Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. GENITOURINARY IMAGING GENITOURINARY 805 From the Radiologic Pathology Archives1 Adrenal Tumors and Tumor-like Conditions in the Adult: Radiologic-Pathologic Correlation2 Grant E. Lattin, Jr, MD Eric D. Sturgill, MD Advanced imaging often reveals adrenal tumors and tumor-like Charles A. Tujo, MD conditions in both symptomatic and asymptomatic patients. When Jamie Marko, MD adrenal disease is clinically suspected, cross-sectional imaging can Katherine W. Sanchez-Maldonado, MS be helpful in evaluating the etiology of the patient’s symptoms. William D. Craig, MD When adrenal disease is incidentally identified, what the clinician Ernest E. Lack, MD and patient really want to know is whether the findings are benign or malignant, as this ultimately will affect their next step in manage- Abbreviations: ACA = adrenal cortical adenoma, ACC = adrenal cortical carcinoma, ACH = adrenal ment. Using radiologic-pathologic correlation, we broadly classify cortical hyperplasia, ACTH = adrenocorticotropic common, uncommon, and rare tumors and tumor-like conditions hormone, EAP = extra-adrenal paraganglioma, FDG = fluoro-2-deoxy-D-glucose, H-E = hema- that can occur in the adrenal as benign or malignant. This classi- toxylin-eosin, IVC = inferior vena cava, MIBG = fication follows predominant trends in observed biologic behavior metaiodobenzylguanidine while acknowledging those tumors that may behave in the minority RadioGraphics 2014; 34:805–829 in an unpredictable manner. We review the clinical background and Published online 10.1148/rg.343130127 presentation of functional adrenal tumors including Conn syn- Content Codes: drome, Cushing syndrome, and catecholamine-secreting tumors, as 1Supported by the American Institute for Radiologic Pathology (AIRP), the Joint Pathology Center (JPC), well as their relationship with adrenal anatomy. We discuss a variety and Uniformed Services University of the Health of benign tumors, including adrenal cortical adenoma (including Sciences (USU). oncocytoma) and pheochromocytoma, as well as uncommonly and 2From the Department of Radiology and Radio- logical Sciences, F. Edward Hébert School of Medi- rarely encountered tumors such as myelolipoma, hemangioma, cine, Uniformed Services University of the Health lymphangioma, schwannoma, ganglioneuroma, and adenomatoid Sciences, 4301 Jones Bridge Rd, Bethesda, MD 20814 (G.E.L., C.A.T., J.M., W.D.C.); American tumor. A variety of tumefactive but nonneoplastic lesions are ad- Institute for Radiologic Pathology, Silver Spring, dressed, including adrenal cortical hyperplasia, adrenal hemor- Md (G.E.L., E.D.S., W.D.C.); Department of Ra- diology, Naval Medical Center Portsmouth, Ports- rhage, adrenal cysts, and infections. Malignant tumors discussed mouth, Va (E.D.S.); Department of Radiology, Da- include adrenal cortical carcinoma, the rare malignant pheochro- vid Grant USAF Medical Center, Travis AFB, Calif (C.A.T.); Department of Radiology, Walter Reed mocytoma, lymphoma, metastases, and sarcomas. For each tumor National Military Medical Center, Bethesda, Md and tumor-like lesion, the clinical presentation, epidemiology, key (J.M.); School of Medicine, Georgetown University, Washington, DC (K.W.S.); Department of Radiol- imaging findings, diagnostic differential considerations, and man- ogy, Suburban Hospital, Bethesda, Md (W.D.C.); agement options are briefly addressed. Finally, an approach to the and Department of Endocrine Pathology, The Joint Pathology Center, Silver Spring, Md (E.E.L.). Re- workup of suspected or incidentally discovered tumors is presented ceived November 12, 2013; revision requested Feb- based on a selected literature survey and our clinical experience. ruary 18, 2014, and received February 28; accepted March 3. For this journal-based SA-CME activity, Radiologists play an important role in identification and diagnosis the authors, editor, and reviewers have no financial of adrenal tumors and tumor-like conditions in both symptomatic relationships to disclose. Address correspondence to G.E.L. (e-mail: [email protected]). and asymptomatic patients. The opinions and assertions contained herein are the ©RSNA, 2014 • radiographics.rsna.org private views of the authors and are not to be con- strued as official or as representing the views of the De- partments of the Army, Navy, Air Force, or Defense. SA-CME LEARNING OBJECTIVES Introduction After completing this journal-based SA- Conditions affecting the adrenals are commonly identified at cross- CME activity, participants will be able to: sectional imaging in the adult patient population. Sometimes these ■■Discuss the clinical presentation and lesions are clinically