First report of a Cryptococcus magnus infection in a cat.

This report describes an uncommon case of cryptococcosis in an apparently immunocompetent cat caused by Cryptococcus magnus. An amputation of the complete left foreleg and excision of the ipsilateral cervical lymph node were performed in a young-adult male Domestic Shorthair cat due to suspicion of a tumor. Granulomatous dermatitis, panniculitis, myositis, and lymphadenitis were diagnosed histologically. Intralesional, numerous round-to-ovoid yeast cells showing no capsule were detected within macrophages using special staining methods. The tissue material cultured on Sabouraud's glucose agar at 26°C yielded abundant growth of yeast colonies. Morphological, physiological, and molecular analyses of the yeasts demonstrated that the fungus was C. magnus. Response to treatment with fluconazole was fast and effective, and one year after the end of the therapy no further clinical signs of infection were observed.