Images In Clinical Urology
Adrenocortical Carcinoma Masquerading as a Benign Adenoma on Computed Tomography Washout Study
Jay Simhan, Daniel Canter, Ervin Teper, Marc C. Smaldone, Ninad Patil, Arthur Patchefsky, Marlane C. Guttmann, Barton Milestone, Yu-Ning Wong, Lisa A. Hicks, Robert G. Uzzo, and Alexander Kutikov
An incidental adrenal mass is a common finding on cross-sectional imaging, with most of these lesions being benign adenomas. Indications for adrenalectomy turn on the likelihood that a mass is malignant or whether it exhibits metabolic activity. Modern imaging is considered highly accurate in differentiating adrenal adenomas from other adrenal pathology. We present a case of a 5-cm adrenal lesion with computed tomography washout characteristics consistent with a benign adenoma, which proved upon resection to be an adrenocortical carcinoma. UROLOGY 79: e19-e20, 2012. @ 2012 Elsevier Inc.
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A healthy 57-year-old woman was found to have an incidental, well-circumscribed, inhomoge- neous, 5-cm left adrenal mass. A magnetic res- onance imaging (MRI) study of the abdomen revealed absence of signal drop-out on opposed-phase chemical- shift sequences, findings consistent with a lipid-poor le- sion. Plasma-free metanephrines, low-dose dexametha- sone suppression test, serum renin-aldosterone ratio, estradiol, androstenedione, and 17-hydroxyprogesterone were within normal limits. A 15-minute computed to- mography (CT) washout study (Fig. 1) was performed, which revealed the lesion to have an absolute washout of 66%, indicative of an adenoma. Because no robust
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data reconcile reassuring imaging findings with worri- some tumor size, the patient underwent a left laparo- scopic adrenalectomy. Pathologic examination re-
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vealed a 6.0-cm, low-grade adrenocortical carcinoma (Figs. 2 and 3).
CT and MRI can identify benign adrenal adenomas with a high level of accuracy.1 For lipid-poor adrenal lesions, a 15-minute CT washout study is the test of choice.1,2 The ability of a CT washout to differentiate between an adenoma and an adrenocortical carcinoma has been assessed only in small cohorts (total n < 25).3,4
To our knowledge, this report represents the second adrenocortical carcinoma exhibiting CT washout consis- tent with an adenoma.3 All patients with an adrenal mass require a thoughtful approach to avoid surgical overtreat- ment.
References
1. Kutikov A, Crispen PL, Uzzo RG. Pathophysiology, evaluation, and medical management of adrenal disorders. In: Wein AJ, Kavoussi LR, Partin AW,Peters CA, eds Campbell-Walsh Urology, 10th ed. Philadelphia: Elsevier; 2012:1685-1736.
2. Boland GW, Blake MA, Hahn PF, et al. Incidental adrenal lesions: principles, techniques, and algorithms for imaging characterization. Radiology. 2008;249:756-775.
3. Szolar DH, Korobkin M, Reittner P, et al. Adrenocortical carcino- mas and adrenal pheochromocytomas: mass and enhancement loss evaluation at delayed contrast-enhanced CT. Radiology., 2005;234: 479-485.
4. Slattery JM, Blake MA, Kalra MK, et al. Adrenocortical carcinoma: contrast washout characteristics on CT. AJR Am J Roentgenol. 2006; 187:W21-W24.
5. Caoili EM, Korobkin M, Francis IR, et al. Adrenal masses: charac- terization with combined unenhanced and delayed enhanced CT. Radiology. 2002;222:629-633.
6. Kutikov A, Mallin K, Canter D, et al. Effects of increased cross- sectional imaging on the diagnosis and prognosis of adrenocortical carcinoma: analysis of the National Cancer Data Base. J Urol. In press.