Fibromuscular dysplasia: a rare disease that can mimic vasculitis.

Fibromuscular dysplasia (FMD) is an uncommon angiopathy that occurs mainly in young to middle-aged female individuals. It is an idiopathic, segmental, non-inflammatory and non-atherosclerotic vascular disease leading to stenosis of small- and medium-sized arteries. Clinical manifestations are determined by the artery involved, most commonly hypertension (renal artery) and stroke (carotid artery). When FMD affects multiple vascular beds, it may mimic a systemic vasculitis. Here, we present the case of a young female patient with FMD. The patient had a clinical history of bilateral internal carotid artery dissection that required surgical repair. Since a systemic vascular disease was suspected, abdominal angiography was done, showing evidence of a "string of beads" appearance involving the distal two-thirds of the right renal artery. This lesion is considered to be pathognomonic of the medial FMD that accounts for 70-95% of all cases of FMD. Two years later, a new magnetic resonance angiography confirmed the "string of beads" appearance of the middle to distal part of the right renal artery, with significant hemodynamic stenosis that was successfully dilated with percutaneous transluminal angioplasty.