3.386; 95% confidence interval [CI], 1.611 to 7.117; p = 0.0013) and a noncontrast attenuation value of > 10 Hounsfield units (OR, 2.806; 95% CI, 1.231 to 6.397; p = 0.0141). During follow-up (mean, 22.5 months) of 72 of the patients, three (4.2%) developed hormonal changes due to functional tumors. One was confirmed as pheochromocytoma by histopathology, and the others were diagnosed with SCS and followed routinely without surgical intervention. No malignant transformation was found in these patients.

CONCLUSIONS

Based on these findings, initial hormonal and radiographic evaluations for adrenal incidentalomas appear to be more important than follow-up tests because functional or malignant changes are rare.

The prevalence and relevance of adrenal masses in patients with sporadic gastroenteropancreatic neuroendocrine tumours (GEP-NET)

OBJECTIVE

The widespread application of abdominal computerized tomography (CT) imaging has revealed that 0.98-4.0% of individuals harbour adrenal lesions (incidentalomas). There is, however, paucity of information regarding the prevalence of adrenal lesions in patients with gastroenteropancreatic neuroendocrine tumours (GEP-NETS). Purpose of this study was to estimate the prevalence of adrenal lesions in patients with GEP-NETS and identify their radiological features and clinical significance.

DESIGN

The prevalence of adrenal lesions was estimated retrospectively in 438 patients with GEP-NETS who underwent abdominal imaging. Secretory status and changes in size were documented during subsequent follow-up. MEN-1 patients and ectopic ACTH-secreting tumours were excluded.

RESULTS

Adrenal lesions were detected in 32 (8.4%) of 383 patients included. The majority (22 patients - 69%) were located at the left adrenal gland and the mean size was 23.6 mm. In two patients, one with a well and another with a poorly differentiated tumour, clinicopathological features suggested adrenal metastases. During a mean follow-up period of 69.5 months, no subsequent growth of any adrenal lesion was observed. Endocrine evaluation documented subclinical glucocorticoid hypersecretion in 4 cases (14%). The presence of adrenal lesions did not correlate to distant metastases, however, they were observed more frequently in patients with G3 tumours.

CONCLUSION

The prevalence of adrenal lesions in patients with GEP-NETs was found to be higher than the general population and mostly represent benign adrenal adenomas (except patients with G3 tumours). Nevertheless, individualized assessment of imaging characteristics should be still considered.

Serum dehydroepiandrosterone sulfate concentration is lower in women with primary aldosteronism

OBJECTIVE

The objective of this article is to measure serum dehydroepiandrosterone sulfate (DHEA-S) concentration in both genders with primary aldosteronism (PA).

MATERIALS AND METHODS

The study enrolled 78 subjects with normal controls, 46 subjects with essential hypertension and 85 subjects with PA from October 2007 to June 2011. Subjects with PA were divided into three subtype groups: aldosterone-producing adenoma (APA), bilateral idiopathic hyperplasia (IHA) and PA with negative imaging findings.

RESULTS

Women with PA (n = 49) had lower serum DHEA-S levels compared with normal controls and subjects with essential hypertension (p < 0.01). In subtype analysis, only female APAs had lower serum DHEA-S levels (p < 0.01 compared with normal controls, p < 0.01 compared with subjects with essential hypertension). In APA, a significant correlation between tumor size and serum DHEA-S was found in women (p < 0.01).

CONCLUSION

Our data suggested that serum DHEA-S levels are lower in women with PA. In subtype groups, only women with APA had lower serum DHEA-S. There was no significant difference between subjects with bilateral essential hyperplasia, PA with negative imaging findings, normal controls and subjects with essential hypertension in both genders. The serum DHEA-S level is negatively correlated with the size of APA.

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.

Management of adrenal incidentaloma

The term adrenal incidentaloma covers a wide spectrum of adrenal pathologies sharing the method of discovery. The management of adrenal incidentaloma is controversial, and clinicians should determine whether the patient's health is affected by the presence of a tumor. Critical points in management include differentiating benign from malignant and hormonally active from nonfunctional adrenal masses. The probability of malignancy is related to tumor size and imaging phenotype. Masses smaller than 4 cm in diameter that exhibit low attenuation by unenhanced CT scan and rapid contrast washout by delayed contrast-enhanced CT scan are probably benign. All patients with adrenal incidentaloma should undergo biochemical evaluations for pheochromocytoma and subclinical or overt Cushing's syndrome, and hypertensive patients should undergo biochemical testing for hyperaldosteronism. Laparoscopic adrenalectomy is the treatment of choice in all hypersecretory tumors. If adrenocortical carcinoma is suspected, an open adrenalectomy is recommended. Patients who are not candidates for surgical resection of the tumor should be monitored radiographically for 2 years, and hormonal follow-up should be performed annually for 4 years.

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.

Adrenal incidentaloma: a diagnostic challenge

The widespread application of abdominal imaging procedures has resulted in an increased frequency of clinically silent adrenal masses. Adrenal incidentaloma (AI) is a term applied to an accidentally discovered adrenal mass on imaging performed for the investigation of an unrelated complaint. Adrenal incidentalomas (AIs) are a cluster of different pathologies, the majority of which are benign and non-functioning adrenal adenomas. However, mild hormonal alterations as well as metabolic abnormalities may be present in patients with AIs. Thus, a multidisciplinary approach with biochemical and radiologic evaluation is needed to characterize these lesions and identify patients who are at high risk for hormonal or malignant evolution. Significant new information has helped resolve controversies regarding the most reliable approach to this clinical problem. The present review considers the prevalence, pathology and natural history of AIs. We also discuss the reliability of available screening methods and localization techniques and consider optimal management and follow-up strategies.

