A 55-year-old male with diabetic ketoacidosis presents with black necrotic eschar on the nasal mucosa, proptosis, and ophthalmoplegia. A clinical diagnosis of mucormycosis is made. What is the key pathophysiological mechanism responsible for the tissue necrosis and vascular invasion seen in this condition?
- A Granulomatous inflammation causing tissue destruction
- B Angioinvasion with arterial thrombosis and tissue infarction ✓
- C Direct eosinophilic tissue invasion via Charcot-Leyden crystals
- D Complement-mediated vasculitis of small vessels
Correct answer: B. Angioinvasion with arterial thrombosis and tissue infarction
Explanation
Mucormycosis is characterized by fungal angioinvasion by broad, aseptate hyphae with right-angle branching. The organisms invade arterial walls causing thrombosis, ischemia, and tissue infarction, producing the characteristic black necrotic eschar. This explains the rapid progression and need for aggressive surgical debridement. Option C describes allergic fungal sinusitis, not mucormycosis. Robbins 10th edition, Chapter 8.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
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Written and medically reviewed by the StethoPrep medical team.