Mucormycosis laboratory findings
When a clinician suspects invasive mucormycosis infection, an early diagnostic procedure performed within 16 days from the onset of symptom and early initiation of antifungal therapy will lead to successful management of this highly fatal disease. Biopsy with H&E staining of the specimen and PCR may confirm the diagnosis in suspected cases.
Findings on Hemotoxylin and Eosin (H&E) sections
- Subcutaneous lesions show aseptate hyphae immersed in an intense acute inflammatory exudate of neutrophils, eosinophils and fibrosis.
- Focal collections of epithelioid and Langhans multinucleated giant cells are also observed.
- Mucor spp. typically are rapid growing, producing globose sporangia on sporangiophores that are either solitary or branched.
- The sporangia contain the entire columella and spores that are mucus bound.
- The sporangial wall collapses irregularly, if at all.
- Rhizoids and stolons are absent. These features distinguish the Mucor spp. from the other producers of globose sporangia.
Findings on PCR analysis
- Detection of fungal DNA from biopsy specimens allows rapid identification of the causative organism of mucormycosis.
- Mucorales quantitative PCR not only confirm the mucormycosis diagnosis when other mycological arguments were present but could also anticipate this diagnosis.
- Quantification of DNA loads may also be a useful adjunct to treatment monitoring.
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