A neutropenic patient post-bone marrow transplantation develops fever with pulmonary infiltrates. Bronchoalveolar lavage shows broad, ribbon-like non-septate (pauci-septate) hyphae branching at right angles. CT shows perihilar infiltrates with a tendency for vascular invasion. The most likely diagnosis is:
- A Invasive aspergillosis
- B Mucormycosis ✓
- C Cryptococcosis
- D Candida pneumonia
Explanation
Mucormycosis (caused by Mucor, Rhizopus, Cunninghamella, and related organisms of order Mucorales) is characterized by broad, ribbon-like, pauci-septate (rarely or non-septate) hyphae with irregular wide-angle (90-degree) branching on histology or BAL. In contrast, Aspergillus shows narrow, uniform, septate hyphae branching at 45-degree acute angles. Mucormycosis has a strong predilection for vascular invasion causing thrombosis and infarction ('angio-invasive'). Risk factors include neutropenia, poorly controlled diabetes (especially ketoacidosis), and iron overload. Liposomal amphotericin B is the treatment of choice.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.