Adrenal incidentalomas and subclinical Cushing's syndrome: diagnosis and treatment

PURPOSE OF REVIEW

Adrenal incidentaloma has become a frequent clinical dilemma. Even in the absence of specific clinical features of Cushing's syndrome, adrenocortical incidentalomas may display steroid secretory activity at different degrees. The recognition of endocrine and metabolic dysfunctions associated with subclinical hypercortisolism leads to current awareness about its potential consequences.

RECENT FINDINGS

Different protocols and threshold values to define normal cortisol secretion and diagnosis of subclinical Cushing's syndrome have been proposed, including recent practice guidelines for the diagnosis of overt Cushing's syndrome. Follow-up studies have provided additional data about the natural course of the disease and related cardiovascular and metabolic consequences. The study of bilateral adrenocorticotropin-independent macronodular adrenocortical hyperplasia in some familial cases offers a new approach to understanding the spectrum of subclinical cortisol hypersecretion.

SUMMARY

The prevalence of subclinical hypercortisolism may be higher than previously reported as more sensitive diagnostic criteria are now recommended. The absence of a single gold standard test, the diversity of diagnostic criteria and the requirement of subsequent meticulous biochemical evaluations before a decision for treatment represent a challenge for the clinical management of this condition.

Subclinical Cushing's syndrome

Subclinical Cushing's syndrome (CS) is attracting increasing interest since the serendipitous discovery of an adrenal mass has become a rather frequent event owing to the routine use of sophisticated radiologic techniques. 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 feedback, in 5 to 20% of cases depending on study protocols and diagnostic criteria. The criteria for qualifying subclinical cortisol excess are controversial and presently there is no consensus on a gold standard for the diagnosis of this condition. An increased frequency of hypertension, central obesity, impaired glucose tolerance, diabetes and hyperlipemia has been described in patients with subclinical CS; however, there is still no clear demonstration of the long-term complications of this condition whose management remains largely empirical. Either adrenalectomy or careful observation associated with treatment of the metabolic syndrome have been suggested as treatment options.

Benign cortisol-secreting adrenocortical adenomas produce small amounts of androgens

BACKGROUND

Serum androgen levels are below normal in patients with benign cortisol-secreting adrenocortical adenomas, owing to ACTH suppression. Associated androgen secretion is usually considered as indicative of malignancy. The objective of the study was to analyse the androgen-producing ability of cortisol-secreting adrenocortical adenomas.

DESIGN

Retrospective data collection in a single referral hospital centre.

METHODS

Dehydroepiandrosterone sulfate (DHEAS), Delta4androstenedione and testosterone concentrations were measured before and after adrenalectomy and then at 6-month intervals in 20 women (eight cortisol-secreting adrenocortical adenomas, six subclinical cortisol-secreting adrenocortical adenomas, and six nonfunctional adenomas).

RESULTS

Before adrenalectomy, serum androgen concentrations were measurable in all women with clinically apparent and subclinical cortisol-secreting adrenocortical adenomas. DHEAS levels were either at the lower end of the normal range or below normal, but were always clearly detectable. Postoperatively, during adrenocortical insufficiency, DHEAS, Delta4androstenedione and testosterone concentrations fell to near the detection limit in all patients with cortisol-secreting adrenocortical adenomas (P = 0.008 for each marker) and showed a similar tendency to fall in all patients with subclinical cortisol-secreting adrenocortical adenomas. Pre- and post-treatment androgen concentrations did not differ in patients with nonfunctional adenomas. Immunohistochemical analysis confirmed CYP17, HSD3B2, SULT2A1 and CYB5 expression by all cortisol-producing tumours. The intensity of CYP17 and SULT2A1 expression was stronger in cortisol-secreting adenomas than in their adjacent normal adrenal tissue.

CONCLUSION

Both clinically apparent and subclinical cortisol-secreting adrenocortical adenomas appear to show moderate autonomous androgen production. Thus, weak androgen secretion in patients with adrenocortical tumours should not necessarily be considered as a sign of malignancy.

Differential diagnosis and imaging in Cushing's syndrome

Establishing the cause of Cushing's syndrome (CS) is one of the most challenging processes in clinical endocrinology. Biochemical testing, including measurement of plasma adrenocorticotropin (ACTH), high-dose dexamethasone suppression, and corticotropin-releasing hormone stimulation testing, is integral to the differential diagnosis. No existing test has sufficient diagnostic accuracy when used alone, however. The adjunctive use of focused imaging, including CT, MRI, and nuclear imaging modalities, often can provide a diagnosis. In patients with ACTH-dependent CS, bilateral inferior petrosal sinus sampling can facilitate a diagnosis in those with discrepant clinical features, biochemistry, or imaging. This article focuses on current biochemical and radiologic strategies for the differential diagnosis of CS.

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.

Adrenal tumors: how to establish malignancy ?

Discerning malignancy in adrenal tumors largely influences disease management and is, therefore, of utmost importance to both patient and physician. Clinical presentation (e.g. virilization) and baseline hormonal evaluation (e.g. high serum DHEAS) are occasionally of great value but usually provide only limited help in predicting malignancy. The probability of malignancy is clearly related to tumor size, as almost all lesions <3 cm are benign whereas a diameter of >6 cm indicates a high risk of malignancy. Computed tomography (CT) and magnetic resonance imaging (MRI) both contribute significantly to the characterization of adrenal masses. If the attenuation of a homogeneous mass with smooth border is 10 Hounsfield units or less in unenhanced CT the diagnosis of a lipid rich adenoma is established. Similarly, enhancement washout of more than 50% in CT at 10-15 min suggests a benign lesion. In MRI both rapid contrast enhancement after gadolinium followed by rapid washout and signal intensity loss using opposed-phase image in chemical shift analysis also indicate the presence of an adenoma. In contrast, adrenal carcinomas--but also pheochromocytomas--typically present as inhomogeneous lesion with intermediate-to-high intensity on T2 images in MRI. Margins and enhancement after contrast media in CT are irregular in adrenal carcinoma. Other imaging techniques either offer little additional information (NP-59 scintigraphy) or have not yet been fully established (positron emission tomography). Fine needle aspiration/cut biopsy is at present restricted to patients with a known extra-adrenal malignancy and suspected adrenal metastasis as the only evidence of disseminated disease. Adrenal tumors classified as benign undergo follow-up imaging to assess tumor growth. If an increase in diameter of >1 cm is seen, surgical removal is recommended. Even after tumor removal the diagnosis of dignity may remain difficult. Diagnostic scores together with new immunohistological markers are the methods of choice to assess malignancy. In conclusion, an interdisciplinary approach with a structured use of available diagnostic tools is needed to classify adrenal tumors correctly.

