[Spontaneous retroperitoneal bleeding caused by rupture of the native kidney oncocytoma twelve years after renal transplantation].

Renal transplantation is the method of choice for renal replacement therapy in the majority of patients. Immunosuppressive drugs may increase the risk of developing malignancies. We present a case of a patient having undergone different renal replacement methods over 25 years. He had good graft function at 12 years of transplantation. Development of spontaneous retroperitoneal hematoma caused by rupture of the native kidney oncocytoma was complicated with sepsis and deterioration of graft function. We emphasize the importance of regular ultrasonography follow-up of native kidney, which is challenging because of fibrous changes.