RESUMEN
BACKGROUND: A 36-year-old, previously healthy man presented to an accident and emergency department with right-sided abdominal pain 7 days after he sustained a trauma to his right flank. He was using no medication other than over-the-counter analgesics since his injury. INVESTIGATIONS: Complete blood count, serum creatinine measurement, liver function tests, hepatitis B and C screening, abdominal CT, renal angiography, surgical exploration and histology of kidney samples. DIAGNOSIS: Polyarteritis nodosa with Page kidney causing bilateral perirenal hematoma, severe hypertension and renal failure. MANAGEMENT: The patient was severely anemic, and his bleeding was investigated. A 15 x 13 x 12 cm retroperitoneal hematoma was found in the region of the right kidney and the patient underwent unilateral right nephrectomy. 3 weeks after discharge the patient was readmitted with a left-sided perirenal hematoma. Steel-coil embolization of the kidney stopped the bleeding but the patient developed hypertension and renal failure, and antihypertensive agents and dialysis were started. Microaneurysms and vessel-wall necrosis were discovered on re-examination of the angiogram and histology, respectively, so immunosuppressive therapy was started, comprising intravenous methylprednisolone daily for 3 days and oral prednisolone and intravenous cyclophosphamide for 4 weeks. Page kidney, resulting from the bleeding into the solitary kidney, caused stretching of the renal artery and deterioration of renal function, which required hemodialysis treatment.