A 32-year-old woman with newly detected hypertension has an abdominal bruit. Doppler studies show right renal artery stenosis, and angiography reveals alternating stenosis and dilatation producing a string-of-beads pattern in the mid to distal renal artery. The underlying pathology is:

• A Atherosclerotic plaque at the renal artery ostium
• B Amyloid deposition in the renal arterial wall
• C Granulomatous panarteritis of the renal artery
• D Fibromuscular dysplasia, medial fibroplasia type, with ridges of smooth muscle and fibrous tissue alternating with thinned media ✓

Explanation

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory developmental anomaly of medium-sized arteries, most often the renal and carotid arteries, typically affecting young women. The commonest form is medial fibroplasia, where alternate areas of thickened media with smooth muscle and fibrous tissue and thinned media produce the string-of-beads angiographic appearance. Atherosclerotic renal artery stenosis occurs in older patients and involves the ostium or proximal third, not the mid to distal artery with beads.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.