Does one plus one always equal two?

Abstract

14 years after deceased-donor kidney transplantation, a 51-year-old man with stable graft function was shown to have an asymptomatic mass in his native kidney during annual ultrasonography in July, 2010. He had end stage renal disease secondary to glomerulonephritis. Post-transplant immunosuppression included ciclosporin, mycophenolic acid, and prednisone, without biological antibody therapy. The doses and blood concentrations of his immunosuppressants were at the mid to lower ends of standard practice. MRI showed a 7 cm right (native) renal tumour and 2·5 cm tumour in his transplant kidney. Radical right native nephrectomy and partial transplant nephrectomy were done uneventfully. Micro-scopically, both tumours were renal cell carcinoma (RCC) clear-cell type (pT1b in native kidney [fi gure A] and pT1a in transplant [fi gure B]) grade 3 Fuhrman nuclear grading (fi gure inserts). There were no microscopic cancer satellites beyond the capsules of the tumours, intravenous tumour thrombi, or metastasis in any of the 11 perihilar lymph nodes removed.To assess prognosis and further management we needed to know whether both tumours had formed de novo from the recipient’s and donor’s kidney or whether one was metastatic. If both were de novo, surgical excision was potentially curative (stage I RCC 5-year survival of about 81%).