A 65-year-old man with a history of hypertension presents to the emergency department with sudden onset of tearing chest pain radiating to the back. CT angiography reveals a dissecting hematoma within the media of the aorta extending from the aortic root to the descending thoracic aorta. Histology of the aortic wall shows loss of smooth muscle cells and elastic fibers in the media with pooling of basophilic ground substance. What is this histological finding called?
- A Mönckeberg medial calcific sclerosis
- B Granulomatous aortitis with giant cells
- C Cystic medial degeneration (cystic medial necrosis) ✓
- D Obliterative endarteritis of the vasa vasorum
Explanation
Cystic medial degeneration (also called cystic medial necrosis) describes the accumulation of mucopolysaccharide ground substance, loss of smooth muscle cells, and fragmentation of elastic lamellae in the aortic media, creating cleft-like spaces. This is the characteristic histological substrate for aortic dissection and is seen both in hypertension and inherited connective tissue disorders (Marfan syndrome, Ehlers-Danlos type IV). Granulomatous aortitis (giant cell or Takayasu) causes aortic wall thickening; obliterative endarteritis of vasa vasorum is a feature of syphilitic aortitis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.