Inflammatory pseudotumor of the kidney allograft.

Inflammatory myofibroblastic tumor, or inflammatory pseudotumor, usually is a benign lesion composed of mixed inflammatory and fibroblastic elements. It has rarely been reported in the posttransplantation setting and never in association with a renal allograft. Although the pathogenesis of this lesion is unclear, exposure to immunosuppressive agents and various infections have been implicated in its development. We report the first case of inflammatory myofibroblastic tumor infiltrating a renal allograft and highlight the role immunosuppression may have in the development of this lesion.