A 65-year-old woman comes to the emergency department due to abdominal pain. The pain subsequently subsides, but a 3.5-cm left adrenal mass is seen on abdominal CT scan. No other abnormalities are noted. The mass appears rounded and vascular, and has a high attenuation (25 Hounsfield units) . The patient has experienced no headaches, palpitations, mood swings, or recent weight gain. Medical history is notable for hypertension that is well controlled with amlodipine. She has a current 40-pack-year smoking history. Family history is unremarkable.
Blood pressure is 138/90 mm Hg and pulse is 76/min. BMI is 26 kg/m².
Fasting laboratory results are as follows:
Which of the following is the most appropriate next step in evaluating this patient?

Question

A 65-year-old woman comes to the emergency department due to abdominal pain. The pain subsequently subsides, but a 3.5-cm left adrenal mass is seen on abdominal CT scan. No other abnormalities are noted. The mass appears rounded and vascular, and has a high attenuation (25 Hounsfield units) . The patient has experienced no headaches, palpitations, mood swings, or recent weight gain. Medical history is notable for hypertension that is well controlled with amlodipine. She has a current 40-pack-year smoking history. Family history is unremarkable.
Blood pressure is 138/90 mm Hg and pulse is 76/min. BMI is 26 kg/m².
Fasting laboratory results are as follows:

Which of the following is the most appropriate next step in evaluating this patient?

Quizplus · Accepted Answer

11ec193a_95ef_efd4_853d_3b2329e6a3c8_MD0002_00 This patient has an adrenal incidentaloma, defined as a mass >1 cm in diameter discovered incidentally on radiology studies. The objective in evaluating an adrenal incidentaloma is to determine the risk of malignancy and assess for subclinical endocrine activity. CT findings that suggest malignancy include bilateral or large (>4 cm) lesions, irregular or inhomogeneous morphology, contrast enhancement with delayed contrast washout, and high radiographic attenuation. Attenuation is expressed in Hounsfield units (HU), which are an estimate of the radiodensity of a lesion. Low-attenuation lesions (<10 HU) typically have a high lipid content and are usually benign adenomas; high-attenuation lesions (>20 HU) are more likely to represent adrenal metastasis, adrenocortical carcinoma, or pheochromocytoma. This patient's lesion has high attenuation but otherwise benign features (eg, unilateral, round, <4 cm). Metabolic evaluation of an adrenal incidentaloma should include studies to screen for pheochromocytoma (plasma [high-likelihood lesions] or urinary [low-likelihood lesions] metanephrines), Cushing syndrome (overnight dexamethasone suppression test), and hyperaldosteronism (plasma aldosterone and plasma renin activity). Although this patient does not have the classic triad of symptoms (paroxysmal headache, sweating, tachycardia), the attenuation and vascularity of the lesion suggest pheochromocytoma. Patients with functional adrenal masses should be evaluated for surgical resection, but those with nonfunctioning masses that appear benign can be followed with serial CT scan and biochemical testing (Choice D). (Choice A) This patient has well-controlled blood pressure and no symptoms of catecholamine hypersecretion. 24-hour blood pressure monitoring is not necessary, but alpha blockade should be given prior to resection if pheochromocytoma is confirmed. (Choice B) Needle biopsy of a vascular mass (which could be a pheochromocytoma) can lead to hemorrhage and hypertensive crisis. This patient should have functional testing before attempting biopsy. Biopsy can differentiate benign adrenal masses from metastatic lesions but cannot differentiate adrenal adenomas from adrenocortical carcinoma. (Choice C) Other than high attenuation, this patient's lesion appears benign and metabolic studies should be performed before searching for a primary tumor. Educational objective: An adrenal incidentaloma is a mass >1 cm in diameter discovered incidentally on radiology studies. Risk for malignancy can be assessed based on morphological characteristics. Patients should be tested for biochemical evidence of Cushing syndrome (dexamethasone suppression test), pheochromocytoma (plasma or urinary metanephrines), and hyperaldosteronism (plasma aldosterone and plasma renin activity). __________ References: Medical and surgical evaluation and treatment of adrenal incidentalomas. (http://www.ncbi.nlm.nih.gov/pubmed/21632813)

A 65-Year-Old Woman Comes to the Emergency Department Due to Abdominal