suspected, but more often they are incidentalo- imaging spectrum of both benign and malignant adrenal tumors and tumor-like mas (ie, adrenal masses discovered during diagnostic testing for an- conditions in the adult. other condition), which represent tumors or tumor-like conditions ■■Describe key clinical and imaging find- that a radiologist will initially assess, categorize, and potentially ings in multiple benign and malignant tumors of the adult adrenal with patho- logic correlation. ■■Summarize diagnosis, treatment op- tions, and prognosis for these tumors. See www.rsna.org/education/search/RG. 806 May-June 2014 radiographics.rsna.org diagnose, thus influencing the trajectory of clini- (6). Plasma aldosterone-to-renin ratio is the di- cal management. These tumors, in symptomatic agnostic test of choice. as well as in asymptomatic individuals, may be classified in many ways, according to size, ana- Cushing Syndrome tomic site of origin, endocrinologic signature, Between 2% and 15% of ACAs produce corti- morphologic features, or biologic behavior. We sol (2). Hypercortisolism can result in Cushing have opted to classify the tumors and tumor- syndrome, which is characterized by symptoms like lesions in this article according to the latter such as weight gain and deposition of adipose schema, as do our pathology colleagues, placing tissue (especially in the face, neck, or back), lesions into benign or malignant categories ac- hypertension, easy bruisability, amenorrhea, cording to their predominant behaviors, as we hirsutism, acne, muscle weakness, diabetes, and believe that this ultimately answers the question mood changes. Noniatrogenic hypercortisolism that referring clinicians and patients seek. resulting in Cushing syndrome may be pituitary dependent (Cushing disease) (~60%–70% of Clinical Background cases in adults) with the remaining cases being and Endocrine Syndromes pituitary independent (7). Pituitary-indepen- Findings from abdominal computed tomographic dent causes include ectopic adrenocorticotropic (CT) studies suggest that the prevalence of adre- hormone (ACTH) production, rarely ectopic nal incidentalomas is approximately 5% (1). Only corticotropic-releasing factor (CRF) secretion, a small number of adrenal tumors are functional primary pigmented nodular adrenocortical dis- and an even smaller number are malignant (2). ease (PPNAD), and macronodular hyperplasia It is important to consider that the majority of with marked adrenal enlargement (MHMAE). adrenal lesions are clinically silent when recom- Cushing syndrome caused by an adrenal ad- mending follow-up imaging of asymptomatic enoma is classified as an ACTH-independent patients. How to best perform follow-up for these form of hypercortisolism. ACAs causing Cush- masses is controversial and varies by medical ing syndrome are often >2 cm in size and read- specialty (3). Recent imaging guidelines suggest ily visualized with CT or MR imaging (8). Pre- that incidentalomas with imaging features diag- clinical or subclinical Cushing syndrome occurs nostic of a benign mass (eg, myelolipoma, small when a patient has a cortisol-secreting tumor, cyst, adenoma) require no additional workup or but steroid secretion is insufficient to elicit clas- follow-up imaging, and that stability at imaging sic signs or symptoms of the syndrome. of an adrenal mass for 12 months makes a benign diagnosis most likely (3,4). Increased Catecholamines Most incidentally discovered adrenal tumors The reported frequency of pheochromocytoma are nonfunctional and benign, with fewer than among adrenal masses is variable, ranging from 10% having detectable endocrine functionality 1.5% to 23%, with the actual prevalence likely and fewer than 5% being malignant (5). Some being near 3%–6% (3). The widespread use of diseases of adrenal origin may not require imag- CT and magnetic resonance (MR) imaging is ing for initial clinical recognition, but imaging allowing more pheochromocytomas to be de- almost always plays an important role during tected before the patient presumably becomes disease workup in confirming the etiology. symptomatic, although not all patients become symptomatic, with increasing numbers of unan- Conn Syndrome ticipated pheochromocytomas being discovered Aldosterone-secreting adrenal cortical adenoma at imaging performed for unrelated symptoms (aldosteronoma) accounts for up to 2% of all (9). In symptomatic patients, pheochromocyto- unanticipated adrenal masses (2). Conn syn- mas release catecholamines, which may lead to a drome, or primary aldosteronism due to an classic triad of symptoms consisting of episodic adrenal cortical adenoma (ACA), has classically headache, sweating, and tachycardia,