The clinically inapparent adrenal mass: update in diagnosis and management

Clinically inapparent adrenal masses are incidentally detected after imaging studies conducted for reasons other than the evaluation of the adrenal glands. They have frequently been referred to as adrenal incidentalomas. In preparation for a National Institutes of Health State-of-the-Science Conference on this topic, extensive literature research, including Medline, BIOSIS, and Embase between 1966 and July 2002, as well as references of published metaanalyses and selected review articles identified more than 5400 citations. Based on 699 articles that were retrieved for further examination, we provide a comprehensive update of the diagnostic and therapeutic approaches focusing on endocrine and radiological features as well as surgical options. In addition, we present recent developments in the discovery of tumor markers, endocrine testing for subclinical disease including autonomous glucocorticoid hypersecretion and silent pheochromocytoma, novel imaging techniques, and minimally invasive surgery. Based on the statements of the conference, the available literature, and ongoing studies, our aim is to provide practical recommendations for the management of this common entity and to highlight areas for future studies and research.

Management of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare neoplasm with poor prognosis. Patients present with signs of steroid hormone excess (e.g. Cushing's syndrome, virilization) or an abdominal mass. Tumour size at presentation (mean diameter at diagnosis > 10 cm) is the most important indicator of malignancy. In addition, computed tomography (CT) typically demonstrates an inhomogeneous adrenal lesion with irregular margins and variable enhancement of solid components after intravenous contrast media. Magnetic resonance imaging (MRI) is equally effective as CT and is particularly helpful to visualize invasion into large vessels. Complete tumour removal (R0 resection) offers by far the best chance for long-term survival and therefore surgery is the treatment of choice in stage I-III ACC. Despite tumour resection for cure most patients will eventually develop local recurrence or distant metastases. Thus adjuvant treatment options need to be evaluated in high-risk patients (e.g. radiation therapy of the tumour bed and/or chemotherapy). In tumour recurrence re-operation should always be considered. In metastatic disease (stage IV ACC) not amenable to surgery mitotane (o,p'DDD) remains the first-line therapy. Drug monitoring is needed for effective treatment aiming at concentrations between 14 and 20 mg/l. Patients not responding to mitotane may benefit from cytotoxic chemotherapy (23% partial remissions, 4% complete remissions). Only large prospective multicentre trials comparing different treatment options will allow to make systematic progress in the management of ACC.

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.

Adrenal incidentaloma--experience of a standardized diagnostic programme in the Swedish prospective study

OBJECTIVE

To report the 5-year experience of a diagnostic programme for adrenal incidentaloma with special emphasis to diagnose hormonally active and malignant lesions.

DESIGN

A prospective study in which new cases of adrenal incidentalomas in Sweden have been evaluated by a standardized diagnostic protocol between January 1996 and July 2001.

SETTING

Thirty-three different Swedish hospitals have contributed with cases.

SUBJECTS

A total of 381 patients (217 females, 164 males) with adrenal incidentalomas were studied.

INTERVENTIONS

Diagnostic procedures were undertaken according to a standardized programme. Operation was recommended if the incidentaloma had a size of more than 3-4 cm or if there was a suspicion of a hypersecreting tumour.

MAIN OUTCOME MEASURES

The size of the incidentaloma, clinical characteristics of the patients and results of biochemical diagnostic tests were registered.

RESULTS

The median age of the patients was 64 years (18-84 years), and the median size of the incidentalomas was 3 cm (1-20 cm). A total of 85(22%) patients were operated. Twenty of these patients were diagnosed with a benign hypersecreting tumour and 14 with a malignant tumour. Fourteen of 15 operated patients with diagnosed pheochromocytoma had elevated 24-h urinary noradrenaline and all of the patients operated because of a biochemical suspicion of aldosterone or cortisol hypersecretion (n = 6) were found to have adrenal adenomas. Of the 14 operated patients with malignant diseases, 10 were adrenal carcinomas (median size 10 cm; range 4-16 cm). In a multiple logistic regression model, incidentaloma size was significantly associated with the risk of a malignant tumour (P = 0.009), and there was a tendency of an association between age/male sex and the risk of a malignancy (both, P = 0.07).

CONCLUSION

In this Swedish multicentre study of 381 cases with adrenal incidentalomas, 5% had benign hypersecreting tumours and nearly 4% had malignant tumours. The results of the biochemical diagnostic tests used had a high compatibility with the histological diagnosis found at operation in the patients with hypersecreting tumours. Tumour size, male gender and high age were predictive for the risk of a malignant tumour. A follow-up of the patients is warranted in order to establish whether there are undiscovered cases of malignant or hypersecreting tumours amongst the nonoperated patients.

Evaluation and management of adrenal masses

BACKGROUND

The widespread use of abdominal imaging has led to increased detection of adrenal tumors. The significance of these masses, as well as the optimal management approach to treatment, has generated some controversy regarding further evaluation and therapy.

METHODS

The authors reviewed the literature regarding the evaluation and management of these masses, particularly adrenal incidentalomas. Based on their institutional experience, they propose a diagnostic, evaluation, and management algorithm for treating adrenal masses.

