EDUCATION EXHIBIT 1151 Imaging of Renal Lymphoma: Patterns of Disease with Pathologic Correlation 1 LEARNING OBJECTIVES FOR TEST 5 After reading this article and taking the test, the reader will be able to:  Identify both typi- cal and atypical ra- diologic patterns seen in renal lymphoma.  List the diagnostic options in the differ- ential diagnosis of renal lymphoma.  Discuss the role of imaging-guided per- cutaneous biopsy in the management of suspected renal lym- phoma. Sheila Sheth, MD ● Syed Ali, MD ● Elliot Fishman, MD Extranodal spread of lymphoma often affects the genitourinary system, with the kidneys being the most commonly involved organs. Contrast material– enhanced computed tomography (CT) remains the modality of choice for the detection, diagnosis, staging, and monitoring of renal lymphoma. Magnetic resonance (MR) imaging is particularly useful in patients in whom intravenous administration of iodinated contrast ma- terial is contraindicated. Ultrasonography (US), although very valuable for diagnosing lymphoma in the testis or epididymis, is less sensitive than CT and MR imaging for detecting renal lymphoma. Typical im- aging findings of renal lymphoma include multiple poorly enhancing or hypoechoic masses, retroperitoneal tumors directly invading the kid- neys, bilateral renal enlargement, and perirenal soft-tissue masses. Cys- tic lesions and tumors predominantly affecting the renal sinus and col- lecting system are uncommon. Unless the renal lesions manifest in the setting of widespread lymphoma, percutaneous biopsy is indicated to differentiate lymphoma from metastases, hypovascular renal cell carci- noma, uroepithelial carcinoma, or atypical infection, with US routinely being used to guide the procedure. Current immunohistochemical techniques allow accurate diagnosis and characterization of renal lym- phoma. Radiologists should be familiar with both typical and atypical manifestations of renal lymphoma and should recommend imaging- guided percutaneous biopsy for diagnostic confirmation to avoid un- necessary nephrectomy. © RSNA, 2006 Abbreviations: FDG = fluorodeoxyglucose, H-E = hematoxylin-eosin, HIV = human immunodeficiency virus RadioGraphics 2006; 26:1151–1168 ● Published online 10.1148/rg.264055125 ● Content Codes: 1 From the Russell H. Morgan Department of Radiology and Radiological Science (S.S., E.F.) and the Department of Pathology (S.A.), Johns Hopkins University, 600 N Wolfe St, Baltimore, MD 21287. Presented as an education exhibit at the 2004 RSNA Annual Meeting. Received May 31, 2005; revision requested June 24 and received July 27; accepted August 4. All authors have no financial relationships to disclose. Address correspondence to S.S. (e-mail: ssheth@jhmi.edu). © RSNA, 2006 RadioGraphics CME FEATURE See accompanying test at http:// www.rsna.org /education /rg_cme.html See last page TEACHING POINTS 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.