Cerebral phaeohyphomycosis at a tertiary healthcare center in Saudi Arabia

Abstract

Objectives: To report cases of cerebral phaeohyphomycosis at a tertiary hospital in Riyadh, Saudi Arabia. Phaeohyphomycetes are a widely distributed group of fungi whose cell walls contain 1,8 dihydroxynaphthalene-melanin. Cerebral infections caused by these fungi are uncommon and primarily associated with neurotrophic phaeohyphomycetes.

Methods: In January of 2020 we looked back to identify cases of culture-positive cerebral phaeohyphomycosis from our medical records at King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia. Data on demographics, potential risk factors, clinical presentation, treatment, and outcomes were analyzed.

Results: Twelve cases of cerebral phaeohyphomycosis were identified, of which 4 were caused by Rhinocladiella mackenziei and the other 8 were caused by various phaeohyphomycetes. There were 2 cases caused by Neoscytalidium dimidiatum, and one case each caused by the following: Acrophialophora fusispora, Chaetomium atrobrunneum, Exophiala dermatitidis, Exerohilum rostratum, Fonsecaea pedrosoi, and Cladophialophora bantiana. Most patients (10 of 12) had underlying immunosuppression. R. mackenziei caused a brain-only infection manifesting as abscess formation. Four patients survived for more than a year after therapy. Surgical evacuation and triazole therapy with posaconazole or itraconazole, alone or in combination with other antifungal agents, were associated with success.

Conclusion: Cerebral phaeohyphomycosis is an uncommon fungal infection that primarily affects immunocompromised patients and is associated with poor prognosis. R. mackenziei is the most prevalent fungus in our facility and has been linked to a universal mortality.

Figure 1

- Radiographic, ventriculoscopic, and histopathological morphologies of Cladophialophora bantiana A) A patient with hydrocephalus due to a brain infection caused by Cladophialophora bantiana. B) Ventriculoscopy revealed extensive ventriculitis, with fungus incorporating the lateral ventricles (arrows). C) Gomori methenamine silver histopathology stain of the brain revealed septate hyphae, and D) fungal culture revealed the characteristic morphology of C. bantiana.