Imaging the non-hyperfunctioning adrenal mass

Abstract

Adrenal masses occur in 9% of the population and their detection has increased with the expanding use of cross-sectional imaging. The objective in working-up the incidental non-hyperfunctioning adrenal mass is to distinguish benign from malignant lesions. Tumours larger than 5 cm are likely to be malignant and should be biopsied or excised. Adrenal masses with an unenhanced CT density ≤10 HU, or signal drop off on chemical shift MRI, are benign. Tumours that commonly metastasise to the adrenal gland include bronchogenic carcinoma, breast carcinoma and melanoma, with small cell lung carcinoma accounting for 6% of adrenal metastases.