A patient dies 4 days after an acute anterior myocardial infarction. At autopsy, the infarct zone shows yellow softening with a red hyperemic border. On microscopy, which combination of findings is expected?

• A Contraction band necrosis with interstitial hemorrhage and marginal macrophages
• B Waviness of myofibers at periphery with interstitial edema and minimal inflammation
• C Coagulative necrosis with ghost outlines, neutrophilic infiltrate, and early granulation tissue at margins ✓
• D Granulation tissue replacing entire infarct with scattered lymphocytes

Explanation

At 3-7 days post-MI, coagulative necrosis with preservation of cell outlines (ghost cells) is the dominant finding. Neutrophilic infiltration peaks at 2-4 days; by day 4-5, macrophage ingress and early granulation tissue with capillary and fibroblast proliferation begin at the margins, creating the grossly visible red hyperemic border. Contraction band necrosis is seen in reperfused infarcts and catecholamine excess. Waviness of myofibers is the earliest change (6-12 hours). Granulation tissue replacing the entire infarct is a later finding (1-3 weeks).

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

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