Cerebral phaeohyphomycosis in an immunocompetent patient: a case report and literature summary

First case of subcutaneous cystic phaeohyphomycosis due to Phialophora chinensis in a kidney transplant recipient in Martinique

We report a case of subcutaneous mycosis in the form of a subcutaneous cyst of the index finger, successfully treated by surgery and posaconazole in an 84-year-old female kidney transplant patient. Intra-operative mycological analysis enabled the diagnosis of Phialophora chinensis phaeohyphomycosis. Phialophora chinensis is an environmental mold recently described in human pathology in cases of chromoblastomycosis. This is the first case of subcutaneous phaeohyphomycosis due to Phialophora chinensis in an immunocompromised patient.

Cerebral Phaeohyphomycosis Caused by Exophiala dermatitidis in a Chinese CARD9-Deficient Patient: A Case Report and Literature Review

Exophiala dermatitidis, a dematiaceous fungus typically found in decaying organic matter worldwide, is a rare cause of fungal infections. Cerebral phaeohyphomycosis is a sporadic but often fatal infection of the brain caused by E. dermatitidis. However, due to limited reports, little is known about its specific predisposing factors, clinical manifestation, and optimal treatment modality. Here, we report a clinical presentation and management of cerebral phaeohyphomycosis in a Chinese patient. An otherwise healthy, young male who was diagnosed with neck fungal lymphadenitis caused by E. dermatitidis 7 months prior and was treated with itraconazole, presented later with progressive intracranial hypertension and persistent coma. Culture of the neck lymphoid tissue produced growth of a black yeast-like fungus, which was identified as E. dermatitidis by sequencing of the ribosomal DNA internal transcribed spacer (ITS) domains. Accordingly, a cerebral biopsy was performed, and the pathological report showed mycelia and fungal granulomas. We also sequenced CARD9 in the patient and found him to be homozygous for loss-of-function mutation; his parents were heterozygous for the same mutation. This is a first case report of cerebral phaeohyphomycosis caused by E. dermatitidis in a CARD9-deficient Chinese patient. He eventually succumbed to brain herniation and severe lung infection with a poor response to therapy. Thus, previously healthy patients with unexplained invasive E. dermatitidis infection, at any age, should be tested for inherited CARD9 deficiency.