Investigation into a post renal transplant nephrectomy mass—Sinister or benign?

We present a case report in which a suspicious mass was found in a 12-year-old cadaveric kidney transplant. Core biopsies of the mass revealed renal cell carcinoma and the allograft was explanted. Six months post-allograft nephrectomy, the patient presented with an infiltrative vascular mass in the surgical bed. Cancer cell seeding from previous intervention and surgery was suspected. Subsequent fine needle biopsies of the mass demonstrated inflammatory cells with some histiocytes but no evidence of malignancy. This case demonstrates the characteristic ability of inflammatory pseudotumor to mimic a malignant process. It also highlights the role of percutaneous tissue sampling in directing patient management with the avoidance of unnecessary surgery.