Unique imaging findings in fibromuscular dysplasia of renal arteries: A case report

RATIONALE: Fibromuscular dysplasia (FMD) is a rare vascular disorder that causes abnormal cell growth in arterial walls. The classic “string of beads” sign has been reported in many cases, whereas the appearance of tubular stenosis and distal tapering of renal arteries with multiple renal infarctions, as well as left kidney atrophy occurring in one patient, has not been precisely described. PATIENT CONCERNS: A 19-year-old woman presented to us with a history of elevated blood pressure without any symptoms for the past 1 month. Routine laboratory tests indicated a moderately impaired renal function, and ultrasound examination demonstrated a small-sized left kidney and seriously decreased blood flow of the left renal artery and its branches. DIAGNOSIS: Subsequent contrast-enhanced computed tomographic angiography (CTA) demonstrated multiple ischemic infarctions in the bilateral kidneys, and FMD was suggested at that time. Thereafter, we performed selective reno-angiography, which confirmed that the all left renal arteries had tubular stenosis and that right renal arterial branches presented distal tapering. INTERVENTION: Antihypertensive drugs were prescribed conservatively, including nifedipine 60 mg/d and prazosin 4 mg/d, to lower the patient's blood pressure. OUTCOMES: The patient had a well-controlled blood pressure and an improved renal function at her 6-month follow-up. LESSONS: We should take the diagnosis of FMD into account if young women develop asymptomatic hypertension. To our knowledge, this is the first case that exhibited renal artery FMD manifesting as tubular stenosis and distal tapering, especially followed by bilateral renal infarctions and significant atrophy of the left kidney. In addition, CTA combined with digital subtraction angiography (DSA) may be more sensitive than other tests with respect to the detection of intrarenal infarctions and arterial variants of FMD.