Curriculum · Metabolic and Endocrine and Diabetes Mellitus
Adrenal incidentaloma
What it is
An adrenal incidentaloma is a lesion of the adrenal gland that is found while the patient is being looked at for another reason. Its weight in a hypertensive patient is that it marks the hypertension as endocrine: in the tables of secondary causes of hypertension, hypertension with an adrenal incidentaloma is written as a clinical clue under primary aldosteronism, under pheochromocytoma and under Cushing syndrome.
Causes and risk
The endocrine causes of hypertension listed together are primary hyperaldosteronism (Conn syndrome), pheochromocytoma, hypercortisolism (Cushing syndrome), hyperthyroidism, primary hyperparathyroidism, congenital adrenal hyperplasia and acromegaly. Primary hyperaldosteronism is an excess of aldosterone caused by autonomous overproduction, and it is typically due to adrenal hyperplasia, most commonly bilateral, or to an adrenal adenoma, typically unilateral. Besides an adrenal incidentaloma, the findings that indicate further workup for primary hyperaldosteronism are resistant hypertension, stroke at under 40 years of age, a family history of early-onset hypertension or of primary hyperaldosteronism, and possible hypokalemia with consequent metabolic alkalosis. For pheochromocytoma the same list gives resistant hypertension, paroxysmal hypertension, episodes of headaches, palpitations and diaphoresis, a family history of endocrine tumors, and cutaneous features suggestive of NF type 1.