Genitourinary Imaging Pictorial Essay Johnson et al. MDCT of drenal Disease Genitourinary Imaging Pictorial Essay Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved Pamela T. Johnson 1 Karen M. Horton Elliot K. Fishman Johnson PT, Horton KM, Fishman EK Keywords: adrenal gland, adrenal hyperplasia, hemorrhage, infection, MDCT, pseudocyst DOI:10.2214/JR.09.2551 Received February 9, 2009; accepted after revision March 19, 2009. 1 ll authors: The Russell H. Morgan Department of Radiology and Radiologic Science, Johns Hopkins School of Medicine, 601 N Caroline St., Rm. 3140D, altimore, MD 21287. ddress correspondence to P. T. Johnson (pjohnso5@jhmi.edu). CME This article is available for CME credit. See www.arrs.org for more information. JR 2009; 193:1128 1135 0361 803X/09/1934 1128 merican Roentgen Ray Society drenal Imaging with MDCT: Nonneoplastic Disease OJECTIVE. The adrenal gland can enlarge or alter morphology in the presence of a range of nonneoplastic entities, including hyperplasia, hemorrhage, infection, or cystic mass. This article presents a description and representative CT images for each of these disorders. CONCLUSION. Proper characterization is essential to ensure that life-threatening sequelae from ddisonian crisis are averted in infection and hemorrhage, or to identify leavealone lesions such as pseudocyst and chronic calcification. I n addition to neoplastic disease, a range of disorders can alter the size or morphology of the adrenal gland. These include hyperplasia, hemorrhage, infection, and cystic lesions. lthough these abnormalities may not represent potential malignancy, identification is important nonetheless. ssociated clinical manifestations that can be corrected are not insignificant (i.e., Cushing s syndrome, Conn s syndrome, refractory hypertension), secondary adrenal insufficiency can be life-threatening (i.e., hemorrhage), and findings may represent systemic infection (i.e., granulomatous disease). In this article, the CT appearance of adrenal hyperplasia, hemorrhage, granulomatous infection, calcification, and pseudocyst are shown in conjunction with discussion of important correlative clinical findings. Hyperplasia Vincent et al. [1] reported, in a study performed with 10-mm sections, that normal adrenal limbs should be 5 mm. Performing CT with both 10- and 3- to 5-mm sections, Sohaib et al. [2] showed that slightly, but significantly larger measurements were obtained using the thinner sections (mean limb width, ~ 15% greater). Normal adrenal shape varies, even in the same patient at different levels, according to Wilms et al. [3]. The right side can be linear, an inverted V (with or without asymmetric limbs), horizontally linear, or K-shaped. The left adrenal gland has been described as an inverted V, an inverted Y, triangular, or linear [2, 3]. Hormonal abnormalities related to the adrenal gland include hypercortisolism (Cushing s syndrome) and hyperaldosteronism (Conn s syndrome). Hypercortisolism is adrenocorticotropic hormone (CTH) dependent in 80 85% of cases: of pituitary origin or in Cushing s disease in 80 85%, due to an ectopic CTH-secreting tumor in 10 15% [2, 4]; CTH-independent Cushing s syndrome is due to either adrenal adenoma or carcinoma in most cases [4]. The adrenal enlargement is most commonly diffuse (Figs. 1 and 2) but can be nodular or mixed. In patients with CTH-dependent hyperplasia, Sohaib et al. [2] showed that ectopic tumor CTH produced adrenal hyperplasia in a higher percentage of cases (90%) than pituitary CTH hypersecretion. In those patients with hyperplasia due to ectopic CTH production, the adrenal gland morphology was lobular in 40% and either smooth or nodular in 30% each. In the setting of pituitary-induced hyperplasia, 62% of adrenals were enlarged, most commonly smooth (55%), followed by lobular (28%) or nodular (17%) [2]. In the setting of hyperaldosteronism (Conn s syndrome), the absence of an adenoma traditionally suggested adrenal hyperplasia as the cause. With improved CT resolution, gland measurements have proven useful. Lingam et al. [5] revealed that the medial and lateral limbs were significantly larger in hyperplasia. cutoff of 5 mm was 47% sensitive and 100% specific; using a 3-mm cutoff, sensitivity was 100% and specificity, 54%. In comparison, the absence of 1128 JR:193, October 2009
Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved an adenoma at imaging was 93.3% sensitive and 84.6% specific. Hemorrhage Potential causes of unilateral or bilateral hemorrhage [6 9] are listed in Table 1. Tumors that are known to hemorrhage include myelolipoma, hemangioma, pheochromocytoma, adenoma, adrenal cortical carcinoma, and metastases. Patients with antiphospholipid antibody syndrome (PLS) who develop adrenal hemorrhage (Fig. 3) usually have concomitant predisposing factors such as infection, anticoagulation, or a postoperative state. Provenzale et al. [10] reported on a series of four primary antiphospholipid antibody syndrome patients who had adrenal hemorrhage diagnosed with CT. In three of the four, the hemorrhage was bilateral, and two presented with abrupt onset of adrenal insufficiency. Trauma typically produces unilateral hemorrhage. In a study by Rana et al. [8] that included 54 adrenal hematomas, most were right-sided (Fig. 4), and adrenal hemorrhage was associated with injuries of higher severity. Right-sided hemorrhage was associated with liver, spleen, bilateral renal injuries, and pneumothorax; when hemorrhage involved the left adrenal, splenic, left kidney, and pneumothoracic injuries were the most common accompanying injuries. In this series of 51 patients, the hematomas appeared as a mass (2/3 ovoid, 1/3 round) with mean maximum diameter of 2.8 cm and mean attenuation of 52 ± 12 (SD) HU. Periadrenal stranding was identified in most cases (89%) [8]. Sinelnikov et al. [9] reported their findings in 73 traumatic adrenal injuries, 77% of which were right-sided. CT often revealed a focal hematoma (30%) or mass (11%), but injury was also reflected by an indistinct (27%) or enlarged (18%) gland. Most patients in this series also had periadrenal stranding. oth investigations noted that active contrast extravasation was an infrequent finding (1 6%) [8, 9]. Infection mong infectious disorders, both tuberculosis (T) and histoplasmosis can involve the adrenal gland [11 15]. In addition to the morbidity associated with these systemic infections, if most (> 90%) of the gland is destroyed, patients develop ddison s disease [11, 14]. The appearance of the gland at CT depends on the chronicity of the infection and whether it has been treated. Most patients have bilateral gland enlargement, masslike in 50 65% MDCT of drenal Disease TLE 1: Causes of drenal Hemorrhage Unilateral Spontaneous (rule out tumor) Trauma iopsy Incidental Tumor and adreniform in 35 50% [11, 12, 14]. Unenhanced CT shows attenuation to be more commonly homogeneous, but one third are heterogeneous [14]. fter contrast infusion, the classic appearance of peripheral enhancement with central necrosis is seen in 40 50% of cases; alternatively, the glands may enhance heterogeneously [11, 14]. Yang et al. [11] showed that peripheral enhancement with central necrosis is significantly more common in tuberculosis than tumor. Untreated, T causes adrenal calcification in 40 60% of patients [11, 14]. trophy and calcification both develop after treatment [12, 13]. Calcification drenal calcification may reflect granulomatous infection (Fig. 5), may evolve after previous hemorrhage (Fig. 6), or can be present in an adrenal mass (myelolipoma, adrenocortical carcinoma [CC], pheochromocytoma, cyst) [11 14]. Cyst The most common adrenal cyst is reportedly a pseudocyst (Figs. 7 and 8), believed to be the sequela of previous hemorrhage (or possibly infection). These can also arise secondary to bleeding within a tumor, for example as occurs with melanoma [7]. Wang et al. [16] correlated CT appearance with pathology in seven pseudocysts. Only 43% (3/7) were predominantly cystic, with mixed or solid lesions reflecting organized hematoma; the predominantly cystic lesions contained liquefied hemorrhage (86%). Pseudocysts may be unilocular (Figs. 6 8) or multilocular (Fig. 9); calcification mural, septal, or central was identified in 43%. In six of the 32 pseudocysts analyzed by Erickson et al. [17], associated tumors were identified, including pheochromocytoma, adenoma, and CC. ilateral Heparin-associated thrombocytopenia ntiphospholipid antibody syndrome Use of steroids nticoagulation Stress: surgery, burn, sepsis, hypotension (Sepsis or stress) Waterhouse-Friderichsen syndrome: meningococcal sepsis Spontaneous in setting of bilateral metastases (Trauma) (Incidental) Note Causes that are less frequent are indicated by parentheses. Other adrenal cysts include endothelial cysts, and less commonly, epithelial and parasitic cysts (i.e., echinococcus) [18]. In a case series and literature review, Rozenblit et al. [19] reported that pseudocysts were more likely to be unilocular (81%) with calcification (74%); multilocularity and calcification were identified in 44% of endothelial cysts. Those authors also noted that the wall was