Cerebral phaeohyphomycosis due to Rhinocladiella mackenziei (formerly Ramichloridium mackenziei): Case presentation and literature review

Abstract

Summary Rhinocladiella mackenziei (formerly Ramichloridium mackenziei), a causative agent of cerebral phaeohyphomycosis, is extremely rare and it is geographically limited to the Middle East. The organism has a predilection to cause brain infections and results in a grave prognosis with a high mortality rate. The current patient was admitted to a long term care facility with chronic respiratory failure and dependence on a mechanical ventilator. She later developed left sided weakness and a CT-scan of the brain revealed multiple variable sized hypodense, well-defined lesions with ring enhancement. A stereotactic needle aspiration of the largest lesion showed fungal hyphae. The final culture grew R. mackenzie. The patient was initially started on liposomal amphotericin B, then voriconazole and caspofungin intravenously as posaconazole was not available. The patient failed to respond to antifungal therapy and finally she died 34 days after the start of the treatment. R. mackenziei is a highly virulent agent, and should be considered in the differential diagnosis of central nervous system disease in patients from the Middle East.

Combination of Amphotericin B and Flucytosine against Neurotropic Species of Melanized Fungi Causing Primary Cerebral Phaeohyphomycosis

“…R. mackenziei causes cerebral infections mostly in debilitated patients, with a mortality rate of almost 100% if infections remain untreated; even in patients treated with surgery and antifungal therapy, mortality is almost 65%. This fungus is restricted to the Middle East, the Persian Gulf, Somalia, and Pakistan (2,40,41). E. dermatitidis is one of the most common clinically significant human pathogens in the black-yeast genus Exophiala, causing disseminated infection with a marked predilection for the central nervous system (CNS).…”

ESCMID and ECMM joint clinical guidelines for the diagnosis and management of systemic phaeohyphomycosis: diseases caused by black fungi

“…Cerebral abscess due to dematiaceous fungi is rare but frequently fatal and a surprisingly high proportion of these infections occurs in apparently immunocompetent individuals . These infections are spread haematogenously, probably from an initial, presumably subclinical pulmonary focus, although spread from the sinus or following surgery may also occur.…”

“…Although most infections with Exophiala dermatitidis are reported from East Asia the fungus is encountered worldwide. Overall, the therapeutic studies suggest that complete excision of brain abscesses has better outcome than only aspiration or partial excision (recommendation AII) . Even with antifungal therapy outcome is poor; however, single cases suggest that voriconazole and posaconazole may provide clinical improvement and voriconazole penetrates into brain tissue most effectively (recommendation CII) .…”

First fatal cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in Iran, based on ITS rDNA

“…The mortality rate of these infections is almost 100% despite aggressive antifungal and surgical therapy [5]. The infection is restricted largely to the Middle East, especially Saudi Arabia, Kuwait, Qatar and Afghanistan, although sporadic cases involving visitors or immigrants from endemic areas have been diagnosed in the UK and USA [3,12,14,15]. To the best of our knowledge, this patient represents the first case of R. mackenziei infection acquired in Iran (Middle East), which should be now considered as an endemic area.…”