RESULTS

Appearance and clinical history should indicate how to perform the biochemical evaluation, keeping in mind that the presence of pheochromocytomas must be ruled out. Radiological evaluation by CT or MRI provides useful parameters to identify malignant lesions. Surgery is indicated for masses that are larger than 5 cm in diameter or suspected of malignancy. Fine-needle aspiration biopsy should be used when other extra-adrenal malignancies are suspected and after pheochromocytoma has been ruled out.

CONCLUSIONS

Careful analysis of each adrenal mass is essential to effectively avoid potential problems. Guidelines to manage patients with adrenal masses are needed.

Adrenal incidentalomas

The term adrenal incidentaloma refers to an adrenal mass occasionally and unexpectedly discovered by an abdominal imaging procedure performed for reasons a priori unrelated to adrenal dysfunction. The prevalence of adrenal incidentalomas as discovered by computed tomographic scan examination is estimated to be between 1% and 4%. The vast majority of these lesions are of adrenocortical origin, most often adenomas. Identification of steroid or catecholamine-secreting tumors is important but usually solved with appropriate endocrinologic investigations. A difficult problem, however, is to distinguish between benign and malignant primary or secondary tumors. Size less than 4 cm and an unenhanced computed tomographic attenuation under 10 Hounsfield Units (HU) are findings in favor of a benign adrenocortical adenoma, as is a positive NP 59 scintigraphic examination. The pathogenesis of adrenal tumors is not well understood. However, alterations of the cyclic AMP signalling pathway have recently been observed in benign adrenocortical lesions and molecular defects associated with insulin-like growth factor-II overexpression in malignant adrenocortical tumors.

The natural history of incidentally discovered adrenocortical adenomas: a retrospective evaluation

Adrenal adenoma is the most frequent lesion among adrenal incidentalomas. The present retrospective study was undertaken to investigate medium-term evolution of supposed or ascertained adrenocortical adenomas in a group of 53 subjects (16 males and 37 females, aged 31-83 yr), with bilateral (no.=8) or monolateral (no.=45) incidentally discovered adrenal masses (size 10-50 mm, median 25 mm), who were followed-up for 6-78 months (median 24 months). Diagnosis of adenoma was based on size and morphovolumetric aspect of the lesion at computed tomography (CT), scintigraphic pattern using NP59 as a tracer, and it was histologically confirmed in 7 patients. After an extensive hormonal investigation including morning (no.=53) and midnight (no.=28) serum cortisol, plasma ACTH (no.=50), serum DHEAS (no.=51), daily urinary free cortisol excretion (no.=52), post-dexamethasone (1 mg) cortisol (no.=42) and ACTH stimulation test for 17-hydroxyprogesterone (17-OHP) response (no.=48) at the time of diagnosis, patients were periodically re-evaluated for hormonal function and radiological aspect of the lesion(s) by CT. Seven patients underwent surgery 6-42 months after incidentaloma demonstration, with histological diagnosis of adrenal adenoma. During follow-up an increase in the size of the lesion was demonstrated in 22 patients (41.5%); the increase was greater than 10 mm in 8 cases. In 3 patients with unilateral mass, a contralateral lesion appeared 10-52 months after first demonstration. Six patients (11.3%) showed reduction or disappearance of the lesions. On the basis of the hormonal evaluation 3 patients were considered to have subclinical Cushing's syndrome and 10 patients exhibited 17-OHP hyperresponse to ACTH test consistent with partial 21 -hydroxylase deficiency. A significant difference in the size of the lesions was observed between patients with or without 17-OHP hyperresponse to ACTH test (31.1 1.9 vs 24.1 +/- 1.2 mm; p<0.01). No significant changes in the hormonal parameters were observed in the patients, when retested. In conclusion, although none of the patients of the present series exhibited evolution to hypersecretion or to aberrant growth, in more than 40% of patients an increase in the size of the mass was observed, even after a long period of "quiescence". This suggests that a radiological re-evaluation of lesions should be periodically undertaken.

Low basal androstenedione levels plus augmented 17alpha-hydroxyprogesterone and low dehydroepiandrosterone sulfate responses to adrenocorticotropic hormone stimulation in patients with adrenal incidentaloma

OBJECTIVE

To investigate the androstenedione, 17a-hydroxyprogesterone (17-OHP), and dehydroepiandrosterone sulfate (DHEAS) basal levels and responses to adrenocorticotropic hormone (ACTH) in patients with adrenal incidentalomas in order to determine which enzyme defects are present.

METHODS

In a study group of 23 patients (18 women and 5 men who ranged in age from 16 to 70 years) with incidentally discovered asymptomatic adrenal masses, ACTH stimulation was performed to evaluate the secretory responses of 17-OHP and DHEAS. The same test was performed in 15 age- and sex-matched control subjects.

RESULTS

Of the 23 patients, 16 (70%) had a 17-OHP peak >30 nmol/L. The 17-OHP response to ACTH stimulation was significantly higher in patients with adrenal incidentalomas than in control subjects (P<0.001). Fourteen patients had basal DHEAS levels below the 3rd percentile of the control group (1.4 +/- 0.1 mmol/L). The mean stimulated DHEAS level was 1.7 +/- 0.2 mmol/L (range, 0.8 to 4.1) in patients with incidentalomas and 4.2 +/- 0.4 mmol/L (range, 1.8 to 5.6) in the control group (P<0.001). In 13 patients, stimulated DHEAS levels were low in association with high 17-OHP levels. Basal ACTH levels did not differ significantly between patients (8.14 +/- 1.2 pmol/L) and control subjects (8.73 +/- 0.7 pmol/L). Basal androstenedione levels were significantly lower in patients (1.9 +/- 0.3 nmol/L) than in control subjects (5.7 +/- 2.5 nmol/L) (P<0.001). No significant correlation was found between 17-OHP levels and tumor size.

