Subcutaneous abscess due to the basidiomycete Phellinus mori in a patient with chronic granulomatous disease

Chronic granulomatous disease (CGD), a primary immunodeficiency caused by impaired phagocyte killing of intracellular pathogens, is characterized by recurrent, life-threatening, bacterial and fungal infections. As a result of improvements in microbiologic culture and identification techniques, a number of unique filamentous fungi have been reported as significant pathogens in patients with CGD. We report a case of subcutaneous basidiomycete Phellinus mori infection in a patient with CGD. To the best of our knowledge, this is the first reported case of human infection by this fungus. The causative fungus was identified on the basis of its morphological characteristics and nucleotide sequence on the internal transcribed spacer region of the ribosomal RNA gene. This is the fifth case report of filamentous basidiomycetes infecting a patient with CGD; all of these cases have been caused by Phellinus species. We highlight the importance of recognizing filamentous basidiomycetes Phellinus species as possible agents of non-Aspergillus fungal infections in patients with CGD.