generally imperceptible in benign cystic masses but measured 4 mm in a cystic pheochromocytoma and > 6 mm in a cystic CC. ccordingly, although it may not be possible to definitively determine whether the underlying mass is benign or malignant, the presence of nodular wall thickening (Fig. 10) should prompt consideration of tumor. In addition, the cyst fluid density was higher in tumors (22 25 HU) than in benign nonhemorrhagic cysts (5 17 HU); two hemorrhagic cysts measured 67 and 75 HU [19]. Conclusion With respect to adrenal imaging, the key role of CT is to distinguish leave-alone lesions from those requiring further evaluation or representing specific disease processes. Correct characterization of benign entities that do not require intervention (i.e., longstanding calcification or pseudocyst) is important to properly guide patient management. Identification of hyperplasia warrants additional clinical evaluation. In addition to these, nonneoplastic pathologic processes that can involve the adrenal glands range from harbingers of serious systemic disease, as in tuberculosis, to complications of underlying medical conditions, such as hemorrhage in the setting of coagulopathy. ecause adrenal insufficiency is a potentially life-threatening sequela of bilateral infection or hemorrhage, findings must be recognized as such and promptly communicated. JR:193, October 2009 1129
Johnson et al. Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved References 1. Vincent JM, Morrison ID, rmstrong P, Reznek RH. The size of normal adrenal glands on computed tomography. Clin Radiol 1994; 49:453 455 2. Sohaib S, Hanson J, Newell-Price JD, et al. CT appearance of the adrenal glands in adrenocorticotrophic hormone-dependent Cushing s syndrome. JR 1999; 172:997 1002 3. Wilms G, aert, Marchal G, Goddeeris P. Computed tomography of the normal adrenal glands: correlative study with autopsy specimens. J Comput ssist Tomogr 1979; 3:467 469 4. Doppman JL, Chrousos GP, Papanicolaou D, Stratakis C, lexander HR, Nieman LK. drenocorticotropin-independent macronodular adrenal hyperplasia: an uncommon cause of primary adrenal hypercortisolism. Radiology 2000; 216: 797 802 5. Lingam RK, Sohaib S, Vlahos I, et al. CT of primary hyperaldosteronism (Conn s syndrome): the value of measuring the adrenal gland. JR 2003; 181:843 849 6. Vella, Nippoldt T, Morris JC. drenal hemorrhage: a 25-year experience at the Mayo Clinic. Mayo Clin Proc 2001; 76:161 168 7. Kawashima, Sandler CM, Ernst RD, et al. Imaging of nontraumatic hemorrhage of the adrenal gland. RadioGraphics 1999; 19:949 963 8. Rana I, Kenney PJ, Lockhart ME, et al. drenal gland hematomas in trauma patients. Radiology 2004; 230:669 675 9. Sinelnikov O, bujudeh HH, Chan D, Novelline R. CT manifestations of adrenal trauma: experience with 73 cases. Emerg Radiol 2007; 13:313 318 10. Provenzale JM, Ortel TL, Nelson RC. drenal hemorrhage in patients with primary antiphospholipid syndrome: imaging findings. JR 1995; 165:361 364 11. Yang ZG, Guo YK, Li Y, Min PQ, Yu JQ, Ma ES. Differentiation between tuberculosis and primary tumors in the adrenal gland: evaluation with contrast enhanced CT. Eur Radiol 2006; 16:2031 2036 12. Liatsikos EN, Kalogeropoulou CP, Papathanassiou Z, et al. Primary adrenal tuberculosis: role of computed tomography and CT-guided biopsy in diagnosis. Urol Int 2006; 76:285 287 13. Guo YK, Yang ZG, Li Y, et al. ddison s disease due to adrenal tuberculosis: contrast-enhanced CT features and clinical duration correlation. Eur J Radiol 2007; 62:126 131 14. Ma ES, Yang ZG, Li Y, Guo YK, Deng YP, Zhang XC. Tuberculous ddison s disease: morphological and quantitative evaluation with multidetectorrow CT. Eur J Radiol 2007; 62:352 358 15. Kumar N, Singh S, Govil S. drenal histoplasmosis: clinical presentation and imaging features in nine cases. bdom Imaging 2003; 28:703 708 16. Wang LJ, Wong YC, Chen CJ, Chu SH. Imaging spectrum of adrenal pseudocysts on CT. Eur Radiol 2003; 13:531 535 17. Erickson L, Lloyd RV, Hartman R, Thompson G. Cystic adrenal neoplasms. Cancer 2004; 101: 1537 1544 18. Pradeep PV, Mishra K, ggarwal V, hargave PRK, Gupta SK, garwal. drenal cysts: an institutional experience. World J Surg 2006; 30: 1817 1820 19. Rozenblit, Morehouse HT, mis ES. Cystic adrenal lesions: CT features. Radiology 1996; 201: 541 548 Fig. 1 79-year-old woman with adrenocorticotropic hormone (CTH) dependent Cushing s disease. and, xial arterial () and venous phase () images show that limbs of adrenal glands (arrows) are enlarged bilaterally, but shape is adreniform, compatible with hyperplasia. Precise source of Cushing s disease could not be localized and symptoms were not controlled by medication, necessitating adrenalectomy. Pathology revealed nodular expansion of adrenal cortices bilaterally. 1130 JR:193, October 2009
