Replacement Kidney Lipomatosis After Renal Transplantation

Abstract

Renal sinus lipomatosis consists of abnormal fatty proliferation of the renal sinus, hilus, and perirenal spaces. Its pathogenesis is unknown, although it is generally associated with aging, renal atrophy, and long-standing chronic inflammation or urinary tract infection. Although this condition is rare, it may be important to recognize it in renal transplant recipients. We describe three cases of replacement kidney lipomatosis that occurred after cadaveric renal transplantation and discuss the possible differential diagnosis of this condition.

Allograft dysfunction in a patient with an odd-looking kidney: case of renal lipomatosis and review of literature

“…Other possible risk factors include aging, obesity, atherosclerosis [ 7 ] and chronic urinary tract infection [ 1 ]. Lipomatosis in the transplant kidney had been reported within 6 months to 8 years of transplantation [ 8 ]. In the case of our patient, her renal lipomatosis was detected 7 years after transplantation.…”

Renal Sinus Lipomatosis in Transplanted Kidneys: An Unusual Clinical Case

“…The discovery of RSL represents an uncommon finding of renal US either in normal subjects and in transplant recipients; indeed, there are just two papers describing RSL or RRL in these latter patients [4, 5], despite the accurate and prolonged radiological followup of transplanted organs. At difference with previous reports, here we describe a peculiar case of RSL characterised by its huge dimension, the onset of acute renal dysfunction, and its “paradoxical” resolution.…”

“…Therefore, the described association between RSL and pulse therapy of rejections could simply reflect a higher degree of inflammation. A study of Laouad et al describes 3 cases of RSL/RRL characterised by the presence of delayed graft function, recurrent urinary tract infections, and multiple rejection episodes, all proinflammatory episodes [5]. Whether other factors are involved in determining RSL beyond chronic inflammation remains obscure: a role for sirolimus in our patient, however, seems unlikely considering the well-known antiproliferative properties of such drug; at present no further report of RLS associated with sirolimus treatment has been published.…”

“…The patient refused these procedures. In the meantime, considering the clinical suspicion and what had been reported in a previous experience [5], we empirically decided to increase the dosage of methylprednisolone from 4 to 16 mg/day, postulating an acute inflammation either of the perirenal fat (of unknown origin) or of the ureter (passage of a renal stone?) able to determine a functional obstruction.…”

“…The presence of RSL in a renal transplant recipient was described for the first time in 1979 [4], and, since then, only three additional cases have been mentioned in 2005 [5], although described as RRL. We report a peculiar clinical case of RSL, characterised by a huge dimension and by acute renal impairment, never described to date, with recovery of renal function after steroid treatment.…”