Diagnosis: Fibromuscular Arterial Dysplasia
• Fibromuscular arterial dysplasia (also termed renal artery dysplasia) is the most common cause for renovascular hypertension in young patients (usual age of presentation is in the second and third decades of life). It often affects women 25 to 50 years old and occurs in the distal two thirds of the renal artery and its major branches. Veins are not involved.
• Rarely, fibromuscular arterial dysplasia also can be seen in carotid, iliac, or abdominal arteries. The present case illustrates the typical clinical and radiographic presentation in a young woman presenting with persistent arterial hypertension.
• From a morphologic point of view, there are multiple forms of fibromuscular arterial dysplasia: intimal fibroplasia (rare), medial hyperplasia (rare), medial fibroplasia with aneurysms (common, 60% to 70%; bilateral in 60% of cases), perimedial fibroplasia (common, 15% to 25%), and adventitial fibroplasias (rare).
• The different morphologic patterns can show significant overlap. The most common and clinically significant variant is medial fibroplasia with segmental structural abnormalities of the medial smooth muscle layer including zones of medial collagen deposition alternating with normally developed arterial segments.
• Medial “scarring” results in aneurysm formation (60% to 70% of cases) and the typical radiologic appearance. Fibromuscular arterial dysplasia of the renal arteries often can be surgically corrected.
