INTRAVASCULAR PAPILLARY ENDOTHELIAL HYPERPLASIA IN A THROMBOSED RENAL-ALLOGRAFT VEIN

Intravascular papillary endothelial hyperplasia (LPEH) is a benign end othelial proliferation of unclear pathogenesis, usually associated wit h thrombus as an unusual mode of organization and occasionally coexist ing with vascular neoplasms, A 65-year-old white woman with chronic re nal disease caused by focal segmental glomerulosclerosis experienced t he failure of a cadaveric renal allograft 10 days after implantation. Pathological manifestations in the resected graft included total infar ction and thrombi in both the renal artery and vein, the latter of whi ch showed typical histopathologic features of IPEH, Papillary formatio ns with fibrinous cores lined by bland endothelial cells surrounded fr esh and organizing thrombus, and the proliferation had a highly cellul ar peripheral zone not readily recognizable as vascular, Immunohistoch emical stains for factor VIII, CD34, and in particular CD31, however, confirmed the nature of both the papillary and solid areas of the prol iferation as vascular endothelium. We present the first report of this lesion in an allograft vessel, and ive find its rapid development, in association with a thrombus of clinically discernable age, to be stro ng evidence supporting the hypothesis that IPEH represents an uncommon morphology of organizing thrombus. Copyright (C) 1996 by W.B. Saunder s Company