Suspected thymic lymphoma with invasion of the gills in a gold crossback arowana ( Scleropages formosus).

The article provides the clinical signs and macroscopic and microscopic features of a thymic lymphoma in an arowana with a brief review of the literature. It cites a 1 year old gold crossback arowana presented to the Prasu-Arthorn animal hospital with a history of a weeklong period anorexia and delayed or lack of response to external stimuli. It describes the pathological and histophathologic findings associated with spontaneous thymic lymphoma in a gold crossback arowana.