Adrenal Gland Masses Mostly Benign, New Zealand Study Suggests

The prevalence in New Zealand of adrenal incidentalomas, which are masses in the adrenal glands incidentally discovered during an imaging test, is similar to that of international centers, a new study found. This means that current international guidelines for managing adrenal incidentalomas likely should be applied to patients in New Zealand as well, the study’s authors concluded.

The study, “Characteristics of adrenal incidentalomas in a New Zealand centre,” appeared in the Internal Medicine Journal.

Several international studies suggest that adrenal incidentalomas (AI) are mostly non-functional, benign masses that require no treatment. But in some cases, adrenal incidentalomas may be malignant and produce excess hormones.

In the past, guidelines for the management of adrenal incidentalomas involved significant investigation and follow-up. But that entailed costly, and mostly unnecessary, tests.

Therefore, “guidelines have evolved to a more conservative approach,” the researchers wrote, particularly if a tumor is thought to be benign and does not produce excess hormones.

To determine whether the international guidelines are applicable for New Zealand’s population, researchers examined the clinical characteristics of patients with adrenal incidentalomas at a tertiary care center in Canterbury.

The study included 228 patients 18 and older who were diagnosed between January 2010 and April 2016. The masses were checked for malignancy using computerized tomography (CT) scans. Other parameters, including medical history, blood and urine biochemical tests, and individual body measurements were collected.

Abdominal pain was the most common cause (46%) for imaging tests that led to the discovery of adrenal incidentalomas. Of the adrenal incidentalomas examined, 95% were characterized as benign, and 88.6% of all cases were categorized as non-functional, meaning excess hormones were not produced.

Among the 26 patients with functioning tumors — meaning their tumors produced high levels of at least one adrenal hormone — 18 had subclinical Cushing’s syndrome characterized by excess production of cortisol. Three patients had primary adrenal cancer, one of whom was secreting excess cortisol.

Overall, these results showed a similar prevalence of functional and malignant adrenal incidentalomas in New Zealand as seen in other international studies.

“The conservative approach to management of AI recommended in current guidelines is likely to be applicable to New Zealand population,” the study concluded.

Researchers are now conducting a follow-up study to further assess the outcomes of these patients.