Imaging Assessment

This algorithm assumes there is no prior history of a known other cancer (and therefore the lesion is unlikely to represent a metastasis, see below).

Following this simplified algorithm will provide care which is in line with the Canadian Urological Association 2023 guidelines (endorsed by the American Urological Association), with only small differences from the American College of Radiology white paper and European Society of Endocrinology guidelines.

Benign masses here require no further imaging. (Though they still require a hormonal workup.)

Follow here would reasonably mean repeat imaging in 6 months. Performance and interpretation of follow up is more nuanced, so non-urgent referral to an expert center is reasonable.

For patients requiring further workup or surgery, we recommend timely referral to an expert center. These patients either are high risk for adrenocortical carcinoma (e.g. masses >6cm and >20 HU on non-contrast imaging) and therefore should be managed by experts, or they require further testing/interpretation which requires a more detailed understanding of the literature than is provided by guidelines.

If there is a history of other malignancy

Consider PET/CT or biopsy (after hormonal workup) if imaging workup is equivocal. Metastases from kidney or liver may have washout characteristics similar to adenoma.

Adrenal CT Washout Studies

Consensus on the diagnostic utility of these studies is poor, so referral to expert centers prior to ordering/interpreting these studies may be warranted.

If necessary, adrenal protocol CT is performed in 3 stages:

1. non-contrast

2. contrast enhanced (60-90 seconds after contrast administration)

3. delayed (15 minutes after contrast administration)

If the lesion is <10 HU on the non-contrast phase, the exam should be stopped. The lesion is almost certainly a benign adenoma and washout studies are not informative.

If the lesion does not enhance (<10 HU increase after contrast administration), the lesion is benign and washout should not be calculated.

Online washout % calculator