Abstract
Background : Conidiobolus species are zygomycetous fungi known to cause localized nasopharyngeal infection in relatively healthy persons in the tropics. No human infections have previously been described in Japan. We encountered an autopsy case of disseminated human infection caused by Conidiobolus sp. and describe the cytological features of this fungus.
Case : The patient was a 61-year-old man who had received a hematopoietic stem cell transplant because of malignant lymphoma. Two months later, he developed pneumonia and died of respiratory failure. Transbronchial aspiration cytology performed a day before death showed thin-walled hyphae branching at right angles or irregularly, consistent with the features of zygomycetes. Vesicular components were also seen. Some hyphae were septate and branched at 45°, consistent with the features of Aspergillus. Similar characteristics of hyphae were also found in histological sections of autopsied tissues. Culture examination identified the fungus as Conidiobolus.
Conclusion : In the cytology of conidiobolomycosis, the hyphae had features of both zygomycetes and Aspergillus. Careful attention shuld be paid to making the correct cytodiagnosis of fungal infection to avoid the usage of wrong antibiotics.
