Wunderlich Syndrome Complicated by Page Kidney as the Initial Presentation of Polyarteritis Nodosa: A Rare Case Report

Abstract

Background: Wunderlich syndrome, characterized by spontaneous non-traumatic renal or perirenal hemorrhage, is a rare but potentially life-threatening condition. Polyarteritis Nodosa (PAN) infrequently presents with spontaneous renal hemorrhage, and the simultaneous occurrence of Page kidney physiology further adds to its diagnostic complexity. This case highlights an unusual initial manifestation of PAN with isolated renal involvement. Case Report: A 46-year-old man with well-controlled type 2 diabetes mellitus and systemic hypertension presented with acute dyspnea, giddiness, headache, and vague abdominal pain. On admission, he was in hypertensive emergency related pulmonary edema. Initial imaging demonstrated a right perirenal hematoma, and laboratory studies revealed renal failure, hypokalemia, and mild anemia. Despite stepwise escalation of antihypertensive therapy, his blood pressure remained refractory. Progressive anemia and worsening renal function prompted repeat imaging, which showed interval enlargement of the hematoma. CT renal angiography demonstrated perirenal, adrenal, and paravertebral hematomas, diffuse circumferential thickening of the renal arteries, and multiple microaneurysms—features highly suggestive of medium-vessel vasculitis. Serological testing confirmed hepatitis B surface antigen positivity and ANCA negativity. Based on clinical, radiologic, and serologic evidence, a diagnosis of Polyarteritis Nodosa presenting with Wunderlich syndrome and secondary Page kidney was established.The patient was managed with blood transfusions, steroids and cyclophosphamide-based immunosuppression, and optimized antihypertensive therapy. Renal function gradually improved, and clinical remission was achieved by three months. Conclusion: This case emphasizes the need to consider medium-vessel vasculitis as an underlying cause in patients presenting with spontaneous perirenal hemorrhage and refractory hypertension. Recognition of this association is crucial, as timely initiation of appropriate immunosuppressive therapy can halt disease progression, preserve renal function, and significantly improve patient outcomes.