DisseminatedTrichosporon beigelii infection in patients with malignant diseases: Immunohistochemical study and review

Trichosporon beigelii is a causative agent of opportunistic infection and summer-type hypersensitivity pneumonitis in Japan. However, as the diagnosis ofTrichosporon beigelii infection is sometimes difficult, the actual incidence of this disease may be underestimated. Of 203 autopsy patients with malignant disease, seven (7.7 %) were diagnosed with disseminatedTrichosporon beigelii infection by immunohistochemical investigation of formalin-fixed, paraffin-embedded tissue sections. Including these seven, a total of 43 patients withTrichosporon beigelii infection have been reported in Japan. The majority of them had underlying hematologic malignancies, for which they received cytotoxic chemotherapy resulting in neutropenia. This study indicates that the immunohistochemical method, which can be applied to biopsy specimens, is an excellent tool for specific diagnosis ofTrichosporon beigelii infection, which is an emerging fatal mycosis in immunocompromised patients with profound neutropenia.