Detection of arenavirus in a peripheral odontogenic fibromyxoma in a red tail boa (Boa constrictor constrictor) with inclusion body disease.

A captive bred red tail boa (Boa constrictor constrictor) was presented with a large intraoral mass originating from the buccal gingiva, attached to the right dentary teeth row. Based on the clinical features and histological examination, the diagnosis of a peripheral odontogenic fibromyxoma was made. Sections of liver biopsies and circulating lymphocytes contained relatively few eosinophilic intracytoplasmic inclusion bodies, indistinguishable from those observed in inclusion body disease-affected snakes. Inclusion bodies were not observed in cells comprising the neoplastic mass. Using reverse transcription polymerase chain reaction (RT-PCR), arenavirus was detected in the neoplastic tissue. Two years after surgical removal of the mass, recurrence of the neoplastic lesion was observed. Numerous large inclusion body disease inclusions were abundantly present in the neoplastic cells of the recurrent fibromyxoma. Sections of liver biopsies and circulating lymphocytes contained relatively few intracytoplasmic inclusions. The RT-PCR revealed the presence of arenavirus in blood, a liver biopsy, and neoplastic tissue. The present case describes the co-occurrence of an arenavirus infection and an odontogenic fibromyxoma in a red tail boa.