Coexistent localized primary renal lymphoma within renal cell carcinoma in the native kidney of a kidney transplant recipient: A case report

The coexistence of two different malignancies in one site is rare. Development of renal cell carcinoma (RCC) and lymphoma in the same individual is speculated to be due to common immune mechanism and/or genetic predisposition. We report a tumor comprising RCC and localized primary renal diffuse large B-cell lymphoma (DLBCL) in the native kidney of a 53-year-old kidney transplant recipient after 15 years of transplant. Patient had stable renal function on tacrolimus, mycophenolate mofetil (MMF) and prednisolone. On a trauma pan scan (as he reported after an assault), the left kidney was seen to be completely replaced by a mass. There was no imaging evidence of metastasis. A radical left nephrectomy was performed. Pathology showed clear cell RCC and a focus of DLBCL within the tumor which was staged 1E. EBV antigen in the tumor was negative. He was treated with three cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) as adjuvant therapy. MMF was withheld during chemotherapy and he continued to be on tacrolimus and prednisone. He remains disease-free 2 years after treatment. Our patient presents challenges that arise in managing two different tumors within the same site in an immunosuppressed individual at risk of relapse.