Intravenous Tamm-Horsfall Protein Polyps: Report of a Case in Association With a Hematoma That Mimicked a Renal Neoplasm  John P.T. Higgins, MD, Philip Huie, MS, Gilbert Rigaud, MD, Richard K. Sibley, MD  American Journal of Kidney Diseases  Volume 48, Issue 5, Pages e67-e71 (November 2006) DOI: 10.1053/j.ajkd.2006.08.014 Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 1 Computed tomographic scan of the abdomen showing left renal mass. *Cystic mass in the left kidney. American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 2 The margin of the mass. On the right, the mass consists of necrotic renal parenchyma with hemorrhage. This transitions into viable renal parenchyma on the left, from which it is not separated by a fibrous capsule. (Hematoxylin and eosin stain; original magnification ×40.) American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 3 Low-magnification view to show involvement of several veins by THP polyps. Several large-caliber veins are occluded partially or completely by fibrin and paucicellular mucoid material (arrows). An arcuate artery is unremarkable (*). (Hematoxylin and eosin stain; original magnification ×40.) American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 4 Arcuate vein containing THP polyp. Endothelium covers portions of the polyp adjacent to the residual lumen. (Hematoxylin and eosin stain; original magnification ×200.) American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 5 Immunohistochemical stain for THP in the renal medulla. Cytoplasmic staining of distal tubules confirms the specificity of the antibody for THP. (Hematoxylin counterstain; original magnification ×200.) American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions

Fig 6 (Left) Hematoxylin and eosin–stained section shows intravenous THP polyp. (Right) Immunohistochemical stain for THP highlights a venous polyp. THP also is abnormally present in Bowman space of the adjacent glomeruli. (Hematoxylin counterstain; original magnification ×200.) American Journal of Kidney Diseases 2006 48, e67-e71DOI: (10.1053/j.ajkd.2006.08.014) Copyright © 2006 National Kidney Foundation, Inc. Terms and Conditions