CONCLUSION

Enzyme defects may have an important role in adrenal incidentalomas. Two possible explanations for the observed abnormalities of steroid metabolism in patients with incidentalomas are that (1) the incidentalomas are true primary tumors that have aberrant steroid metabolic pathways or (2) such patients have underlying congenital adrenal hyperplasia that leads, over time, to development of pseudotumors. To assess these two possibilities, we need further studies such as genetic investigations, postoperative test results, and evidence relating the size of the adrenal mass to steroid-suppressible treatment.

Increased serum cortisol levels are associated with high tumour grade in patients with renal cell carcinoma

Cortisol and dehydroepiandrosterone (DHEA) and its sulphate (DHEAS) are the major steroid hormones produced by the human adrenal cortex. The serum levels of cortisol and DHEAS were analysed in 211 consecutive patients with renal cell carcinoma before initiation of therapy. Serum cortisol was significantly higher in patients with renal cell carcinoma compared with that in patients with benign cysts (p < 0.0001). Serum cortisol was independent of disease stage, but positively correlated to tumour diameter and grade. The serum levels of DHEAS were higher in men than in women, and decreased with age, but did not correlate with disease stage, tumour diameter or grade. The prognosis of patients with elevated serum cortisol tended to be poorer (p = 0.06) than the prognosis of those with lower levels. In a multivariate analysis, disease stage and tumour grade were independent predictors of prognosis. Age, gender and serum levels of cortisol and DHEAS were of limited value for prognosis.

Metabolism of glucocorticoids and mineralocorticoids in patients with adrenal incidentalomas

BACKGROUND

Adrenal incidentalomas are mostly nonfunctioning adrenocortical adenomas (NFI). However, in 5%-12% of the patients a preclinical Cushing's syndrome (PCS) with autonomous cortisol production by the tumour is present. Since urinary free cortisol excretion is not sensitive enough to determine subclinical hypercortisolism, in the present study more sensitive indicators of daily cortisol production were measured.

DESIGN

(1) Tetrahydrocortisol, tetrahydrocortisone, urinary free cortisone together with urinary free cortisol were measured in 35 patients with adrenal incidentalomas (29 NFI and six PCS) and in 35 healthy controls. (2) Since little is known about daily aldosterone production, aldosterone metabolite excretions were measured. (3) As recently reported, ACTH stimulation revealed an increased response of precursors of the glucocorticoid and mineralocorticoid pathway. To find out which steroidogenic enzymes have altered activities, a 1-24ACTH stimulation test (250 microg i.v.) was carried out in 25 patients and 18 healthy controls with determination of multiple steroids. (4) Finally, since it was assumed that 21-hydroxylase deficiency or even 11b-hydroxylase deficiency may be involved in adrenal tumourigenesis, the prevalence of germline CYP21B and CYP11B1 mutations were studied in the same patients, who had underwent the ACTH stimulation test.

RESULTS

(1) Glucocorticoid metabolites were within the normal range in all but three patients with NFI. As a group, the patients had subtle alterations in cortisol metabolism. Tetrahydrocortisol excretion was elevated in NFI and PCS compared with normal subjects (2.1 +/- 0.2 and 2.5 +/- 0.5 vs. 1.5 +/- 0.1 mg 24 h(-1); P < 0.05). Accordingly, the twofold elevation of the tetrahydrocortisol/free cortisol ratio indicates an increased 5beta-reduction of cortisol in the liver. (2) Tetrahydroaldosterone and aldosterone-18-glucuronide excretions were not different to controls. (3) In patients with incidentalomas an increased response to ACTH was seen for 17-hydroxyprogesterone (595 +/- 133 vs. 160 +/- 25 ng dL(-1)), 21-desoxycortisol (105 +/- 25 vs. 29 +/- 9 ng dL(-1)) and 11-desoxycortisol (401 +/- 40 vs. 293 +/- 17 ng dL(-1)). (4) In only one of 25 patients, a heterozygous deletion in exon 3 of the CYP21B gene was detected.

CONCLUSIONS

(1) In conclusion, even the excretion of the main glucocorticoid metabolites is not a marker sensitive enough to distinguish between NFI and PCS. However, it is also possible that alterations in cortisol secretion are qualitative rather than quantitative. (2) Zona glomerulosa function is not influenced. (3) The elevation of 21-desoxycortisol argues against an impairment of 11beta-hydroxylase and favours a decreased activity of 21-hydroxylase. All others had wild-type sequences of both genes. (4) In conclusion, neither 21-hydroxylase deficiency nor 11beta-hydroxylase deficiency are predisposing factors for adrenal tumourigenesis.

Adrenal bilateral incidentaloma by reactivated histoplasmosis

We report a case of bilateral adrenal incidentaloma caused by the capsulatum variety of Histoplasma capsulatum diagnosed in a 74 years old man born in and a life time resident of Treviso, Italy, with the exception of two years spent in Pakistan (1964-1966) as a well-driller. The patient was hospitalized in 1995 for alcoholic chronic hepatitis, chronic Helicobacter pylori gastritis and post-infarction ischemic cardiomyopathy. Abdominal ultrasound incidentally showed bilateral adrenal masses (the right one 6.3 cm in diameter) confirmed by computed tomography, with adrenal function within normal limits. After three months, the patient was again hospitalized due to evening fever, asthenia, anorexia, weight loss and occasional hyperhidrosis. Abdominal ultrasound showed an increase of the right adrenal lesion with normal adrenal function. Ultrasound-guided fine needle aspiration did not prove useful for diagnosis. Accordingly, a laparotomy with bilateral biopsy was performed; histology showed the presence of numerous tissue form cells of H. capsulatum variety capsulatum. Serum anti-H. capsulatum antibodies were negative. Since March, 1996, the patient was given itraconazole and his symptoms quickly regressed but the computed tomography findings, however, have not changed and the patient has adrenal hypofunction that is being treated with cortisone acetate.