MDCT of drenal Disease Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved Fig. 2 27-year-old woman with history of Cushing s disease. and, xial unenhanced CT image () and coronal contrast-enhanced multiplanar reformation () show bilateral adrenal enlargement (arrows) and mild asymmetry of lateral limbs (arrowheads, ). Fig. 3 51-year-old man with antiphospholipid antibody syndrome and clinical concern for pulmonary embolism underwent contrast-enhanced CT (not shown), which revealed high-density right adrenal mass with mild periadrenal stranding. and, Repeated MDCT scan 12 hours later () for delayed phase characterization confirmed persistent high density (arrow, ). In conjunction with previous study from 7 days prior () showing no adrenal mass, findings are compatible with adrenal hemorrhage. Subsequent studies over 4 months confirmed progressive decrease in size. JR:193, October 2009 1131
Johnson et al. Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved Fig. 4 69-year-old man with history of lymphoma and motor vehicle accident 2 months earlier, who presented with right-sided flank pain., xial unenhanced CT scan shows 6.4-cm mildly heterogeneous mass (arrows) in right adrenal gland with some regions of high attenuation (47 HU), compatible with resolving hematoma. MRI confirmed presence of hemorrhage, and PET/CT from several weeks earlier (not shown) revealed no hypermetabolic activity below diaphragm., Follow-up CT image 10 months later shows decrease in size and liquefaction (18 HU) of mass (arrows), consistent with interval resolution of hemorrhage. Fig. 5 54-year-old man with pancreatic mass (not shown). and, xial () and coronal () volume-rendered images from contrast-enhanced CT show dense calcification of both adrenal glands (arrows), compatible with prior granulomatous disease. 1132 JR:193, October 2009
MDCT of drenal Disease Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved C Fig. 6 58-year-old woman with incidentally discovered adrenal mass. D, Unenhanced axial image (), unenhanced coronal multiplanar reformation (), delayed contrast-enhanced coronal volume-rendered image (C), and coronal volume-rendered image with parameters modified to show calcification (D) show nonenhancing, low-density right adrenal mass (arrows, C) with dense peripheral calcification, compatible with pseudocyst or old hematoma. ttenuation in center of lesion ranged from 23 HU on unenhanced, to 21 HU at 1 minute and 18 HU on delayed acquisition, reflecting lack of enhancement. D JR:193, October 2009 1133
Johnson et al. Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved Fig. 7 55-year-old woman with abdominal pain. and, Coronal arterial () and delayed phase () volume-rendered images from IV contrast-enhanced MDCT show 4 3 cm cystic mass (arrows) with dense calcifications superiorly and inferiorly (arrowheads), most compatible with pseudocyst caused by old adrenal hematoma. Fig. 8 55-year-old man with stable cystic mass in right adrenal gland. D, xial unenhanced (), axial contrast-enhanced (), and contrast-enhanced coronal volume-rendered (C and D) images show cyst (arrows) with peripheral calcification. Fluid measured 13 HU. Findings are most compatible with pseudocyst caused by old hematoma. C D 1134 JR:193, October 2009
MDCT of drenal Disease Downloaded from www.ajronline.org by 172.68.189.103 on 08/23/18 from IP address 172.68.189.103. Copyright RRS. For personal use only; all rights reserved C Fig. 9 48-year-old woman with history of pancreatitis secondary to pancreas divisum and hypertriglyceridemia. and, Coronal () and sagittal () multiplanar reformations from contrastenhanced CT show bilobed cyst (arrows) and mural calcification in region of adrenal gland. C, Varices in the gastric fundus (arrowheads) reflect splenic vein occlusion. iopsy of suprarenal mass confirmed pseudocyst. Fig. 10 47-year-old woman with abdominal pain and history of neurofibromas. and, ilateral pheochromocytomas are present in adrenal glands, depicted on contrast-enhanced axial section () and coronal multiplanar reformation (). Leftsided mass is predominantly cystic and right is solid with cystic components. Note thickened, irregular wall (arrowheads), a finding associated with neoplasms as opposed to pseudocyst. FOR YOUR INFORMTION This article is available for CME credit. See www.arrs.org for more information. JR:193, October 2009 1135