Clinically silent adrenal masses discovered by imaging studies performed for unrelated reasons, i.e. adrenal incidentalomas, have become a rather common finding in clinical practice. However, only limited studies of incidence, prevalence, and natural history of adrenal incidentalomas are available. A comprehensive review of the literature shows the prevalence of adrenal incidentalomas to be 2.3% at autopsy and 0.5-2% at abdominal computed tomography scan. Most lesions are adrenocortical adenomas at histology, whereas the prevalence of adrenocortical carcinomas is relatively low. The risk of malignancy over time for masses defined as benign at diagnosis is estimated at about 1/1000, even though 5-25% of masses increase in size during follow-up. Hyperfunction develops in about 1.7% of cases and the risk is higher in patients with lesions larger than 3 cm. Cortisol hypersecretion is the most likely disorder that may ensue, and it remains subclinical in about two-thirds of cases. The lack of controlled studies precludes making specific management recommendations. Large perspective controlled studies to define the epidemiology, natural history, and possible associated morbidity of adrenal incidentalomas and their impact on the quality of life of patients are needed.

Patients with hypertension have a high prevalence of concurrent metabolic abnormalities, including obesity, dyslipidemia, and hyperglycemia. Clustering of these cardiovascular risk factors, defined as metabolic syndrome, causes a more pronounced target organ damage. Aldosterone excess has been found to be associated with glucose disorders and may contribute to cardiovascular damage. The aim of our study was to assess the prevalence and the characteristics of the metabolic syndrome in a group of patients with hypertension due to primary aldosteronism compared with patients with essential hypertension. The National Cholesterol Education Program Adult Treatment Panel III definition of the metabolic syndrome was used. Eighty-five patients with primary aldosteronism and 381 patients with essential hypertension were studied. Most patients were not receiving antihypertensive therapy during the investigation. Blood glucose and systolic blood pressure were higher (P < 0.05 and P < 0.01, respectively) and duration of hypertension was longer (P < 0.05) in primary aldosteronism than in essential hypertension. The prevalence of metabolic syndrome was higher in primary aldosteronism than in essential hypertension (41.1% vs. 29.6%; P < 0.05). Distribution of single components of the metabolic syndrome other than hypertension showed a higher prevalence of hyperglycemia in primary aldosteronism than in essential hypertension (27.0% vs. 15.2%; P < 0.05). Our findings confirm a negative effect of aldosterone excess on glucose metabolism and suggest that the recently reported higher rates of cardiovascular events in primary aldosteronism than in essential hypertension might be due to increased prevalence of the metabolic syndrome in the former condition.

Primary aldosteronism is the most common form of secondary hypertension. Somatic mutations in KCNJ5 , ATP1A1 , ATP2B3 , and CACNA1D have been described in aldosterone-producing adenomas (APAs). Our aim was to investigate the prevalence of somatic mutations in these genes in unselected patients with APA (n=474), collected through the European Network for the Study of Adrenal Tumors. Correlations with clinical and biochemical parameters were first analyzed in a subset of 199 patients from a single center and then replicated in 2 additional centers. Somatic heterozygous KCNJ5 mutations were present in 38% (180/474) of APAs, whereas ATP1A1 mutations were found in 5.3% (25/474) and ATP2B3 mutations in 1.7% (8/474) of APAs. Previously reported somatic CACNA1D mutations as well as 10 novel CACNA1D mutations were identified in 44 of 474 (9.3%) APAs. There was no difference in the cellular composition of APAs or in CYP11B2 , CYP11B1, KCNJ5 , CACNA1D , or ATP1A1 gene expression in APAs across genotypes. Patients with KCNJ5 mutations were more frequently female, diagnosed younger, and with higher minimal plasma potassium concentrations compared with CACNA1D mutation carriers or noncarriers. CACNA1D mutations were associated with smaller adenomas. These associations were largely dependent on the population structure of the different centers. In conclusion, recurrent somatic mutations were identified in 54% of APAs. Young women with APAs are more likely to be KCNJ5 mutation carriers; identification of specific characteristics or surrogate biomarkers of mutation status may lead to targeted treatment options.