Adrenal incidentalomas are adrenal masses detected on imaging performed for reasons other than suspected adrenal disease. In most cases, adrenal incidentalomas are non-functioning adrenocortical adenomas, but may also require therapeutic intervention including that for adrenocortical carcinoma, pheochromocytoma, hormone-producing adenoma or metastases. Here, we provide a revision of the first international, interdisciplinary guidelines on incidentalomas. We followed the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system and updated systematic reviews on four predefined clinical questions crucial for the management of incidentalomas: A) How to assess risk of malignancy? ; B) How to define and manage mild autonomous cortisol secretion? ; C) Who should have surgical treatment and how should it be performed? ; D) What follow-up is indicated if the adrenal incidentaloma is not surgically removed? Selected Recommendations: 1) Each adrenal mass requires dedicated adrenal imaging. Recent advances now allow discrimination between risk categories: Homogeneous lesions with HU ≤ 10 on unenhanced CT are benign and do not require any additional imaging independent of size. All other patients should be discussed in a multidisciplinary expert meeting, but only lesions >4 cm that are inhomogeneous or have HU >20 have sufficiently high risk of malignancy that surgery will be the usual management of choice. 2) Every patient needs a thorough clinical and endocrine work-up to exclude hormone excess including the measurement of plasma or urinary metanephrines and a 1-mg overnight dexamethasone suppression test (applying a cutoff value of serum cortisol ≤50 nmol/l (≤1.8 µg/dl)). Recent studies have provided evidence that most patients without clinical signs of overt Cushing's syndrome but serum cortisol levels post dexamethasone >50 nmol/l (>1.8 µg/dl) harbor increased risk of morbidity and mortality. For this condition, we propose the term ‘mild autonomous cortisol secretion’ (MACS). 3) All patients with MACS should be screened for potential cortisol-related comorbidities that are potentially attributably to cortisol (e.g. hypertension and type 2 diabetes mellitus), to ensure these are appropriately treated. 4) In patients with MACS who also have relevant comorbidities surgical treatment should be considered in an individualized approach. 5) The appropriateness of surgical intervention should be guided by the likelihood of malignancy, the presence and degree of hormone excess, age, general health and patient preference. We provide guidance on which surgical approach should be considered for adrenal masses with radiological findings suspicious of malignancy. 6) Surgery is not usually indicated in patients with an asymptomatic, non-functioning unilateral adrenal mass and obvious benign features on imaging studies. Furthermore, we offer recommendations for the follow-up of non-operated patients, management of patients with bilateral incidentalomas, for patients with extra-adrenal malignancy and adrenal masses, and for young and elderly patients with adrenal incidentalomas. Finally, we suggest ten important research questions for the future.
Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment. We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival. For first-line therapy, patients in the EDP–mitotane group had a significantly higher response rate than those in the streptozocin–mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP–mitotane group and 2.2 months in the streptozocin–mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments. Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival. (Funded by the Swedish Research Council and others; FIRM-ACT ClinicalTrials.gov number, NCT00094497.)
Adrenocortical carcinoma is a rare neoplasm characterized by a high risk of recurrence after radical resection. Whether the use of mitotane is beneficial as an adjuvant treatment has been controversial. Our aim was to evaluate the efficacy of adjuvant mitotane in prolonging recurrence-free survival. We performed a retrospective analysis involving 177 patients with adrenocortical cancer who had undergone radical surgery at 8 centers in Italy and 47 centers in Germany between 1985 and 2005. Adjuvant mitotane was administered to 47 Italian patients after radical surgery (mitotane group), whereas 55 Italian patients and 75 German patients (control groups 1 and 2, respectively) did not receive adjuvant treatment after surgery. Baseline features in the mitotane group and the control group from Italy were similar; the German patients were significantly older (P=0.03) and had more stage I or II adrenocortical carcinomas (P=0.02) than did patients in the mitotane group. Recurrence-free survival was significantly prolonged in the mitotane group, as compared with the two control groups (median recurrence-free survival, 42 months, as compared with 10 months in control group 1 and 25 months in control group 2). Hazard ratios for recurrence were 2.91 (95% confidence interval [CI], 1.77 to 4.78; P<0.001) and 1.97 (95% CI, 1.21 to 3.20; P=0.005), respectively. Multivariate analysis indicated that mitotane treatment had a significant advantage for recurrence-free survival. Adverse events associated with mitotane were mainly of grade 1 or 2, but temporary dose reduction was needed in 13% of patients. Adjuvant mitotane may prolong recurrence-free survival in patients with radically resected adrenocortical carcinoma.
Objective: To assess currently available evidence on adrenal incidentaloma and provide recommendations for clinical practice.Design: A panel of experts (appointed by the Italian Association of Clinical Endocrinologists (AME)) appraised the methodological quality of the relevant studies, summarized their results, and discussed the evidence reports to find consensus.Radiological assessment: Unenhanced computed tomography (CT) is recommended as the initial test with the use of an attenuation value of ≤10 Hounsfield units (HU) to differentiate between adenomas and non-adenomas. For tumors with a higher baseline attenuation value, we suggest considering delayed contrast-enhanced CT studies. Positron emission tomography (PET) or PET/CT should be considered when CT is inconclusive, whereas fine needle aspiration biopsy may be used only in selected cases suspicious of metastases (after biochemical exclusion of pheochromocytoma).Hormonal assessment: Pheochromocytoma and excessive overt cortisol should be ruled out in all patients, whereas primary aldosteronism has to be considered in hypertensive and/or hypokalemic patients. The 1 mg overnight dexamethasone suppression test is the test recommended for screening of subclinical Cushing's syndrome (SCS) with a threshold at 138 nmol/l for considering this condition. A value of 50 nmol/l virtually excludes SCS with an area of uncertainty between 50 and 138 nmol/l.Management: Surgery is recommended for masses with suspicious radiological aspects and masses causing overt catecholamine or steroid excess. Data are insufficient to make firm recommendations for or against surgery in patients with SCS. However, adrenalectomy may be considered when an adequate medical therapy does not reach the treatment goals of associated diseases potentially linked to hypercortisolism.