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MKSAP 18 "Quiz Me!" Question: Answer and Critique
C: Subclinical Cushing disease and pheochromocytoma
Screen for adrenal hyperfunction in a patient with an incidentally noted adrenal mass.
The patient should be evaluated for primary subclinical Cushing disease and pheochromocytoma. An adrenal incidentaloma is defined as an adrenal mass greater than 1 cm in diameter that is detected on imaging performed for reasons other than suspicion of adrenal disease. The prevalence of adrenal incidentaloma increases with age and is estimated to be approximately 10% in persons aged 70 years or older. Most lesions are benign, nonfunctioning adenomas, but approximately 10% to 15% secrete excess hormones. The finding of an incidental adrenal mass prompts two main questions: (1) Is it secreting excess hormone (aldosterone, cortisol, or catecholamines)? and (2) Is it benign or malignant? Biochemical testing for pheochromocytoma, such as a 24-hour urine total metanephrine measurement, should be undertaken in all patients with adrenal incidentaloma, even in the absence of typical symptoms or hypertension. Hypertension associated with pheochromocytoma/paraganglioma can show a sustained pattern, with or without paroxysms, or occur as paroxysms only. Some patients (10% to 15%) remain normotensive. The classic triad of palpitations, headache, and diaphoresis is seen in fewer than 50% of patients with pheochromocytoma. All patients with incidental adrenal mass should also be evaluated for subclinical Cushing syndrome, a condition characterized by adrenocorticotropic hormone–independent cortisol secretion that may cause metabolic (hyperglycemia and hypertension) and bone (osteoporosis) effects of hypercortisolism, but not the more specific clinical features of Cushing syndrome, such as supraclavicular fat pads, wide violaceous striae, facial plethora, and proximal muscle weakness.
Primary adrenal insufficiency is a life-threatening disorder that often presents with insidious onset of symptoms, making diagnosis a challenge. Potential symptoms of glucocorticoid and mineralocorticoid deficiency may include fatigue, weakness, low-grade fever, weight loss, anorexia, and hypotension. This patient has no symptoms to suggest adrenal insufficiency. Furthermore, while an adrenal adenoma may be nonfunctioning, it would not be associated with findings of adrenal insufficiency.
Primary aldosteronism is a common cause of secondary hypertension. Identification of patients with primary aldosteronism is important because aldosterone has deleterious effects on the cardiovascular system, and treatment prevents progression and can sometimes reverse changes. Screening for primary aldosteronism is unnecessary in the absence of hypertension. Androgen-producing adrenal tumors are rare and lead to menstrual irregularities and virilization in women, including hirsutism, voice-deepening, increased muscle mass, increased libido, and clitoromegaly. This patient has no findings to suggest androgen excess and screening for androgen-producing tumors is therefore not indicated.
Although this patient is asymptomatic, performing no further testing may result in a missed diagnosis of subclinical Cushing disease or pheochromocytoma and is therefore inappropriate.
All patients with an adrenal adenoma should be evaluated for pheochromocytoma and subclinical Cushing disease.
Fassnacht M, Arlt W, Bancos I, et al. Management of adrenal incidentalomas: European Society of Endocrinology Clinical Practice Guideline in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol. 2016;175:G1-G34. doi:10.1530/EJE-16-0467