A 32-year-old woman has resistant hypertension despite three drugs. There is a faint epigastric bruit. Catheter angiography shows bilateral mid-to-distal renal artery narrowing with alternating stenoses and dilations giving a string of beads appearance. The histological subtype and affected layer are:

• A Intimal fibroplasia of the tunica intima
• B Adventitial fibroplasia of the tunica adventitia
• C Perimedial fibroplasia of the outer media
• D Medial fibromuscular dysplasia of the tunica media ✓

Explanation

The string of beads sign in a young woman with hypertension is classic for fibromuscular dysplasia of the renal arteries. The most common variant, accounting for the majority of cases, is medial fibroplasia with alternating thickened fibromuscular ridges and thinned media lacking an internal elastic lamina in the ridges. It spares the ostium, unlike atherosclerotic renovascular disease, which affects the proximal third and explains why that condition is excluded here.

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.