CT Detected Silent Adrenal Tumors Need Follow-Up

Tumors of the adrenal gland that were incidentally detected by CT scan in asymptomatic people may become more active and increase risk of cardiovascular events, according to a study published in The Lancet Diabetes & Endocrinology.

An estimated 4 percent of CT scans not performed for suspicion of an adrenal gland tumor will uncover one. However, until now, evidence on how to manage these “silent” tumors has been lacking. While their discovery is increasing with more use of CT scans, how or whether these tumors should be treated has remained uncertain.

To address this issue, researchers in Italy undertook a study to determine the frequency of new cardiovascular events and mortality in patients with non-secreting adrenal incidentalomas, tumors of intermediate phenotype, or those causing subclinical Cushing’s syndrome.

“Our findings are important because they add to the previously scant information about adrenal incidentalomas, which will be of use to doctors who are seeing an increasing number of patients with these masses,” lead author Professor Renato Pasquali, said in a release. Pasquali is from the S Orsola-Malpighi Hospital, in Bologna.

A total of 198 outpatients with adrenal incidentalomas, referred from January 1995 to September 2010, were included in the study. The patients were assessed every 18 to 30 months for the first five years of enrollment (mean follow-up: 7.5 years). The researchers used cortisol concentrations after the 1 mg dexamethasone suppression test (DST) to define non-secreting (<50 nmol/L) and intermediate phenotype (50–138 nmol/L) adrenal incidentalomas and subclinical Cushing’s syndrome (>138 nmol/L). At the end of follow-up, patients were reclassified as having either unchanged or worsened secreting patterns from baseline.

At the end of follow-up, 114 patients had stable non-secreting adrenal incidentalomas, 61 had either a stable intermediate phenotype or subclinical Cushing’s syndrome, and 23 had a pattern of secretion that had worsened. The incidence of cardiovascular events was higher among patients with stable intermediate phenotype or subclinical Cushing’s syndrome

Patients with stable non-secreting adrenal incidentalomas did not have as high an incidence of cardiovascular events as did those with who had a stable intermediate phenotype or subclinical Cushing’s syndrome (6.7 percent versus 16.7 percent) and, as well as those with worsened secreting patterns (6.7 percent versus 28.4 percent). Cardiovascular events were associated independently with a change in cortisol concentrations after DST.

“Survival rates for all-cause mortality were lower in patients with either stable intermediate phenotype adrenal incidentalomas or subclinical Cushing’s syndrome compared with those with stable non-secreting masses (57.0 percent versus 91.2 percent),” the authors wrote.

Commenting on the findings, Professor Rosario Pivonello, of the Università Federico II in Naples, said, “The study findings underline that the degree of hormonal dysfunction can worsen during follow-up…[and] support the importance of long-term hormonal follow-up for clinical management of all patients with adrenal incidentalomas. Furthermore, clinical monitoring of cardiometabolic risks seems to be important in these patients, particularly in those with [secreting tumors], for whom medical or surgical intervention could be needed.”