Aggressive angiomyxoma of transplanted kidney mimicking posttransplant lymphoproliferative disorder

Angiomyxoma is a scarce neoplasm arising from the soft tissues of perineum and pelvis, more commonly seen in the females. For such a tumor to arise in a renal allograft is rare and has previously been reported only in few case. We report a case of aggressive angiomyxoma arising de novo in the renal allograft nine-year posttransplantation. We describe its imaging features on ultrasound and computed tomography which closely mimic the more usual tumor of the transplanted kidney, posttransplant lymphoproliferative disorder and suggest that angiomyxoma may be considered as a differential diagnosis in a case of soft tissue mass arising within the renal allograft.