Cerebral phaeohyphomycosis: The 'Dark Side' of fungal infections.

Purpose: Cerebral phaeohyphomycosis is a rare and fatal fungal infection of the central nervous system (CNS) caused by dematiaceous fungi. The aim of this study was to analyse the clinico- radiological presentation, pathology and outcome of cerebral phaeohyphomycosis and discuss the relevant literature.
Patients and Methods: Data of 7 patients diagnosed with cerebral phaeohyphomycosis and managed at our institute between 2014 and 2020 was collected and reviewed retrospectively. The diagnosis was established after surgery on KOH mount, Sabouraud dextrose agar, frozen section or histopathology. The clinical, radiological and pathological characteristics along with outcomes were analysed.
Results: Three patients with underlying comorbidities [chronic renal failure-2 and haematological malignancy -1] presented with brain abscess. The remaining 4 had no comorbidities. Two of them mimicked cystic glioma and one patient presented as intraventricular tumour. Another patient on anti- tubercular treatment for suspected pulmonary tuberculosis presented with encephalitis. Histopathology in all patients showed diffuse micro abscesses with coarse and reactive gliosis in the adjacent brain parenchyma and chronic lymphomononuclear inflammation without angioinvasion or vasculitis. Four showed granuloma formation. Antifungals were started after diagnosis. Six out of seven patients died and one was lost to follow up.
Conclusion: Cerebral phaeohyphomycosis presents as abscesses in immunocompromised patients and mimics tumours in immunocompetent patients. KOH mount and frozen section examination is simple yet effective tool for establishing early diagnosis. Overall, the prognosis is dismal. Administering antifungals early in the course of management along with aggressive surgical excision may improve outcomes.
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