Fungi of the order Mucorales can invade the cribriform plate, leading to rhinocerebral mucormycosis in susceptible individuals.

• A. Mucorales
• B. Aspergillus
• C. Cryptococcus
• D. Candida

Answer: (A)

Fungi in the Mucorales are classic opportunistic pathogens that cause rhinocerebral mucormycosis by invading through the nasal passages and paranasal sinuses and then extending directly through the skull base, often via the cribriform plate, into the brain. This angioinvasive infection is most common in susceptible individuals, such as those with diabetic ketoacidosis or other immune compromises, and it progresses rapidly with tissue necrosis from vascular invasion. A key microscopic feature is broad, nonseptate or sparsely septate hyphae with wide-angle (often near 90-degree) branching, which helps distinguish Mucorales from other fungi. In contrast, Aspergillus has septate hyphae with acute-angle branching and tends to produce different patterns of invasive disease; Cryptococcus is a encapsulated yeast causing meningitis or cryptococcomas, and Candida typically causes candidemia or localized infections rather than rhinocerebral invasion.