At autopsy of a patient with long-standing rheumatic mitral disease, a well-demarcated area of endocardial thickening and fibrosis is found on the posterior wall of the left atrium above the mitral valve. This lesion is known as:

• A MacCallum patch ✓
• B Aschoff plaque
• C McCallum aneurysm
• D Jet lesion of infective endocarditis

Explanation

The MacCallum patch is a zone of subendocardial fibrosis and thickening on the posterior left atrial wall above the posterior mitral leaflet. It forms where the regurgitant jet of mitral insufficiency strikes the atrial wall, damaging the endocardium and provoking organization and fibrosis. It is characteristic of chronic rheumatic heart disease. Aschoff bodies are granulomas of active carditis and are not found in the chronic burned-out stage, and jet lesions from infective endocarditis lack the specific location and association with rheumatic deformity.

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.