Mucormycosis - How to identify?

Mucormycosis 

Predisposing factors:

• Transplant recipients
• Uncontrolled diabetes mellitus
• Patients with hematological malignancies
• Immunosuppressed patients
• People living with HIV (PLHIV)

HOW TO IDENTIFY MUCORMYCOSIS:

Broad, aseptate fungal hyphae, branching at 90 degree.
Angioinvasion is frequently seen, leading to thrombosis of vessels and tissue infarction & necrosis.
Mucor is always seen as a basophilic "glassy" structure on H&E staining.

Pic shows fungal hyphae with right angled branching.

PAS and Silver Methanamine stain highlight the fungal hyphae.

Pic: PAS stain

Silver methanamine: Arrow points to the blood vessel, fungal hyphae are seen infiltrating the wall. 

DIFFERENTIAL DIAGNOSIS:
ASPERGILLUS:
Slender, septate hyphae with acute angle branching.


Note: Candida species is often seen with Mucor and Aspergillus.