A 24-year-old tall, thin man with a midsystolic click and late systolic murmur undergoes valve surgery. Histology of the resected valve shows expansion of the spongiosa layer by loose myxomatous connective tissue with elongated chordae. What is the diagnosis?

• A Rheumatic mitral valve disease
• B Infective endocarditis with healed vegetations
• C Calcific mitral annular stenosis
• D Mitral valve prolapse with myxomatous degeneration ✓

Explanation

Mitral valve prolapse is caused by myxomatous degeneration in which the spongiosa layer expands with mucopolysaccharide-rich material, weakening the leaflets so they balloon into the atrium during systole. Chordae become elongated and thin, predisposing to rupture and acute severe regurgitation. Rheumatic valves show fibrous thickening and commissural fusion instead, annular calcification narrows the orifice without ballooning, and healed endocarditis leaves organized vegetations rather than diffuse myxoid change.

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.