Differential Diagnosis of Renal Tumors With Papillary ArchitectureTickoo, Satish K. MD*; Reuter, Victor E. MD*,†Advances in Anatomic Pathology: March 2011 - Volume 18 - Issue 2 - p 120–131 doi: 10.1097/PAP.0b013e31820cb3dd Review Articles Abstract Author Information Papillary renal cell carcinoma is the second most common malignant renal epithelial tumor and constitutes approximately 15% of renal cell tumors. However, papillary architecture is neither unique to papillary renal cell carcinoma, nor do all papillary renal cell carcinomas show exclusive papillary histology. Many of the nonpapillary renal cell carcinomas with papillary architecture have been recognized only recently. Distinction of these from papillary renal cell carcinoma is essential, as biologic behavior and potential therapeutic options are distinct in many such tumors. Close attention to the cytologic and growth pattern characteristics will allow us to arrive at the proper diagnosis in most cases, although sometimes immunohistochemistry and rarely genetic evaluation may be needed. *Department of Pathology, Memorial Sloan-Kettering Cancer Center †Department of Pathology, Weill Medical College of Cornell University, New York, NY Reprints: Satish K. Tickoo, MD, Department of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 (e-mail: firstname.lastname@example.org). Copyright © 2011 Wolters Kluwer Health, Inc. All rights reserved.