Which feature most strongly suggests a malignant adrenal mass?

Which feature most strongly suggests a malignant adrenal mass?

• A. Lipid-rich appearance
• B. Size greater than 6 cm
• C. Normal hormonal function
• D. Smooth borders

Answer: (B)

The most important clue that a adrenal mass is malignant is its size. A mass larger than about 6 cm carries a significantly higher risk of cancer, so this size threshold is a strong predictor and often prompts surgical removal. Imaging features that suggest benign disease, like a lipid-rich appearance on CT or MRI, point toward an adrenal adenoma because benign adenomas typically contain intracellular lipid that lowers radiodensity. Normal hormonal function indicates the mass isn’t secreting excess adrenal hormones, but many malignant lesions can be nonfunctional, so normal function doesn’t reliably rule out cancer. Border characteristics can help, but they’re less definitive than size—malignant tumors often have irregular or infiltrative borders, yet a large size remains the strongest discriminator in this context.

The most important clue that a adrenal mass is malignant is its size. A mass larger than about 6 cm carries a significantly higher risk of cancer, so this size threshold is a strong predictor and often prompts surgical removal.

Imaging features that suggest benign disease, like a lipid-rich appearance on CT or MRI, point toward an adrenal adenoma because benign adenomas typically contain intracellular lipid that lowers radiodensity. Normal hormonal function indicates the mass isn’t secreting excess adrenal hormones, but many malignant lesions can be nonfunctional, so normal function doesn’t reliably rule out cancer. Border characteristics can help, but they’re less definitive than size—malignant tumors often have irregular or infiltrative borders, yet a large size remains the strongest discriminator in this context.