Adrenal incidentaloma

An adrenal mass found incidentally on abdominal imaging; most are non-functioning adrenal cortical adenomas. Evaluation answers two questions: is it functional? and is it malignant?

Is it functional? (clinical clues)

• Hypercortisolism — central obesity, easy bruising, striae, severe hypertension, virilisation
• Aldosteronism — muscle cramps, weakness, hypertension
• Phaeochromocytoma — headaches, weight loss, sweating, palpitations
• Metastatic cancer — weight loss, prior cancer/smoking, lymphadenopathy

Work-up

• History and examination for the functional syndromes above.
• Hypercortisolism — 1 mg overnight dexamethasone suppression test.
• Phaeochromocytoma — plasma metanephrines and/or 24-hour urinary fractionated metanephrines.
• Aldosteronism (if hypertensive) — aldosterone-to-renin ratio.
• Malignancy risk — assessed on imaging (irregular shape, size >4 cm, high unenhanced attenuation); characterise with a contrast-enhanced CT and refer for specialist evaluation.