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.

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

OBJECTIVE

It has recently been suggested that autonomous cortisol production may lead to subclinical glucocorticoid excess in a substantial number of patients with incidentally discovered adrenocortical adenomas. Following a standard low-dose dexamethasone suppression test (LDDST) cortisol concentrations are frequently incompletely suppressed in patients with adrenal incidentalomas, due to an ACTH-independent secretion of cortisol by the adrenal mass. Thus, post LDDST cortisol concentrations may provide a measure of the degree of autonomous glucocorticoid secretion, but hormonal alterations in relation to post-LDDST cortisol concentrations have not been thoroughly investigated.

PATIENTS AND MEASUREMENTS

61 patients with radiological features highly suggestive of adrenal adenomas were studied. These included 43 women, 18 men; mean age 59 +/- 1.4, range: 25-76 years; BMI 30.9 +/- 0.8 kg/m2 and waist:hip ratio 0.90 +/- 0.016. All subjects underwent a standard LDDST, as follows: after a 48-hr stabilisation period, 24-hr urine collections for basal urinary free cortisol (UFC) were performed. Basal serum cortisol and plasma ACTH were measured at 8 AM and at midnight the following day, and subjects started dexamethasone 0.5 mg 6 hourly for 2 days. Post-dexamethasone cortisol and ACTH levels were measured at 8 AM, 6-hrs after the last dose of dexamethasone. Blood samples for dehydroepiandrosterone sulphate (DHEAS) and serum lipids were obtained on the morning preceding dexamethasone administration.

RESULTS

Post-LDDST cortisol concentrations correlated positively with the size of the adenoma (r = +0.527, P < 0.001). There was a negative rank correlation of post-LDDST cortisol concentrations and basal ACTH levels at 0900 h (rs = -0.426, P < 0.001) and DHEAS (rs = -0.380, P = 0.006). Moreover, there was a good rank correlation between DHEAS and basal ACTH levels (rs = +0.456, P < 0.001). A positive rank correlation was observed between post-LDDST cortisol concentrations and midnight cortisol concentrations (rs = +0.317, P = 0.020). As recent studies have suggested that post-LDDST cortisol levels higher than 70 nmol/l may indicate significant hypercortisolism comparisons were also performed between patients divided according to post-LDDST cortisol values into 3 groups: Group A, > 70 nmol/l (19 pts); Group B, 30-70 nmol/l (27 pts); Group C, < 30 nmol/l (15 pts). Although there was no difference in basal cortisol and UFC values between these groups, ACTH and DHEAS levels were significantly lower, and midnight cortisol significantly higher in group A compared to group C patients (P = 0.030, P = 0.017 and P = 0.001 respectively). Cholesterol and triglyceride levels were slightly albeit significantly higher in group A compared to group C patients (P < 0.05).

CONCLUSIONS

It is concluded that higher post-low dose dexamethasone cortisol concentrations are associated with lower ACTH and dehydroepiandrosterone sulphate, higher midnight cortisol concentrations and larger adenomas. These findings are consistent with the hypothesis that post-low dose dexamethasone cortisol concentrations represent a useful index in assessing subtle glucocorticoid autonomy in patients with adrenal adenomas.

Utility of plasma dehydroepiandrosterone sulphate determination in adrenal incidentalomas

To evaluate whether low DHEA-S levels are predictors of cortical origin, benignity and hormonal activity in incidentally detected adrenal masses, thirty-five patients with adrenal incidentalomas were studied. All patients were operated on and the diagnosis was histologically confirmed. Basal endocrine workup included plasma determination of cortisol before and after dexamethasone (1 mg overnight), plasma ACTH (08:00 h), 17-OH-progesterone, testosterone and potassium, standing plasma renin activity and aldosterone, supine and standing plasma noradrenaline and adrenaline. If necessary, we performed dexamethasone suppression tests at low (2 mg) and high (8 mg) doses, or the loperamide test (16 mg os) for evaluation of glucocorticoid activity and the glucagon test (1 mg i.v.) for exploring adrenal medulla function. Plasma DHEA-S was measured in all patients and the results were compared to those obtained in controls matched for age, sex and menopausal status. Suppression of DHEA-S was found in 11 out of 35 patients (31.5%). However, this hormonal finding occurred in 50% of the extracortical adrenal lesions, while in proven cortical adenomas (no. = 19) it was detected in only 5 patients (26.3%). Sensitivity, specificity, diagnostic accuracy and positive predictive value of low DHEA-S in indicating a cortical origin of the mass were 0.27, 0.0, 0.25, and 0.80. In malignancies (no. = 6) low DHEA-S levels were found in 1 out of 2 metastases and never in cortical carcinomas. Sensitivity, specificity, diagnostic accuracy and positive predictive value of low DHEA-S in indicating a benign form were 0.34, 0.83, 0.42, and 0.91. Six out of 19 patients with cortical adenomas showed signs of hypothalamic-pituitary adrenal (HPA)-axis dysfunction. Low DHEA-S levels were found in 50% of adenomas with HPA-axis abnormality and in 15.3% of adenomas without hormonal activity. Sensitivity, specificity, diagnostic accuracy, and positive predictive value of low DHEA-S levels in indicating hormonal activity of the mass were 0.50, 0.84, 0.73, and 0.60. Our data indicate that the association between low DHEA-S levels and adrenal incidentalomas is frequent. Low DHEA-S appears to be a poor predictor of hormonal activity with low sensitivity and specificity in respect of cortical origin and benignity of the mass. In conclusion, our results show that DHEA-S measurement does not offer relevant clinical information in the management of adrenal incidentalomas.

