Cerebral phaeohyphomycosis in a green iguana (Iguana iguana)

Cerebral phaeohyphomycosis was diagnosed in a 4-year-old green iguana (Iguana iguana) with paroxysmal spastic paralysis of all limbs and circling motion. Formalin-fixed tissues were collected at necropsy examination and submitted for evaluation. The left cerebrum and the left ventricle were replaced by a solid brown coloured mass. Microscopical examination revealed the presence of necrotizing and granulomatous encephalitis affecting the cerebrum, cerebellum and brainstem, with severe vasculitis and intralesional dematiaceous fungal hyphae. No other lesions or fungi were found in other organs. Fungi were identified as Oidiodendron spp. by sequence analysis of the internal transcribed spacer (ITS) region 1 extracted from formalin-fixed and paraffin wax-embedded brain tissue. This case represents the first report of phaeohyphomycosis with tropism for the central nervous system in a reptile. In the absence of fresh tissue, the diagnosis in such cases may be assisted by molecular analysis of fixed tissue specimens.