Abstract Kidney transplantation is the treatment of choice for patients with end-stage kidney disease (ESKD) on renal dialysis, and is associated with cancers, cardiovascular diseases and infections attributed to the usage of immunosuppressive drugs. A wide variety of cancers across a number of organs occur with substantially increased incidence after renal transplant. Most studies show that cancer risk is the greatest for viral-related malignancies. There is increased risk of native kidney malignancy among transplant recipients compared with the general population. We present a case of a 34-year-old young male patient who presented with papillary renal cell carcinoma (PRCC) in the native kidney 5 years post- renal transplantation. Keywords: Renal cell carcinoma, Renal transplant. Introduction Kidney transplantation is the treatment of choice for patients with end-stage kidney disease (ESKD) on renal dialysis, and is associated with cancers, cardiovascular diseases and infections attributed to the usage of immunosuppressive drugs. Literature shows that the aetiology is multifactorial, but prolonged and intensive use of immunosuppressant drugs in transplant patients leads to alteration of immune function and immune surveillance and is associated with increased risk of cancer. 1-3 Other studies show that there is uncertainty as to whether the increased risk is due to immune suppression or related to pre-existing cancer risk factors or factors related to ESKD or dialysis. A wide variety of cancers across a number of organs occur with substantially increased incidence after renal transplant. Most studies show that the cancer risk is the greatest for viral-related malignancies. For example, cancers related to human papilloma virus (HPV), human herpes virus 8 (HHV-8), Epstein-Barr virus (EBV), and hepatitis B and C (HBV and HCV) viruses have a high risk in renal transplant recipients, whereas non-viral common epithelial cancers, such as breast and prostate cancers, occur at the same rate as general population. 2,3 The risk of Kaposi's sarcoma related to HHV-8 is more than 200 times in renal transplant recipients compared to the general population. The likely cause of increased incidence of virus-associated cancers is uraemic immune dysfunction supported by the evidence of re-activation of latent EBV infection in uraemic immunodeficiency. 3 Non-Hodgkin's lymphoma (NHL) and non-melanocytic skin cancers are the most common ones in renal transplant recipients; squamous cell carcinoma (SCC) occurs 25 times more frequently in the transplant population than the general population. 1 Malignancies of the genitourinary tract account for 15% of all the malignant tumours in the Cincinnati Tumour Transplant Register and the carcinoma of the native kidney accounts for up to 5% of all malignancies found in transplant recipients. 4 The 10-year risk of developing a solid malignancy is 20% for kidney transplant recipients. 5 One study reported a 100-fold increased risk of native kidney malignancy among transplant recipients compared with the general population. 6 Case Report A 34-year-old young male patient presented at Al-Hada Military Hospital, Taif, Saudi Arabia, with complaint of pain in the right loin for the preceding 3-4 months. He was a known case of chronic renal failure and had renal transplant done 5 years ago. He remained on dialysis three years prior to the transplant. There was no history of hypertension and diabetes mellitus. There was no history of dysuria. The patient was also on immunosuppressive drugs and was taking cyclosporine, prednisolone, atenolol and amlodipine. The graft function was normal. His serum cyclosporine level was 1047.4 ng/ml. He had bilateral mastitis, and was HCV positive. On further investigation, his urine examination was normal and cultures were negative. Serum creatinine was 1.17mg/dl and urea was 46 mg/dl. Renal mass was seen in the right kidney on ultrasonographic examination. Magnetic resonance imaging (MRI) was done and T2-weighted coronal images at posterior and anterior planes showed renal graft in the right lower abdomen and both atrophied native kidneys with isointense solid renal mass at lower pole of the right native kidney measuring 3 x 2.5 cm, in addition to tiny Vol. 63, No. 8, August 2013 1053 CASE REPORT Papillary Renal Cell Carcinoma in a patient with renal transplant Nausheen Yaqoob, 1 Kanwal Aftab, 2 Moemen Hafiz, 3 Qasim Raza, 4 Dalal Nemenqani 5 1-3,5 Department of Pathology, 4 Department of Radiology, King Abdul Aziz Specialist Hospital, Taif, Kingdom of Saudi Arabia. Correspondence: Nausheen Yaqoob. Email: nausheen_yaqoob@hotmail.com