Mycotic infections of the inner ear

Mycotic infections of the inner ear have only rarely been reported. In each reported case, involvement of the inner ear appeared to be secondary to overwhelming central nervous system disease. A review of specimens from the University of Minnesota temporal bone collection has identified three distinct routes of inner ear involvement by fungi suggesting the potential pathogenesis for this disease to be similar to that identified for bacterial labyrinthitis (tympanogenic, meningogenic, hematogenic). The first case, a 48-year-old white male with leukemia, died of mucor meningoencephalitis. Temporal bone study revealed Mucor sp. in the arterioles of the temporal bone as well as fungal involvement of the perilymphatic space secondary to round window invasion, oval window invasion, and invasion through the internal auditory canal. The second case was a 69-year-old white male, diabetic, who died of Klebsiella septicemia. Post mortem temporal bone study revealed a focus of Candida sp. in the vestibule under the stapedial footplate without apparent involvement of the internal auditory canal. Case 3 was a 16-year-old male with lymphosarcoma who died of septicemia and candida meningoencephalitis. Candida sp. could be seen in the scala tympani adjacent to Rosenthal's canals presumably secondary to spread from the central nervous system. The fourth case, that of a 28-year-old white female with systemic candidiasis, had sequential ante mortem audiograms demonstrating progressive bilateral sensorineural hearing loss. Post mortem histologic examination of the temporal bones identified Candida involvement of the inner ear which appeared to be hematogenic in origin. These four cases demonstrate conclusive examples of inner ear involvement of fungal disease by the tympanogenic, meningogenic, and hematogenic routes.