RESUMEN
A 75-year-old man, highly suspected as having malignant lymphoma originating from his left testis, underwent exploratory orchiectomy for a definitive diagnosis. Laboratory examinations before the surgery showed high lactate dehydrogenase (652 IU/l), elevated serum creatinine level (1.85 mg/dl) and sIL-2R level (8,930 U/ml). As the postoperative course passed uneventfully, the patient was discharged from the hospital on the eighth day after the surgery. Ten days after the surgery the patient was transferred to the emergency room of the hospital complaining of severe abdominal pain and malaise. Laboratory examinations revealed highly elevated lactate dehydrogenase (2,807 IL/l), uric acid (24.9 mg/dl) and serum creatinine (5.31 mg/dl). Computed tomography demonstrated rapid growth of the retroperitoneal mass and occurrence of bilateral hydronephroses. Under the diagnosis of spontaneous tumor lysis syndrome, the patient was urgently treated with hemodialysis, steroidal pulse and rituximab following percutaneous nephrostomy for the right kidney. After improvement of the laboratory data, the patient was transferred to another hospital for the treatment of malignant lymphoma.