The low-dose dexamethasone suppression test in patients with adrenal incidentalomas: comparisons with clinically euadrenal subjects and patients with Cushing's syndrome

OBJECTIVE

Increasing evidence favours subtle glucocorticoid excess in many patients with adrenal incidentalomas. However, existing evidence is based mainly on the overnight dexamethasone suppression test, a test that is commonly abnormal even among clinically euadrenal subjects. The aim of the present study was to evaluate patients with adrenal incidentalomas for subtle glucocorticoid excess by the more specific low-dose dexamethasone test (LDDST). Moreover, since the criteria of what constitutes an abnormal cortisol response following this test have been largely anecdotal, we report our results in comparison with those obtained in clinically euadrenal subjects, and patients with Cushing's syndrome.

DESIGN

A prospective study of 57 patients with adrenal incidentalomas with CT characteristics highly suggestive of benign adrenocortical adenomas and 85 clinically euadrenal subjects consisting of 54 obese women with BMI > 30 kg/m2 (range 30-54.7), 13 women with BMI < 30 kg/m2 (range 20.3-29.6) and 18 healthy volunteers (10 women and eight men) over 40 years of age (mean age 51.7 +/- 9.9, range 40-74; mean BMI 30 +/- 6.6, range 20.3-47.5 kg/m2). A retrospective analysis was performed on 60 patients with a confirmed diagnosis of Cushing's syndrome.

MEASUREMENTS

All subjects were admitted to the endocrine ward and underwent a standard LDDST, as follows: after a 48-h stabilization period, a 24-h urine collection for basal urinary free cortisol was performed. Basal serum cortisol and plasma ACTH were measured at 0800 h the following day, and subjects were started on dexamethasone 0.5 mg 6-hourly for 2 days. Post-dexamethasone cortisol and ACTH levels were measured at 0800 h, 6 h after the last dose of dexamethasone.

RESULTS

Following dexamethasone suppression serum cortisol concentrations became undetectable (< 28 nmol/l) in all clinically euadrenal subjects. In patients with incidentally discovered adrenal masses, post-LDDST cortisol concentrations were undetectable in 12 (21%), between 28-140 nmol/l in 38 (67%), and 140-216 nmol/l in seven (12%) patients; post-LDDST cortisol values correlated positively with the size of the adenoma (r = +0.482, P < 0.001). Post-LDDST cortisol concentrations in patients with Cushing's syndrome ranged from 85 to 1786 nmol/l; in 3/42 (7%) patients with ACTH-dependent Cushing's syndrome cortisol concentrations were < 140 nmol/l.

CONCLUSIONS

On the basis of our data in a large group of clinically euadrenal subjects, we suggest that following LDDST cortisol concentrations should become undetectable with the currently used radioimmunoassays. In patients with adrenal incidentalomas, application of the LDDST confirmed the presence of incomplete suppression of cortisol in the majority of patients. We suggest that the LDDST is a sensitive index of autonomous cortisol production in patients with adrenal incidentalomas; following this test a grading of subtle glucocorticoid excess may be obtained but future studies correlating biochemical, clinical and epidemiological data are required, in order to develop widely agreed cut-off levels of clinically significant glucocorticoid excess in these patients.

Subclinical Cushing's syndrome in adrenal incidentaloma

OBJECTIVE

Some patients with incidentally discovered adrenal adenomas display autonomous cortisol secretion not fully restrained by pituitary feedback, a condition that may be defined as subclinical Cushing's syndrome. We have evaluated the presence of subclinical Cushing's syndrome and its natural history in a cohort of patients with incidentally discovered adrenal adenomas.

PATIENTS

Fifty-three consecutive patients (30 women and 23 men; median age 58 years, range 18-81 years) were studied. Diagnostic procedures were initiated for extra-adrenal complaints. Patients with known extra-adrenal malignancies or patients with hypertension of possible endocrine origin were excluded.

MEASUREMENTS

All patients underwent the following endocrine evaluation: (1) measurement of DHEA-S at 0800 h, (2) measurement of serum cortisol at 0800 and 2400 h, (3) measurement of the 24-h excretion of urinary free cortisol (UFC), (4) overnight low-dose dexamethasone suppression test, (5) measurement of plasma ACTH at 0800 h (mean of at least two samples on different days), (6) oCRH stimulation test. Different groups of healthy subjects recruited from the hospital medical staff and their relatives served as controls for the various tests. The same endocrine work-up was repeated after 12 months in 25 patients. All patients were followed up at regular intervals for at least 12 months with clinical examination and abdominal computed tomography. Subclinical hypercortisolism was arbitrarily defined as definitive, probable or possible, according to the degree of endocrine abnormalities.

RESULTS

UFC was significantly higher in patients with incidentaloma than in controls (262, 25-690 nmol/24 h versus 165, 25-772 nmol/24 h; P = 0.012). The percentage of subjects who did not suppress on dexamethasone was greater among patients than among healthy subjects (9/53 (17%) versus 5/103 (5%), P = 0.026). Plasma ACTH concentrations were lower in patients with adrenal incidentaloma than in controls (3, 1-9 pmol/l versus 5, 1-14 pmol/l; P = 0.014). These findings consistently point toward a functional autonomy of the adrenal adenomas even if the degree of cortisol excess is mild. Three patients fulfilled the criteria for definitive subclinical hypercortisolism, five for probable and two possible, but none of them experienced clinical and/or biochemical progression to overt hypercortisolism after 12 months. During follow-up, no signs of extra-adrenal malignancy became manifest and the size of the mass did not increase significantly in any patient.

CONCLUSIONS

This study provides a clear demonstration of the current opinion that some patients with incidentally discovered adrenal adenomas may be exposed to a subtle, silent hypercortisolism. In some patients, in whom the clustering of more abnormalities in the hypothalamo-pituitary-adrenal axis occurs, subclinical Cushing's syndrome could be assumed. This term should be preferred to that of pre-clinical Cushing's syndrome since the biochemical abnormalities do not become clinically manifest, at least in the short term.

