A 60-year-old hypertensive patient develops a dissection of the ascending aorta. Pathology of the aortic wall shows loss of elastic lamellae, smooth muscle cell dropout, and accumulation of basophilic ground substance (proteoglycans) in the media. What is this pathological change and which connective tissue disease most specifically features this?
- A Atherosclerosis of the aortic wall — occurs in hypertensive patients with plaque rupture
- B Cystic medial necrosis (cystic medial degeneration) — occurs in Marfan syndrome and Loeys-Dietz syndrome due to FBN1/TGFBR2 mutations ✓
- C Granulomatous aortitis — occurs in Takayasu's arteritis
- D Necrotizing vasculitis — occurs in polyarteritis nodosa
Explanation
Cystic medial degeneration (Erdheim's mucoid medial degeneration) describes fragmentation and loss of elastic fibers with accumulation of glycosaminoglycans/proteoglycans in the aortic media and smooth muscle cell loss, without true cyst formation. This predisposes to aortic dissection and aneurysm. It is the characteristic pathological finding in Marfan syndrome (FBN1 mutation causing dysregulated TGF-β signaling) and Loeys-Dietz syndrome (TGFBR1/2 mutations). It is also seen in isolated familial thoracic aortic aneurysm/dissection and, to a lesser extent, in hypertension.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.