Image of adrenal mass

Axial computed tomographic image of an asymptomatic patient with an incidentally discovered 2.5-cm left adrenal mass (arrow). This mass has an imaging phenotype consistent with a cortical adenoma: It is hypodense, not vascular, and homogeneous. The Hounsfield unit density before contrast medium administration was –5. Ten minutes after administration, there was 70% contrast washout.