Polyarteritis nodosa presenting as haematuria following strenuous exercise

Abstract

Polyarteritis nodosa (PAN) can affect many organ systems but usually presents with a systemic illness characterised by malaise, weight loss, myalgia, arthralgia and signs of end-organ damage. Here, we report a case of PAN that presented acutely in a previously well 46-year-old man with visible haematuria and loin pain coinciding with an episode of strenuous exercise. Initially, the patient was thought to have suffered renal trauma, but subsequent investigations revealed intrarenal aneurysms typical of PAN which responded to immunosuppressive therapy. This case illustrates the importance of appropriate imaging for suspected urogenital tract trauma, that a high index of suspicion is required to make the diagnosis and that PAN can present with renal tract bleeding in the absence of obvious systemic features.

Figure 1

(A) Initial delayed CT 2.5 h postcontrast. Coronal MPR (multiplanar reconstruction) image. The left pelvicalyceal system contains a cast of clot. There is a markedly delayed left-sided nephrogram, in keeping with significant obstruction (compare to the unobstructed right kidney). No contrast extravasation was seen. (B) CT angiogram on day 7 postinitial presentation. Oblique maximum intensity projection image showing a false aneurysm at the lower pole of the left kidney as well as the proximal pigtail of the ureteric stent. Despite the stent, the kidney remains hydronephrotic. A cast of clot is seen within the pelvicalyceal system.

Figure 2

(A) Renal angiogram on day 10 postinitial presentation. Image of right kidney showing beading of the arterial branches in keeping with microaneurysms. (B) Repeat non-selective left-renal angiogram on day 10 postinitial presentation. The vessel feeding the false aneurysm has now been embolised with a nest of platinum coils. Renal arteries are end arteries so there will be no collateral supply that could continue to feed the false aneurysm. The aneurysm is no longer seen. (C) Follow-up CT angiogram 4 months postpresentation. Coronal maximum intensity projection image showing embolisation coils and associated streak artefact in the lower pole of the left kidney. The false aneurysm is no longer seen. The multiple right renal microaneurysms have resolved.