"Incidentaloma" in a Middle-aged Woman

June 1, 2003

A 45-year-old woman presents with multiple injuries she sustained during a skiingaccident. She has fractures of her right arm and 3 ribs, as well as numerouscontusions. An abdominal CT scan shows no hemorrhage or other traumarelatedfindings; however, a 6.7-cm left adrenal mass is detected.

A 45-year-old woman presents with multiple injuries she sustained during a skiingaccident. She has fractures of her right arm and 3 ribs, as well as numerouscontusions. An abdominal CT scan shows no hemorrhage or other traumarelatedfindings; however, a 6.7-cm left adrenal mass is detected.HISTORY
Before the accident, the patient was healthy. She has no significant medicalconditions; her only medications are vitamin supplements and an oral contraceptive.She has no history of back pain or hematuria.PHYSICAL EXAMINATION
Body habitus is normal; no skin lesions or striae; no hirsutism. Heart rateis 92 beats per minute; respiration rate, 16 breaths per minute; and blood pressure,118/78 mm Hg. Heart and lungs are normal. Abdomen and flanks aresoft and nontender, without palpable masses.LABORATORY RESULTS
Results of a hemogram, serum chemistry panel, and urinalysis are normal.Which of the following is the optimal strategy for evaluation of theadrenal mass?A. Order a chest CT scan, measure serum cortisol level at 4 PM, and repeatthe abdominal imaging in 3 months.B. Order a 1-mg dexamethasone suppression test, measurement of plasmafree metanephrines, and a surgical consultation.C. Measure plasma renin and aldosterone levels, measure serum cortisollevel at 8 AM, and repeat abdominal imaging in 6 months.D. Measure serum testosterone level, measure fasting plasma epinephrineand norepinephrine levels, and order a surgical consultation.CORRECT ANSWER: B
This patient has what is commonly referred to as an "incidentaloma"--a clinically inapparent adrenal mass thatis discovered inadvertently during diagnostic testing ortreatment of a condition unrelated to adrenal disease.1Although precise incidence figures are not available, technologicimprovements in and more frequent use of imagingtechniques such as CT and MRI have clearly resultedin an increase in incidentalomas. The incidence at autopsyis 2.1%.2Incidentalomas may represent potentially fatal lesions(adrenal cortical carcinomas) or lesions associated withsignificant morbidity (hormonally active adrenal tumors,such as pheochromocytomas, aldosteromas, or those thatresult in subclinical hypercortisolism); thus, the clinicalevaluation focuses on the exclusion of these entities. Whenan adrenal mass is detected as an incidental finding, thekey concerns are:

  • Is the lesion a malignant adrenocortical carcinoma or ametastasis from another source?
  • Is there evidence of adrenal hyperfunction?

Exclusion of malignancy.

Benign nonfunctioningadrenal adenomas are rarely larger than 4 to 6 cm in diameter.Among patients with lesions larger than 6 cm, the incidenceof cancer is 25%.

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Thus, because this patient's adrenalmass is 6.7 cm, surgical removal is indicated (choices Band D). Waiting 3 months (choice A) or 6 months (choiceC) is too conservative an approach for a lesion of this size.However, before the patient undergoes surgery, biochemicalevaluation for Cushing syndrome and pheochromocytomais necessary because both disorders requirespecific perioperative management. If the urinary freecortisol level is elevated, the patient will be at risk for hypoadrenalismafter the mass is removed and she will requirestress glucocorticoids until her postoperative statuscan be established. Elevated urinary catecholamine or catecholaminemetabolite levels--which indicate pheochromocytoma--signal the need for volume repletion and administrationof α-adrenergic blockers before surgery andexpert perioperative anesthesia care.

Exclusion of hormonally active tumors.

Dependingon the clinical presentation, the biochemical screeningevaluation may include:

  • Measurement of urinary free cortisol level.
  • A 1-mg overnight dexamethasone suppression test.
  • Measurement of plasma renin and aldosterone levels.
  • Measurement of plasma free metanephrine levels.
  • Measurement of urinary catecholamine and catecholaminemetabolite levels.
  • Measurement of serum potassium level.
  • Measurement of plasma testosterone and 17-ketosteroidlevels (in women).

Blood pressure and results of a chemistry panel arenormal in this patient, which makes an aldosteroma unlikely.Adrenal hypersecretion of androgens is not common inadults; moreover, this patient has no clinical stigmata of thecondition. Thus, measurement of serum testosterone levels(choice D) is not appropriate.In this patient, the most appropriate screening studiesare those for pheochromocytoma and subclinical hypercortisolism.A recent review suggests that a 1-mg dexamethasonesuppression test and measurement of plasma freemetanephrines (choice B) are the optimal screening testsfor subclinical hypercortisolism and pheochromocytoma,respectively.1 The 1-mg dexamethasone test is superior torandom measurement of serum cortisol levels (choices Aand C) because cortisol levels fluctuate throughout theday and may be normal in patients with subclinical hypercortisolism.Measurement of plasma free metanephrinelevels adds sensitivity and specificity to an evaluation forpheochromocytoma and is superior to catecholamine measurementalone (choice D).

Outcome of this case.

The resected mass was alipoma.