Follow-up imaging of benign-appearing incidental adrenal masses is unnecessary

If adrenal masses are found incidentally during a CT scan, and the masses look benign, they do not require additional imaging follow-up, according to a recent study conducted by researchers at Brown University in Providence, Rhode Island.

“With increased utilization of CT, we are frequently encountering findings that are not related to why the patients were scanned, the so called ‘incidentalomas,’ of which adrenal masses are quite common,” said Julie Song, MD, lead author of the study. “On one hand, radiologists have made tremendous progress in evaluating adrenal mass with high accuracy, but on the other hand it is unclear whether every adrenal mass discovered has to undergo rigorous work up,” said Dr. Song. “There has been little consensus among different disciplines and even among radiologists about how to manage these incidental masses found on the CT scans, and that uncertainty was the impetus for conducting this study,” she said.

The study included 290 patients with 321 indeterminate, but benign-appearing adrenal lesions found during the CT examination. According to the study, 318 of the 321 masses were confirmed (based on histopathology, additional imaging studies and/or clinical follow-up) to be benign and clinically insignificant. There were three clinically unsuspected functioning masses: one cortisol-producing adenoma and two pheochromocytomas. The study showed no metastatic adrenal lesions, even among the 13 patients who developed malignancy elsewhere.

“Our study showed none of these incidentally detected adrenal masses were malignant in our low-risk population and follow-up imaging work up appears to have a limited role,” said Dr. Song. “One of the surprises from our study was how few adrenal masses required biopsy (2%) for diagnosis; I think that is a testament to the success and acceptance of imaging to be highly accurate in diagnosing adrenal masses,” she said.

The full results of this study appear in the November issue of the American Journal of Roentgenology, published by the American Roentgen Ray Society.