Spontaneous perirenal hematoma due to multiple renal artery aneurysms in a patient with presumed polyarteritis nodosa

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that involves the renal and visceral arteries. ¹ PAN typically presents with systemic symptoms and signs such as fatigue, weight loss, weakness, fever, arthralgia, skin lesions, hypertension, renal insufficiency, neurologic dysfunction and abdominal pain. ² Despite the common involvement of the kidney, spontaneous perirenal hemorrhage from a renal vasculitic aneurysm is a rare complication.

A 72-year-old man was admitted to the hospital with complaints of dyspnea and generalized edema that had persisted for 2 weeks. Physical examination revealed coarse and decreased breath sounds with moist rales. His serum potassium and creatinine level were 9.5 mEq/L and 10.6 mg/dL, respectively. Viral makers and autoantibodies, including anti-neutrophil cytoplasmic antibodies, were negative. His erythrocyte sedimentation rate was 18 mm/h and high sensitive C-reactive protein was 21.4 mg/L. We performed emergency hemodialysis via femoral vein catheterization under the impression of acute kidney injury and uncontrollable potassium levels. After emergency dialysis, the patient’s condition slowly improved. On the 15th hospital day, he complained of a sudden onset of right flank pain accompanied by a hypotensive episode. Abdominal computed tomography showed massive perirenal hematoma around the right kidney (Panel A: arrow). Renal angiography showed multiple aneurysmal dilatations of the interlobar arteries of the right kidney, and we performed coil embolization (Panel B: arrows; Panel C). Polyarteritis nodosa was diagnosed according to the radiologic findings of aneurysmal dilatation of the interlobar arteries of the right kidney.

OPEN IN VIEWER Panel A

OPEN IN VIEWER Panel B

OPEN IN VIEWER Panel C

In the absence of easily accessible tissue for biopsy, the angiographic demonstration of involved vessels is helpful for diagnosing vasculitis, particularly in the renal, hepatic, and visceral arteries. ³ In this case, we did not consider PAN before performing renal angiography due to the absence of the typical clinical presentation and laboratory testing. Because of dyspnea and pulmonary edema on chest X-ray, we did not consider the invasive renal biopsy. After the patient presented with perirenal hematoma, the diagnosis was established by renal angiography. Therefore, renal angiography may be helpful to establish the etiology of perirenal hematoma of unknown cause.