A 25-year-old woman is found to have a mid-systolic click followed by a late systolic murmur at the apex. Echocardiography shows billowing of the mitral valve leaflets into the left atrium during systole. What is the characteristic histological abnormality in the valve leaflets?
- A Myxomatous degeneration with accumulation of mucopolysaccharides ✓
- B Fibrinoid necrosis of the valve ring
- C Caseating granulomas with Langhans giant cells
- D Fibrous thickening with neovascularization and chronic inflammation
Correct answer: A. Myxomatous degeneration with accumulation of mucopolysaccharides
Explanation
Mitral valve prolapse is caused by myxomatous degeneration of the valve leaflets, characterized by accumulation of mucopolysaccharides (acid mucopolysaccharide ground substance) within the spongiosa layer, causing thickening and redundancy of the leaflets. This is the most common cause of isolated mitral regurgitation in young women. Fibrous thickening with neovascularization describes chronic rheumatic valve disease. Robbins 10th ed, Chapter 12.
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.