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Case Reports in Transplantation
Volume 2011, Article ID 161759, 3 pages
Case Report

Renal Sinus Lipomatosis in Transplanted Kidneys: An Unusual Clinical Case

1Nephrology and Renal Transplantation, Department of Systematic Pathology, University of Naples “Federico II”, 80131 Naples, Italy
2Department of Radiology, University of Naples “Federico II”, Via S. Pansini 5, 80131 Naples, Italy

Received 4 November 2011; Accepted 18 December 2011

Academic Editor: R. K. Wali

Copyright © 2011 Luca Apicella et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Renal sinus lipomatosis (RSL) represents an abnormal proliferation of the adipose tissue surrounding the renal pelvis of uncertain origin, associated with aging, obesity, steroid excess, infections, and calculosis. It represents a rare complication in transplanted kidneys, and, despite the accurate and prolonged radiological followup of transplanted organs, only a few cases of RSL have been described in graft recipients, with no remarkable effects on renal function. The diagnosis relies on ultrasonography (US), magnetic resonance imaging (MRI), computed tomography (CT), and, finally, percutaneous biopsy. We describe the case of an extensive RSL in a 38-year-old renal transplant recipient, diagnosed by ultrasonography and computed tomography. The patient underwent a radiologic study because of an acute, asymptomatic renal impairment, that led to the diagnosis of a RSL of unusual dimensions, associated with a discrete hydronephrosis. Paradoxically, after a short course of steroids, the recovery of renal function and the partial resolution of calyceal dilatation were observed. The rarity of this affection, the need of a differential diagnosis with fat-containing tumors, and the possibility of parenchymal inflammation associated with RSL, potentially responsive to steroids, are also discussed.