Teaching Case

Male patient in his 50s with malignant hypertension, high levels of normetanephrine. Patient recently treated with angiotensin-converting enzyme inhibitors, and admitted with an acute rise in renin levels. Routine CT of the abdomen was requested.

Fibromuscular dysplasia (FMD)  is a rare disease. It is characterised by a segmental arterial disease, which is neither atheromatous nor inflammatory. The exact cause is unknown. It affects smaller and to medium-sized arteries. Most commonly affected are renal arteries, second common are carotid arteries. However, it can occur in any artery in the body.

If symptomatic, patients often present with hypertension and symptoms related to hypertension (headaches, dizziness etc.). Some patients may also be asymptomatic, and the findings may be incidental. Up to 80-90% of cases are female, it is important not to “overlook” this diagnosis in male patients.

In the presented case the symptoms were hypertension and the explanation for this is seen in the left renal artery with a beaded appearance of the proximal artery. There are also aneurysms in the coeliac trunk and a dissection proximally in the coeliac trunk.

This should alert radiologists to the diagnosis of fibromuscular dysplasia with multivessel involvement [1]. Previously, this entity was called “visceral fibromuscular dysplasia”.  It has to be differentiated from simple renal arterial fibromuscular dysplasia, as the patient should be examined for carotid pathology, as carotid pathology may predispose to strokes [1]. Patients are treated with anti-platelets and anti-hypertensive drugs as a rule and may have to undergo endovascular intervention in more severe cases [1]. Another important differential diagnosis is “visceral artery dissection with normal-appearing arteries (VADNA)“[2]. This is a disease that mainly affects abdominal vessels and presents often with abdominal or flank pain, and this could have been the case if there had been no renal artery affection.