Adrenal incidentalomas. Diagnostic workup of the incidentally discovered adrenal mass

The incidentally discovered adrenal mass is a diagnostic dilemma veterinarians are likely to face with increasing frequency in the coming years. Dogs and cats may be more prone to functional adrenal lesions than are humans. Most adrenal tumors are benign, but a significant number of adrenocortical carcinomas (approximately 12%) and metastatic lesions within the adrenal glands (3% to 34%) do occur. Evaluation for hypertension, hypokalemia, and loss of hypothalamic-pituitary-adrenal responsiveness to a low dose of dexamethasone is appropriate for all patients with adrenal incidentalomas. The value of clinical and historical signs of hormonal overexpression should not be underestimated. More invasive or expensive diagnostic testing should be predicted on suspicions raised by the history and clinical signs. New diagnostic clinicopathologic tests, including plasma CgA and serum DHEAS, should be investigated in veterinary patients. Advanced diagnostic imaging using nuclear scintigraphy and chemical-shift MRI may offer veterinarians sensitive and specific noninvasive tools to consider for the evaluation of these patients. Patients with large masses, tumors with signs of malignancy, or productive adrenal tumors (plus or minus cortisol-producing tumors in which chemical ablation with mitotane can be attempted) should be considered candidates for exploratory surgery.

Evaluation of hormonal function in a series of incidentally discovered adrenal masses

The discovery of an asymptomatic adrenal mass (incidentaloma) during the investigation of an unrelated condition is relatively common. In this study, we report the clinical, radiologic, and endocrine evaluation of 38 patients (22 women and 16 men aged 24 to 84 years) with adrenal incidentaloma (size, 1 to 12 cm). The patients underwent basal and dynamic evaluation of the hypothalamic-pituitary-adrenal (HPA) axis, renin-angiotensin-aldosterone system, and adrenomedullary function. Moreover, computed tomograpy (CT) scan and 131I-6beta-iodomethyl-19-norcholest-5(10)-en-3beta-ol(NP-59) and/or 131I-metaiodobenzylguanidine (MIBG) scintigraphy were performed. The endocrine evaluation indicated two cases of pheochromocytoma and four cases of preclinical Cushing's syndrome, three of which underwent surgery with histologic diagnosis of two adrenocortical adenomas and one carcinoma. Low levels of serum dehydroepiandrosterone sulfate (DHEA-S), associated with a markedly increased 17-hydroxyprogesterone (17-OHP) response to a corticotropin (ACTH) test, were found in patients with incidentaloma. On the basis of endocrine and morphologic data, 13 patients underwent surgical treatment: five adrenocortical adenomas (two functioning), two pheochromocytomas, two ganglioneuromas, one cortisol-secreting adrenal carcinoma, one lymphangiomatous cyst, one myelolipoma, and one hemorrhage were found. Careful diagnostic assessment of incidentally discovered adrenal masses must be performed to exclude the presence of malignant and/or functioning lesions and to verify the possibility that patients with incidentaloma have a genetic or acquired deficit of adrenal steroidogenic activity.

An unusual case of bilateral virilizing adrenal adenoma co-secreting androgens and cortisol

We report the case of a 68-year-old woman presenting with clinical and biochemical evidence of hyperandrogenism. Imaging studies revealed the presence of a bilateral adrenal tumor. Although there was a predominant secretion of androgens, autonomous production of cortisol was also evidenced on the basis of an inversion of the circadian rhythm of plasma cortisol and an absence of cortisol suppression by dexamethasone. The functional status of both tumors was demonstrated by an iodocholesterol scintigraphy and by an adrenal vein catheterization. Surgical excision of both adrenal tumors was performed and histological examination disclosed no criteria of malignancy. The patient still remains disease-free 3 years after surgery. To our knowledge, this is the second report of the bilateral occurrence of a virilizing adrenal tumor and the first in which the functional characteristics of the tumors are detailed.

Partially autonomous cortisol secretion by incidentally discovered adrenal adenomas

Recent studies of the function of adrenal "incidentalomas" have revealed that a proportion of those tumors secrete cortisol insufficiently to produce overt clinical Cushing s syndrome, but that their autonomous cortisol production can suppress the hypothalamo-pituitaryadrenal (HPA) axis to various degrees; this needs to be recognized to avoid acute adrenal insufficiency after adrenalectomy. Several diagnostic approaches have been utilized to identify the partially autonomous cortisol-secreting adenomas. It has been suggested that a lack of normal suppression of cortisol (> 140 nmol/L) on the morning after 1-mg oral dexamethasone at bedtime would identify most functional autonomous cortisol-secreting tumors. Based on this criterion, approximately 18% of published cases of incidentalomas would secrete cortisol autonomously. However, other tests indicating alterations of the HPA axis, such as abnormal adrenal iodocholesterol uptake or decreased plasma levels of dehydroepiandrosterone sulfate (DHAS), were found to be present in up to 79%-86% of incidentalomas. This is illustrated by the description of three patients with incidentalomas with plasma cortisol levels < 140 nmol/L in 2 of 3 patients after 1-mg dexamethasone overnight; however, various degrees of HPA axis suppression were demonstrated by an i.v. dexamethasone (4-mg) suppression test, decreased plasma DHAS levels and unilateral adrenal iodocholesterol uptake. After laparoscopic adrenalectomy, the response of plasma cortisol to 250 mug i.v. of ACTH (1-24) was subnormal in 2 of 3 patients and was restored to normal within 2 months. We conclude that the criterion of a plasma cortisol level > 140 nmol/L, after an overnight 1-mg dexamethasone suppression test, underestimates the incidence of partially autonomous cortisol-secreting adrenal adenomas. The literature on this subject is reviewed, and recommendations for evaluation and treatment are presented.